Metal Components Research Articles

Atomic Structure Amorphization and Electronic Structure Reconstruction of FeCoNiCrMox High-Entropy Alloy Nanoparticles for Highly Efficient Water Oxidation.

The complexity of the multielement interaction in high-entropy alloys (HEAs) may provide more active sites to adapt different catalytic reaction steps in oxygen evolution reaction (OER). Investigating the correlation between structure and performance of HEAs electrocatalysts is both essential and challenging. In this work, FeCoNiCrMox HEAnanoparticles are successfully fabricated utilizing a unique nanofabrication method called inert gas condensation. With the increase of high-valence metal component Mo, the atomic structure amorphization and electronic structure reconstruction are unveiled. According to the X-ray photoelectron spectroscopy valence spectra, the d-band center of FeCoNiCrMox is ascending, and thus enhancing the adsorption energy. Synchrotron pair distribution function analysis reflects the degree of structural disorder and reveals a robust correlation with the intrinsic OER activities of the electrocatalysts. FeCoNiCrMo1.0 high-entropy metallic glass nanoparticles exhibit an outstanding OER performance with an ultralow overpotential of 294.5mV at a high current density of 100mAcm-2. This work brings fundamental and practical insights into the modulation mechanism of metal components of HEAs catalysts for developing OER.

Flow boiling heat transfer enhancement of R134a in additively manufactured minichannels with microengineered surfaces

Additive manufacturing (AM) of metal components has opened new frontiers in heat transfer applications owing to its wide design freedom, which enables previously unexplored geometries with enhanced thermal performance to be developed. Open minichannels, on the other hand, consist of an extra manifold situated above the common flow channels, have been demonstrated to effectively reduce pressure drop and two-phase flow instability by mitigating backflow and maldistribution. In this paper, we synergized open minichannel design methodology with an ultrascalable surface microstructuring method for AM AlSi10Mg to improve flow boiling heat transfer performance of R134a. Experiments were conducted at the refrigerant mass flow rates (ṁ) of 0.005 kg/s to 0.01 kg/s (corresponding to mass fluxes of 73 to 146 kg/m2⋅s), and effective heat fluxes (qeff) of 1.8 kW/m2 to 141 kW/m2, by supplying 2 ℃ subcooled liquid to the minichannel inlet at saturation pressure (Psat) of 7.27 bar. The effects of heat flux, nucleation site density, mass flow rate and location of nucleation sites on the harmonic-average heat transfer coefficient (have) and pressure drop (ΔP) along the flow direction are investigated and compared against a conventionally manufactured (Al6061) counterpart. Our results show that the proposed etching process significantly improves the cooling performance of AM microstrucured minichannels, resulting in 210% higher have than Al6061 with negligible pressure drop penalty. The flow visualization results reveal a sequential order of nucleation site activation with increasing heat flux for microstructured open minichannels, which starts from the top of fins, followed by the corners and other three surfaces within the channels. This also results in the non-negligible effects of mass flow rate on cooling performance for microstructured minichannels, with approximately 10%–66% higher have at the lowest mass flow rate. Besides, the pressure drop penalty resulting from plain AM rough surface is also reduced by up to 13% through the proposed microstructuring process. In all, this work not only successfully identifies the dominant mechanisms in AM microstructured open minichannels, but it also provides useful minichannel design guidelines for high-performance two-phase cooling devices by AM.

Digitally enhanced lubricant evaluation and improvement framework through developing digital characteristics (DC) for hot forging of aluminium alloys

The manufacturing sector is experiencing a never-before-seen surge in data generation, acquisition, and analytics. The promising potential of fundamental research following a data-driven approach may enable a more comprehensive understanding of forming operations and efficient optimisation of component quality. However, as a crucial component of metal forming operations, the investigation and insights from a data-centric perspective of hot forging processes is still absent. In the present study, the digital characteristics (DC) of the hot forging process was generated based on voluminous metadata extracted from experimentally verified FE simulations and localised sensors. Inherent and distinctive manufacturing nature throughout the life cycle of a hot-forged product have been revealed, spanning over the design, manufacturing, and application stages. The tribological DC was then extracted and analysed, and the data-guided interactive friction modelling was established to enable a digitally enhanced evaluation and improvement scheme of the lubricant product applied during the hot forging process. Significant potential has been demonstrated in implementing data-centric innovation techniques into traditional manufacturing paradigms to improve efficiency and process effectiveness.

Metal-Organic Framework-Derived High-Entropy Oxides as Coreaction Accelerators for an Efficient Luminol/Dissolved Oxygen Electrochemiluminescence System for Ultrasensitive Mercury Detection.

