Direct Ethanol Research Articles

Enhanced ethanol synthesis via CO2 hydrogenation using La-Doped CuFeOx catalysts

CO2 hydrogenation is an effective solution for direct ethanol production as it realizes a high-value utilization of waste CO2. As it requires a synergistic multi-step process of CO2 activation, asymmetric hydrogenation of CO, and precise coupling of C-C bonds, the design of highly active and selective catalysts for such procedures remains challenging. In this study, we prepared a series of La-doped CuFe catalysts using a simple and green solvent-free ball milling method to accelerate the rate of CO2 hydrogenation to ethanol generation. HRTEM, in situ XRD, EPR, and CO2-TPD analyses indicated that the doping of moderate amounts of La can significantly improve the dispersion of the Cu and Fe species, enhance the interaction between the CuFe species, decrease the reduction temperatures of CuO and Fe2O3, promote the formation of oxygen vacancies during the reaction process, and enhance CO2 adsorption and activation ability. DFT calculations, XPS, in situ FTIR, and CO-TPSR-MS analyses indicated that the transfer of electrons from the Fe to La species decreased their electron cloud densities, weakened the bridge type adsorption of CO, enhanced the linear adsorption of CO, and optimized the ratio of the dissociative and non-dissociative adsorption of CO intermediates, which ultimately resulted in a better matching of the rates of generation of CHx* and C(H)O* intermediates. The occurrence of C-C coupling at the abundant Cu0-Fe5C2 interface promoted the highly efficient synthesis of ethanol, achieving yields as high as 13.5 % over the 5La-CuFeOx catalyst, ranking the top level among the reported catalysts in the literature. This study presents a feasible strategy for the targeted regulation of multicomponent active centers.

The Effect of Saccharin on SnNi Alloy: the Electrodeposition and its Electrocatalytic Activity in Ethanol Oxidation Reaction

The development of Direct Ethanol Fuel Cell (DEFC) has attracted much attention, as alternative energy sources due to its various advantages. However, among its various advantages, DEFC has several problems, such as the kinetics of the ethanol oxidation reaction. Transition metal-based catalysts such as nickel and tin are considered as potential catalysts for DEFC due to their oxophilic properties that can improve catalytic activity. In this study, the effect of saccharin on SnNi bimetallic alloy catalyst synthesized by electrodeposition method on copper wire substrate was investigated. SnNi samples were characterized by several techniques, including X-ray diffraction, Scanning electron microscopy, and energi dispersive X-ray spectrocopy. Saccharin addition had a significant effect on the morphology, crystallite size, and composition of the catalyst. The presence of saccharin causes the formation of more uniform particles and has a smaller size. The sample with the addition of saccharin had a smaller charge transfer resistance value 4.82 Ω, lower tafel slope by 115 mV/dec, and show higher jf/jb ratio by 0.55. Furthermore, as the current density decreases, the SnNi catalyst with saccharin has a slow decrease rate and higher stability than the SnNi catalyst without saccharin.

Outstanding Activity and Durability of Supported NiCo2O4 Nanoparticles for Direct Ethanol Fuel Cells

ABSTRACTThe rational design of noble metal‐free electrocatalysts represents one of the basic stones for fuel cell development. With the exploration of eco‐friendly nanomaterials for the investigated alcohol oxidation process, nickel‐based electrodes have been recognized as the most auspicious anodes with promoted activity and stability. In this work, a series of NiCo2O4 nanoparticles were deposited onto graphite sheets (NiCo2O4/T) introducing varied proportions of cobalt oxide species. Co‐precipitation protocol of the respective metallic hydroxides onto the carbonaceous support was followed with consecutive annealing in an air atmosphere at 400°C. The fabricated mixed metallic oxide nanopowder was physically studied using X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X‐ray analysis (EDX), X‐ray photoelectron spectroscopy (XPS), and selected area electron diffraction (SAED). Uniformly arranged nanoparticles were observed on graphite surface as evidenced by SEM and TEM. The cubic lattice structure of formed NiCo2O4 crystals was also confirmed by XRD through the defined peaks of binary metallic oxides clarifying their successful preparation scheme. The electrocatalytic properties of these NiCo2O4/T nanocatalysts were evaluated for oxidizing ethanol molecules in basic solution. Pronounced oxidation current densities were remarkably measured at NiCo2O4/T electrodes in relation to that at NiO/T. Differing the introduced cobalt oxide content into the synthesized nanocatalyst significantly controlled its catalytic performance. NiCo2O4/T‐20 exhibited the highest activity and stability among the prepared nanomaterials. Much decreased charge transfer resistances were also recorded at this electrode demonstrating its promoted electron transfer characteristics. This work could provide a reasonable route for the simple synthesis of comparable transition metallic oxides with promising attitudes for energy generation purposes.