The development of luminol-dissolved O2 (luminol-DO) electrochemiluminescence (ECL) systems is crucial for real-world applications. Despite its stability and low biotoxicity, luminol-DO ECL systems struggle with low ECL performance due to their low reactivity. Investigating new materials like coreactant accelerators increases reactive oxygen species (ROS) formation and enhances luminol-DO ECL intensity. Motivated by the ROS-mediated ECL process, for the first time, we designed oxygen vacancy (OV)-rich high-entropy oxides (HEO) with five metal components [(FeCoNiCuZn)O] derived from metal-organic frameworks (MOFs) as coreaction accelerators to establish efficient luminol-DO ECL systems. High entropy (HE) MOFs were annealed at four different temperatures (600, 700, 800, and 900 °C). Indeed, the HE MOFs annealed at 800 °C (HEO-800) showed a 120-fold stronger ECL intensity compared to the bare glassy carbon electrode in the luminol-DO ECL system. The enhanced ECL performance can be attributed to the porous structure, unique morphology, heterostructures, high-density active sites, rich OV, unsaturated metals, and synergistic impact, which act as catalysts to accelerate the conversion of DO to ROS. The developed HEO-800-based luminol-DO ECL system can be effectively used for the high-sensitivity detection of mercury ions (Hg2+). The system detected Hg2+ over a wide concentration range from 0.1 nM to 100 μM, with a detection limit of 0.02 nM. The sensing mechanism relied on high-affinity metallophilic Hg2+-HEO-800 interactions, effectively quenching the ECL intensity of the luminol-DO/HEO-800 ECL system. The ECL sensing platform, developed without H2O2, offers a novel method for detecting substances, demonstrating significant potential for clinical diagnosis and biomarker analysis.

Nacre-like surface nanolaminates enhance fatigue resistance of pure titanium

Fatigue failure is invariably the most crucial failure mode for metallic structural components. Most microstructural strategies for enhancing fatigue resistance are effective in suppressing either crack initiation or propagation, but often do not work for both synergistically. Here, we demonstrate that this challenge can be overcome by architecting a gradient structure featuring a surface layer of nacre-like nanolaminates followed by multi-variant twinned structure in pure titanium. The polarized accommodation of highly regulated grain boundaries in the nanolaminated layer to cyclic loading enhances the structural stability against lamellar thickening and microstructure softening, thereby delaying surface roughening and thus crack nucleation. The decohesion of the nanolaminated grains along horizonal high-angle grain boundaries gives rise to an extraordinarily high frequency (≈1.7 × 103 times per mm) of fatigue crack deflection, effectively reducing fatigue crack propagation rate (by 2 orders of magnitude lower than the homogeneous coarse-grained counterpart). These intriguing features of the surface nanolaminates, along with the various toughening mechanisms activated in the subsurface twinned structure, result in a fatigue resistance that significantly exceeds those of the homogeneous and gradient structures with equiaxed grains. Our work on architecting the surface nanolaminates in gradient structure provides a scalable and sustainable strategy for designing more fatigue-resistant alloys.

Unveiling the Characteristics of ER70S-6 low Carbon Steel Alloy Produced by wire arc Additive Manufacturing at Different Travel Speeds

AbstractWire Arc Additive Manufacturing (WAAM) produces metal components with crucial properties dependent on process parameters. Understanding the effects of these parameters on microstructure and mechanical properties is vital for optimizing WAAM. This study investigated the impact of varying travel speeds (TS) on the microstructure and mechanical properties of low carbon steel ER70S-6 alloy produced by WAAM process. The hypothesis centred on the impact of different TS values on heat input (HI) and cooling rates, and the subsequent effects on the resulting microstructure and mechanical properties of the deposited material. ER70S-6 alloy was deposited at three different TS: 120, 150, and 180 mm/min. Microstructure and mechanical properties (microhardness, tensile strength, elongation) were evaluated for each TS condition. Distinct microstructures were observed in the deposited samples, influenced by cooling rates at different TS. Distinct microstructures emerged in different regions of the deposits due to varying cooling rates at different TS. Higher TS (180 mm/min) significantly reduced pores and cracks while enhancing yield strength (YS) and ultimate tensile strength (UTS) up to 25.2 ± 0.77% elongation and 502.3 ± 3.17 MPa UTS, respectively. However, UTS remained slightly lower (93%) than the catalogued value for ER70S-6 (540 MPa), indicating a mild softening effect. TS significantly influenced the microstructure and mechanical properties of WAAM-produced ER70S-6 alloy. This study provides key insights into optimizing WAAM parameters for low carbon steel, paving the way for improved component production for diverse industrial applications.

The Impact of an Electric Machine Body on EM Wave Propagation in RTMS

The metallic components of an electric machine exert a notable impact on the electromagnetic transmission between an external recipient and an internal shaft sensor. The RTMS (rotor temperature monitoring system) is aimed at boosting power transfer in the machine, regardless of the considerable impact of its components. This research assesses the influence of the components of an electric machine on shaft sensor transmission and specifically addresses the packaging needs of the receiver antenna. The study includes a comparative analysis of two antennas. HFSS (high frequency structure simulator) simulation was utilized to identify the antenna with a superior propagation factor. The principal contribution of this paper is the assessment of how the electrical machine body affects the transmission and propagation of rotor sensor signals, establishing a connection between these effects and the packaging criteria for the receiver antenna. Moreover, the paper presents an antenna design that capitalizes on the electrical machine body to enhance the power transmission effectiveness. The final section of this paper encompasses the experimental results obtained from the implementation of the RN171 antenna on the electrical machine, provides valuable insights into the propagation characteristics, and contributes to a comprehensive understanding of the electromagnetic dynamics within the system.

A Green Slurry Electrolysis to Recover Valuable Metals from Waste Printed Circuit Board (WPCB) in Recyclable pH-Neutral Ethylene Glycol

The continuous growth of e-waste necessitates an efficient method to recover their metal contents to improve their recycling rate. The successful recovery of the metallic component from Waste Electrical and Electronic Equipment (WEEE) can generate great economic benefits to incentivize the industrial recycling effort. In this study, we report the use of slurry electrolysis (SE) in pH-neutral ethylene glycol (EG) electrolyte to extract and recover the metallic component from waste printed circuit broad (WPCB) powder. The system operates at room temperature and atmospheric pressure, and the electrolyte can be recycled multiple times with no signs of chemical degradation. The EG electrolyte system can oxidize the metallic component without triggering anodic gas evolution, which allowed us to incorporate a reticulated vitreous carbon (RVC) foam anode to maximize the capture and oxidation of the metal content. The system demonstrated up to 99.1% Faraday efficiency for the cathodic metal deposition and could recover Cu from the WPCB powder in a selective manner of 59.7% in the presence of 12 other metals. The SE reaction system was also scalable and displayed no compromises on the Cu recovery selectivity. With the ability to leach and recover metallic content from WPCB in a mild and chemically benign condition, the SE system displayed much promise to be adapted for industrial-scale metal recovery from WPCB. Reference Liu, K., Lam, JCH. et al. "A green slurry electrolysis to recover valuable metals from waste printed circuit board (WPCB) in recyclable pH-neutral ethylene glycol." J. Hazard. Mater. 2022433: 128702.Liu, K., Lam, JCH. et al. "Teaching Electrometallurgical Recycling of Metals from Waste Printed Circuit Boards via Slurry Electrolysis Using Benign Chemicals." J. Chem. Educ. 2023 100(2): 782-790. Figure 1

Highly Durable Compositionally Variant Bifunctional Tetrametallic Ni–Co–Mn–Fe Phosphide Electrocatalysts Synthesized by a Facile Electrodeposition Method for High-Performance Overall Water Splitting

In the recent few decades, the demand for green sources of energy that are clean and sustainable became very essential to reduce the greenhouse and global warming problems. Consequently, there is an increasing demand to identify nonprecious, cheap bifunctional electrocatalysts for water splitting. Herein, nanosheets of different earth-abundant Ni, Co, Mn, and Fe combinations are electrodeposited over commercial Ti mesh and tested for the overall water splitting. The bare Ti mesh requires overpotentials of −486.6 mV at −10 mA cm–2 and 534.5 mV at 10 mA cm–2 for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. However, the electrodeposited catalysts show much higher catalytic activity for both HER and OER with overpotentials of −300 and 279 mV at −10 and 10 mA cm–2, respectively, lowering the overpotential needed to drive the OER by 50%. Nevertheless, to enhance the electrocatalytic performance of the fabricated catalysts, they are phosphidized using different phosphorous precursors. The resulted NiCoMnFe–P catalysts exhibit much lower HER overpotential (−200 mV at −10 mA cm–2), which is 40% lower than that needed by the bare Ti mesh. For the overall water splitting, a cell voltage of 1.71 V is recorded to achieve a current density of 10 mA cm–2. Lastly, the stability test of the overall device reveals very high stability with current retention of 90% over 22 h of continuous electrolysis. Furthermore, the synergy between the metallic components in the absence and presence of P is elucidated using density functional theory calculations, revealing optimized G H* and G H2O* for the HER reaction over the P-top site of the MnFeCoNiP catalyst. In addition, the calculations explain the superiority of the NiCoMnFe catalyst over the NiCoMnFeP counterpart for the OER.

Exploring the Kinetics of Oxygen Reduction Reaction in Relation to Pitting Corrosion Resistance in Fe-Cr Alloys

Pitting corrosion, a major concern in materials science and engineering, threatens critical metallic structures and components. Its implications reach across daily life and industries such as energy, transportation, and infrastructure, potentially causing environmental harm, economic losses, and even loss of life. This complex process is influenced by factors including material composition, local environment, and mechanical stresses.1 Once initiated, pit propagation rates are largely dependent on the magnitude of the supporting cathodic current available from the oxygen reduction reaction (ORR) occurring on the external passive film.2 In Fe-Cr alloys, the ORR occurs on this film, undergoing a mixed diffusion and kinetic-controlled process. The number of electrons involved and the corrosion rate are determined by the thermodynamically stable state of the passive film.This research studies the ORR kinetics on FeCr alloys fabricated by arc-melting, using both computational and experimental methods. The rotating disc electrode technique was employed across various Fe:Cr alloys in alkaline and neutral electrolytes. The Koutecky-Levich analysis showed a dominant four-electron ORR pathway in all tested Fe-Cr alloys, with the ORR significantly inhibited by higher proportions of Cr2O3 in the film, suggesting a correlation with high chromium content. Experimental ORR overpotentials, when combined with theoretical potential-pH (Pourbaix) diagrams, helped discern the likely characteristics of the passive films on the alloys. It was deduced that the catalytic properties of potential passive films increased in the order Cr2O3 < Fe3O4 < Fe2O3 < FeCr2O4. These findings, excellently aligned with density functional theory (DFT) modelling, underscore the role of increased chromium levels in slowing pitting progression by suppressing the ORR.In summary, this research offers distinctive insights into the correlation between the kinetics of the ORR and the resistance to localized corrosion in Fe-Cr alloys, which enhances our understanding of the underlying mechanisms of pitting corrosion. Keywords FeCr alloy, pitting corrosion, ORR, rotating disc electrode, DFT Reference [1] B. Zhang, J. Wang, B. Wu, X. W. Guo, Y. J. Wang, D. Chen, Y. C. Zhang, K. Du, E. E. Oguzie, and X. L. Ma, Nat. Commun. (2018) 9, 2559.[2] G. T. Burstein, P. C. Pistorius, and S. P. Mattin, Corros. Sci. (1993) 35, 57.

Cyclability Improvement of Recycled Graphite Materials in Lithium-Ion Batteries Via Conductive Polymer Coating

In recent years, lithium-ion batteries have been widely adopted in electric vehicles and electronics. However, the growing number of retired lithium-ion batteries poses a significant environmental challenge, generating substantial material waste and potential pollution. In most commercial batteries, graphite is the prevalent choice for anode material, owing to its high electrical conductivity and mechanical stability. Therefore, recycling graphite from spent lithium-ion batteries is a potential solution to eliminate the waste and meet the increasing demand.While considerable attention has been directed toward recovering metallic components of the spent lithium-ion batteries, limited effort has been dedicated to recycling graphite. Some previously developed methods include the pyrometallurgy process and hydrometallurgy process. However, due to high energy consumption and environmental pollutions, these methods have not been applied in large scales. Additionally, graphite particles have experienced various aging mechanisms during charge and discharge cycles, such as the formation of a solid electrolyte interface (SEI) and the intercalation of solvent molecules, potentially leading to structural alterations and degradation. Hence, it is advisable to implement surface treatment to enhance capacity stability if the recycled graphite does not perform optimally following the recovery treatment.In this study, we developed a simple process to recycle spent graphite utilizing aqueous and organic wash with N-Methylpyrrolidone (NMP) and toluene, followed by surface coating with the conductive polymer poly(9,9-dioctylfluorene-co-fluorenone-co-methylbenzoic ester) (PFM). The surface coating served as a protective layer of graphite particles and a charge transport agent to enhance conductivity. The morphologies and structures of the pristine, recycled, and PFM-coated recycled graphite samples were measured by X-ray diffraction (XRD) and scanning electron microscope (SEM) analysis.To investigate the impact of employing PFM as a binder, electrochemical tests were done using anodes with both recycled graphite and PFM-coated recycled graphite. In recycled-graphite||NMC532 full cell testing, cells with PFM-coated recycled graphite exhibits higher coulombic efficiency (>99.90%) than cells without PFM coating at a rate of 0.33 C. A capacity retention of 77.49% was achieved for PFM-coated cells after 300 cycles, whereas the ones without coating have a capacity retention of 70.21% in average. Rate tests were also conducted on both the cells with and without PFM-coating. It shows that both types of cells support high-rate cycling. About 85% of charge capacity was delivered for cycling at 1 C for both cells with and without PFM-coating.Overall, the recycling method can be easily operated with minimal waste production, low energy consumption, and low economical costs. The PFM coating on the recycled graphite particles leads to enhancement of mechanical strength and efficiency in battery cycling.Fig. A, The process scheme of recycling graphite; B, Pictures of an electrode from spent lithium-ion batteries (left) and an electrode fabricated with recycled graphite (right); C, Capacity retention of recycled graphite without PFM coating (blue) and with PFM coating (green); D, Coulombic Efficiency of recycled graphite without PFM coating (blue) and with PFM coating (green). Figure 1

(Invited) Industrialization of PEM Electrolyzer Stack Platforms: Driving Lab-Scale Innovation to Multi-MW Implementation

The Hydrogen production plays important role as part of energy transition strategy in Germany as well as in visions and subsequent policy of European Green Deal activities. Schaeffler [1] is driving further technological development with strong financial backing of European (CHP) and German funding (H2Giga). PEM water electrolysis is regarded as powerful technology, bringing advantages of limited installation footprint, broad range of operating conditions, especially in terms of dynamic load range and featuring high efficiency between 75-90% (based on HHV) [2].Minimizing the Levelized Cost of Hydrogen demands reduction in CAPEX, OPEX, maintenance whilst extending lifetime to secure full Return of Investment [3]. In addition, production of green hydrogen needs to anticipate the intermittent and distributed nature of renewable energy sources whilst functioning in a decentralized energy distribution network. Enabling maximum uptime sets high demands on the stack performance requirements and its material specifications. Here we show examples of how component development and design iterations make a huge impact on the commercial viability of electrolysers in industrial applications.Efficiency is key when converting renewable electricity and water into green hydrogen and other chemicals, even though PEM electrolyser stack technology is deemed capable of increasing current densities up to 10 A/cm2. Therefore, State-of-Art commercial stacks are rated at current densities between ~1-3 A/cm2, but this anticipated trend to increase power density underlines the necessity to reduce the total electrical resistance and avoid Ohm’s losses.Critical to success is selecting materials that can sustain functionality, stability and compatibility within an operational window being pushed to higher current density to increase stack output, whilst reducing PGM content and overall cost. Progress has been achieved by combining formed metal components with durable, conductive coatings, and establishing optimum compression.Most promising results published in open literature are based on small cells on laboratory scale (5-25 cm2 active area). So-called “screeners” are ideally suited for studying phenomena under well-controlled conditions with a plethora of diagnostic tools. In contrast, large-area stacks operated in the field don’t always operate under ideal operating conditions and can show variability in performance characteristics that escalate into unexpected degradation issues. Of course, stack behavior is dependent on its local environment within the BOP system, relative to its peers. We show how continuous remote monitoring during operation helps identify non-uniform stack operation and flag off-spec conditions, which could form the basis of Accelerated Stress Tests for testing in the laboratory.In this work we estimate how much stack technology can be improved further by forming BPP metal structures and optimizing the component design using CFD. Especially when scaling stack hardware to larger capacity, there is much emphasis on enhanced thermal management to avoid hot-spots and mitigate non-uniform degradation mechanisms and premature stack failure. Simulation results will show how flow designs could be adapted maintain uniform conditions when scaling up the active area or adding more cells to the stack.Robust Stacks are demanded for market ramp-up, demonstrating predictable performance over a long lifetime and insensitivity to a wide range of possible operating conditions. However, but to the best of our knowledge, no component- nor stack- supplier is willing to provide extensive guarantees. Fortunately, stacks quality can be improved significantly by strong automotive and manufacturing industries stepping into the PEM electrolyzer arena and introducing their automated assembly, mature manufacturing and controlled processes to guarantee reproducibility, tight tolerances, superior quality and support supply chain development. Before ramping up global production capacity massively, all players would benefit from standardizing general geometric specifications of stacks so we can leverage a stronger collective learning curve with increasing numbers.

(Invited) Integrated Chemocatalytic Conversion of Cellulosic Biomass to Gasoline Blended Fuel Using a Multifunctional Nano-Catalysts

The Ministry of New and Renewable Energy (MNRE) in India has initiated several programs to promote effective ways of utilizing biomass energy to boost the country's economy. In order to improve the effective use of biomass resources, the initiative for biomass power and cogeneration has adopted the use of bagasse-based cogeneration and biomass power generation in sugar mills. Because of its remarkable characteristics, including its high-octane number, low cetane number, and significant heat of vaporization, bioethanol is considered as a desirable biofuel. In addition, the increased biofuel production, in particular bioethanol, satisfies the criteria of the energy demand. These criteria include the fuel's ability to be blended with gasoline and diesel, as well as standards for low-carbon fuels.Chemocatalytic conversion using nanowire catalysts reduce side reactions caused on by an intermediate product while facilitating cascade reactions that lead to a desired product. In this work, metal oxide nanowires (TiO2 and WO3) were synthesised using a plasma-assisted method and metal nanoparticles (Pt and Ru) were impregnated on the as-synthesised NWs. In a high-pressure slurry batch reactor, reactions were carried out to obtain the optimal conditions for the desired product. The catalysts were characterised to reveal the catalysts-activity relationship. Various analytical techniques were used to quantify the liquid and gaseous products collected after the reactions.The direct conversion of cellulose to C2-C3 alcohols using tungsten-based co-catalysts was enhanced even at low temperatures. X-ray photoelectrons spectroscopy (XPS) and Raman analysis show the oxygen vacancy (Ov) enrichment on the surface of Pt/TiO2 in presence of tungsten co-catalysts which improved their catalytic activity. The role of metallic platinum (Pto) was also investigated and found to have a linear relationship with the activity as follows: H2WO4 > (NH4)6H2W12O40.xH2O > H3PW12O40 . Maximum yields of 32.33% and 51.52% of ethanol and propane-2-ol at optimum temperatures of 220℃ and 250℃, respectively, were obtained with H2WO4. Catalytic reaction performed using tandem catalytic system gives a high ethanol yield of 25.56%, which is low as compared to an integrated catalytic system. Based on the experimental results, the reaction pathway is proposed which elaborates the activation and cleavage of specific C-C and C-O bonds.Moreover, the dual functionality of tungsten oxide (WO3) nanorods as support and co-catalyst was also studied, enhances the catalytic behaviour, and the promotional study of W was studied for delivering a high yield of ethanol to 43.98% under optimum reaction conditions. The cellulose conversion was calculated to be 98.5%. The XPS study reveals the oxidation state of WO3 employing the change in catalytic activity before and after the addition of co-catalysts. The electron-deficient state of the metallic component (Ruo) is favourable for H2 adsorption on the surface, producing more active hydrogen species and thus promoting hydrogenation. As a result of these electronic understandings of Ruo and W, the reason for the higher activity of these nano synthesised Ru/WO3 compared to WO3 was concluded. Furthermore, a series of characterizations were performed to reveal the catalysts-activity relationship. Our characterization and activity test suggested that the synergistic effect of W6+ and Ruo facilitate the formation of ethanol whereas, Bronsted acid sites from W-based catalysts and Bronsted base from hot compressed water (HCW) collectively participate in the hydrolysis of cellulose and C-C cleavage of glucose to ethanol via selective hydrogenolysis of C-OH. The bond functionality was also investigated by performing reactions with various reactants under the same reaction conditions. This presentation will provide our understanding of the mechanism and kinetic correlation of the integrated cellulose-to-ethanol synthesis important for sustainable ethanol production.Correspondence should be addressed to: sreedevi@chemical.iitd.ac.in. Acknowledgments The authors thankfully acknowledge funding support from TUD-IITD MFIRP project. References Governement of India of India, BioEnergy, Ministry of New and Renewable Energy. https://mnre.gov.in/bio-energy/current-status (accessed Dec. 27, 2023).S. Achinas and G. J. W. Euverink, Consolidated briefing of biochemical ethanol production from lignocellulosic biomass, Electron. J. Biotechnol., 2016, 23: 44–53Beena Patel and Bharat Gami, Biomass Characterization and its Use as Solid Fuel for Combustion, Iran. J. Energy Environ., Iranica Journal of Energy & Environment, 2012; 3 (2):123-128N. Wei, J. Quarterman, S. R. Kim, J. H. D. Cate, and Y. S. Jin, Enhanced biofuel production through coupled acetic acid and xylose consumption by engineered yeast, Nat. Commun., 2013; 4:1–8 Figure 1

Corrosion Evaluation of Metal Binder-Jetted Stainless Steel Parts: Influence of Printing Parameters on Performance

Additive manufacturing is a rapidly expanding fabrication process in both research and industry, capable of constructing parts layer by layer from a 3D CAD model. ASTM recognizes seven distinct additive manufacturing processes, with the majority capable of producing metal components. Among these technologies, binder jetting stands out, offering the potential to create a variety of metallic parts for applications in the biomedical and energy sectors at reduced costs and shorter lead times. Achieving acceptable corrosion resistance is crucial for such applications. Binder jetting exhibits advantages such as relatively high part density (~99%) and good surface roughness (~6μm for as-sintered parts), making it an ideal candidate for investigating corrosion behavior, given the general correlation between low surface roughness, high density, and improved corrosion performance. Despite its promise, binder jetting lacks standardized procedures for producing parts with specific properties, necessitating users to determine parameters through trial and error. The corrosion behavior of parts created through binder jetting remains uncertain due to various influencing parameters. This study focuses on two key printing factors: layer thickness and binder saturation, chosen due to their impact on surface roughness, density, and thereby on corrosion. Existing literature suggests that increased layer thickness may reduce powder bed density, potentially affecting green part density and causing more significant shrinkage during sintering. Simultaneously, binder saturation is recognized as a critical factor influencing final part quality. Predicting the combined impact of layer thickness and binder saturation on corrosion performance proves challenging. To unravel this relationship, we conducted experiments using an ExOne Innovate Plus metal binder jetting machine and 316L stainless steel metal powder (mean powder size of 22μm) which is widely recognized as the most common powder in research. A number of test runs were conducted by varying layer thickness and binder saturation, offering insights into their nuanced interplay in the context of corrosion performance. Initially, to address insufficient green strength, printer drying time and curing cycle time were optimized by conducting a series of experiments changing the drying time and curing time. Subsequent printing involved changing binder saturation parallel to the layer thickness variations, resulting in distinct parts with varying properties. Then the predetermined curing cycle was executed, followed by de-powdering, and sintering in a furnace. Sintering is imperative to increase the part density and enhance the overall strength of the final product. However, it's essential to acknowledge that sintering may adversely impact corrosion resistance due to the remaining porosity and surface fissures. The choice of sintering profile becomes crucial, necessitating careful consideration to minimize elemental migration during sintering and mitigate porosity. Scanning electron microscopy and optical microscopy are used to analyze sintered parts and interpret corrosion mechanisms. Electrochemical tests were conducted to identify corrosion rates, corrosion potential, passivation behavior, pitting potential, etc. in contrast with conventionally manufactured 316L in M NaCl solution. This study offers insights and recommendations aimed at enhancing the corrosion resistance of binder jetted stainless steel parts.

Active Electrode for Ammonia Direct Utilization and the Reactivity of Metal Component in High-Temperature SOFCs

We have been conducting the international collaboration study on “Green ammonia synthesis and utilization by solid electrolysis cells for maritime application” between Germany and Japan (term:2022-2024) under the SICORP program of Japan Science and Technology Agency (JST). The contributors of this project are AIST, Kyoto University, and Morimura SOFC Technology from Japan side and Fraunhofer IKTS and EDL from German side.The purpose of this project is to establish a new concept for energy loop based on the ammonia synthesis and utilization with maritime application. The task of Japan side is to make a new anode material for direct utilization of ammonia (cracking and oxidation of NH3 component) and degradation mechanism at anode. Addition of BaO into Ni/YSZ anode improved the decomposition rates of NH3 and anode performance in NH3 fuels. We have succeeded the decomposition rate of NH3 over 99.9 % with an optimum addition amounts of BaO into Ni-YSZ electrode. An excellent performance of BaO-added Ni-YSZ cermet electrode was observed with a stable performance over 80 hours operation.Preliminary analysis using secondary ion mass spectrometry (SIMS) indicated possible nickel nitride (NiN) formation in the Ni/YSZ substrate of commercial cells exposed to NH3 and possible degradation mechanisms are considered taking into account the thermodynamics and electrochemical oxidation.This presentation will show the recent progress of this research.

Restructuring dynamics of surface species in bimetallic nanoparticles probed by modulation excitation spectroscopy

Restructuring of metal components on bimetallic nanoparticle surfaces in response to the changes in reactive environment is a ubiquitous phenomenon whose potential for the design of tunable catalysts is underexplored. The main challenge is the lack of knowledge of the structure, composition, and evolution of species on the nanoparticle surfaces during reaction. We apply a modulation excitation approach to the X-ray absorption spectroscopy of the 30 atomic % Pd in Au supported nanocatalysts via the gas (H2 and O2) concentration modulation. For interpreting restructuring kinetics, we correlate the phase-sensitive detection with the time-domain analysis aided by a denoising algorithm. Here we show that the surface and near-surface species such as Pd oxides and atomically dispersed Pd restructured periodically, featuring different time delays. We propose a model that Pd oxide formation is preceded by the build-up of Pd regions caused by oxygen-driven segregation of Pd atoms towards the surface. During the H2 pulse, rapid reduction and dissolution of Pd follows an induction period which we attribute to H2 dissociation. Periodic perturbations of nanocatalysts by gases can, therefore, enable variations in the stoichiometry of the surface and near-surface oxides and dynamically tune the degree of oxidation/reduction of metals at/near the catalyst surface.

Evaluation of energy potential of MSW in the Tamale metropolis, Ghana: An assessment of solid waste characteristics and energy content

ABSTRACT In the present investigation, a thorough examination of waste composition was undertaken in the Tamale Metropolis, Ghana. The methodology employed was carefully designed, incorporating both commercial and residential sectors as well as various socioeconomic classes. Source-based sampling of waste materials covered a range of locations, including households, markets, hotels, and restaurants, while socioeconomic-based categorization followed the zoning of the metropolis. Waste audit sampling involved collecting a total of 90 batches of solid waste over the three-month period from August to October 2023. The primary objectives were to physically characterize the waste and evaluate its chemical properties through proximate and ultimate analysis of waste fractions, aiming to determine the waste-to-energy potential and compatibility with waste-to-energy technologies. The study revealed that the Tamale Metropolis generates 176.1 tons/day of Municipal Solid Waste (MSW) at a rate of 0.47 kg/capita/day. Organic matter constituted the majority (44.9%), followed by inert, miscellaneous, and plastic waste at 20% each. The remaining 14.3% comprised paper, metal, glass, leather, and textile components. Notably, the hospitality sector exhibited the highest organic matter content at 62.3%, contrasting with average households and markets at 44.9% and 13.1%, respectively. Moisture content ranged from 5.4% to 12.6%, volatile solids from 21.8% to 77.2%, and gross calorific values from 7.9 MJ/kg to 28.9 MJ/kg. Household waste demonstrated the highest energy content at 6693.8 kcal/kg, followed by hotels/restaurants (2003.94 kcal/kg) and markets (1883.62 kcal/kg). This study’s findings offer valuable insights that can inform the development of effective policies by regulatory bodies such as the Public Utility Regulatory Commission (PURC) and the Ghana Ministry of Energy, as well as city authorities like the Tamale Metropolitan Assembly and the Environmental Protection Agency. These insights can be used to address waste and energy challenges in the metropolis. Implications: The findings reveal critical insights with substantial implications for stakeholders and regulatory bodies. It emphasizes the waste-to-energy potential of various waste fractions, highlighting the need for sustainable municipal waste management strategies. Particularly, the high organic content in the hospitality sector presents significant energy recovery opportunities. For bodies like the Public Utility Regulatory Commission and the Ghana Ministry of Energy, this data is crucial for developing policies that support waste-to-energy technologies. Additionally, the Tamale Metropolitan Assembly and the Environmental Protection Agency can use these insights to improve local waste management practices, customizing interventions to address specific sectoral waste composition. The study also underlines the importance of ongoing monitoring to ensure the effectiveness of these strategies over time.

Investigating grain-resolved evolution of lattice strains during plasticity and creep using 3DXRD and crystal plasticity modelling

Microstructure-informed crystal plasticity finite element models have shown great promise in predicting plastic and creep deformation in polycrystalline materials. These models can provide substantial insight into the design, fabrication and lifetime assessment of critical metallic components during operation, for instance, in thermal power plants. However, to correctly incorporate damage prediction into models, the microstructural strain simulated at the grain level must be accurately predicted with suitable validation. For this reason, a 3D X-ray Diffraction (3DXRD) experiment was carried out on 316H stainless steel, a material commonly used in thermal power plants, to obtain the per-grain strain response during plastic and creep deformation at 550°C. Several hundred grains within a probed X-ray volume were tracked and measured whilst loading in-situ, obtaining per-grain centre-of-mass positions, crystallographic orientations, and average lattice strain over individual grains. These data were used to calibrate a crystal plasticity model to study the plastic and creep deformation using macroscopic stress-strain and stress-relaxation data. Subsequently, the model was used to predict the average elastic strain in different grains during the cyclic creep experiment, which was validated by 3DXRD datasets. The model results reveal that {100} or {311} grain families are strongly sensitive to microstructure, thereby a polycrystal model that describes specific orientation and neighbourhood characteristics is essential to predict the local response of these grain families. Whereas, self-consistent models are suitable for {110} and {111} grain families. This study shows that only with a suitable calibration of subsurface grain behaviour, crystal plasticity models reveal grain characteristic-dependent micromechanical behaviour.

Mechanical behavior and seismic control performance of a metallic torsional damper for flexible structures

The use of metallic dampers is an effective way to reduce seismic responses and dissipate excessive vibration energy for civil structures. Conventional metallic dampers employed energy dissipation by plastic deformation under bending or shear modes are hard to design, and may cause uniform distribution of stress in the metallic components. In this paper, employing the high plastic deformation capacity of aluminum materials, a metallic torsional damper using a gear and rack device (MTDGRD) is proposed to enhance the control effectiveness for the structural response reduction under earthquakes. The static mechanical behavior and energy dissipation of aluminum metallic components under torsional deformation are experimentally studied. Moreover, the configuration and working principle of the proposed damper are introduced. The dynamic behavior of the proposed damper is experimentally studied. For precise modeling in simulations, the elastic-plastic theory of torsional deformation is used to derive the mechanical model of the proposed damper and the model accuracy is validated by experimental data. Finally, numerical simulations under different seismic ground motions controlled by a proposed MTDGRD are compared to that controlled by a conventional tuned mass damper (TMD) for a 10-floor flexible structure. The results show that aluminum 6061# of the energy dissipation capacity is higher than aluminum 1060#. The dynamical tests show that the loading frequency and operational cycles have very limited effect on mechanical behavior and energy consumption capacity of the MTDGRD. The proposed dynamic mechanical model of the MTDGRD has considerable accuracy in numerical simulations and seismic control simulations show the better performance of the proposed damper in reducing structural displacement responses than the conventional TMD with a mass ratio of 0.5 %.

Corrosion inhibition performance and adsorption mechanism of new synthesized symmetrical diarylidenacetone-based inhibitor on C38 steel in 15 % HCl medium: Theoretical insight and experimental validation

Despite the engineering potential of using organic substances to protect vulnerable metallic materials from corrosive environments, the interaction mechanisms and adsorption processes that lead to the formation of hybrid materials remain poorly understood. Further research is necessary to elucidate how these organic compounds interact with metallic surfaces and the specific pathways through which they adsorb to form protective layers. Understanding these mechanisms is crucial for developing more effective corrosion-resistant hybrid materials, which could significantly enhance the properties of metallic components and provide excellent electrochemical stability in various industrial applications. This work aims to explore the corrosion performance and interfacial mechanism of two symmetrical diarylidenacetone-based compounds, namely, (1E,4E)-1,5-bis(4-methoxyphenyl) penta-1,4-dien-3-one (MPD) and 2,6-di((E)-benzylidene) cyclohexan-1-one (BZC), in a bid to control the corrosion kinetics of C38 steel in aggressive environment. This assessment integrated experimental, surface, and theoretical explorations. The results of our study revealed the remarkable ability of MPD and BZC molecules to generate a dense, resistant protective film on the C38 steel surface. This protective film acted as a barrier, effectively blocking the penetration of corrosive ions and their interaction with the C38 substrate. The inhibition efficiencies of the investigated products exhibited a consistent rise with increased amounts of additives. The inhibition efficiency reached 95 % for MPD and 90 % for BZC at 10−3 M, as calculated from the fitting Nyquist diagrams. The interaction between the inhibitor and Fe(110) was studied utilizing density functional tight binding (DFTB) and Molecular dynamics simulations (MDS). The results demonstrate the formation of covalent bonds, with the molecules aligning in a parallel orientation of MPD and BZC. This alignment with experimental findings provides strong validation for the efficacy of the inhibitors in corrosion inhibition.