Liquid Metal Electrocatalyst with Ultralow Pt Loading for Ethanol Oxidation

Developing efficient and durable electrocatalysts for ethanol electro‐oxidation is crucial for enabling the application of direct ethanol fuel cell technology. Herein, it is demonstrated that Pt–Ga liquid metal‐based nanodroplets can serve as an efficient electrocatalyst to drive ethanol oxidation. The mass activity of Pt is significantly improved by alloying with liquid gallium. Guided by machine learning neural networks, a low‐concentration alkaline electrolyte is specifically formulated to allow electrodes with ultralow Pt loading to demonstrate remarkable activity toward ethanol oxidation with a mass activity as high as 13.47 A mg−1Pt, which is more than 14 times higher than that of commercial Pt/C electrocatalysts (i.e., 0.76 A mg−1Pt). Computational studies reveal that the superior activity is associated with the presence of Ga oxides adjacent to Pt on the catalyst surface which leads to energetically favorable pathways for the oxidation process. The findings reveal untapped opportunities in the realm of liquid metal catalysis and hold great promise for the future development of high‐performance alcohol fuel cells.

PtCu-a-SnO2 interface engineering on PtCu-SnO2 aerogels for ethanol oxidation electrocatalysis

Designing catalysts with high activity and stability to boost their ethanol oxidation reaction (EOR) performance is one of the central targets in the development of direct ethanol fuel cells (DEFCs). However, how to design the EOR catalysts in a rational way is still challenging, needing more efforts put in. Herein, we have synthesized a catalyst of PtCu-SnO2 aerogel via ingeniously introducing Cu into Pt-SnO2 system, resulting in the formation of a main phase of alloy (PtCu)-amorphous oxide (a-SnO2) interface. Benefiting from the optimized structures, the PtCu-SnO2 aerogel displays excellent acidic EOR performance with 4.5 times promotion in activity compared to pure Pt aerogel. In-depth investigations through electrochemical in-situ Fourier transform infrared spectroscopy and density functional theory calculations have shown that the absorbed OH on a-SnO2 surface together with the greatly-modified electronic structure of the alloy surface atoms can facilitate the C1 pathway and the oxidation of *CO intermediates for ethanol oxidation reaction. The resulting affinity of surface OH and the modification of reaction energies both in turn contribute to the improvement of EOR performance with high activity, stability, and anti-poisoning ability, proving interfacial engineering an effective strategy for the rational design of EOR catalyst.

B-260 Prevalence and Relative Distributions of Major Phosphatidylethanol (PEth) Homologs in a Large-Scale Clinical Study

Abstract Background Ethanol abuse remains a significant public health challenge in the United States. Detection of ethanol exposure is crucial for preventive, diagnostic, and therapeutic endeavors. Phosphatidylethanol (PEth) is a specific and direct ethanol biomarker. Compared to other metabolites, such as ethyl glucuronide and ethyl sulfate in urine (average 2-3 days), PEth in blood has a longer window of detection (average 1-2 weeks). Among the known 48 PEth homologs, PEth 16:0/18:1 (POPEth) and PEth 16:0/18:2 (PLPEth) are the most abundant species accounting for 37% to 46% and 26% to 28%, respectively. PLPEth is synthesized at a greater rate than POPEth, but POPEth has a longer half-life than PLPEth. The purpose of this study was to understand the prevalence and levels of POPEth and PLPEth in a large number of clinical specimens. Methods Briefly, lavender-top whole blood specimens were diluted with isotopically labeled internal standard (IS) in an organic buffer to precipitate proteins on an automated Hamilton platform. The mixture was centrifuged, and a supernatant portion isolated for injection onto a Sciex QTRAP 5500 liquid chromatography tandem mass spectrometry (LC-MS/MS) system using electrospray ionization (ESI) in negative mode. The assay was fully validated under CLIA regulations for lab developed tests: the analytical measurement range (AMR) was 10-400 ng/mL; the administrative reporting threshold for PEth positivity was 20 ng/mL based on clinical literature and a consensus among other United States laboratory methods. Results Precision of 4 QC levels was evaluated with between-run CV% (n=25) ranging from 1.6-6.3%, and accuracy across the AMR was achieved with 87-110%. No significant matrix effects were observed; variation in different whole blood specimens was corrected with IS normalization. No significant interferences were observed from 137 commonly seen prescription and nonprescription drugs and 6 other PEth homologs. Of the clinical specimens, most (20,833, 71.3%) were negative (<20 ng/mL) for both analytes. Meanwhile, 8,222 specimens (28.3%) were positive with either POPEth, or PLPEth or both ≥ 20ng/mL. There were 150 specimens excluded from the statistics due to interference challenges. Interestingly, 757 specimens (2.6%) were PLPEth negative and POPEth positive (mean value 40.1 ng/mL). Conversely, 62 specimens (0.2%) were POPEth negative and PLPEth positive (mean value 24.6 ng/mL). Among the specimens with both POPEth and PLPEth levels within the AMR, the average POPEth/PLPEth ratio was 1.4 supporting the overall prevalence of higher POPEth concentrations than PLPEth. However, the POPEth/PLPEth ratio varied widely, from 0.3 to 8.8, reflecting patient differences in PEth metabolism patterns. Conclusions To help verify probable ethanol abstinence, we have developed, validated, and deployed a high-throughput clinical assay for the major PEth homologs, POPEth and PLPEth. In a retrospective analysis of 29,205 clinical specimens: 71.3% of results were consistent with abstinence; 28.3% of the results were positive suggesting moderate alcohol consumption within the last 1-2 weeks. With POPEth most prevalent, yet variation observed, there were 62 specimens with PLPEth positive and negative for POPEth. This clinical PEth study including both POPEth and PLPEth provides greater sensitivity to identify ethanol exposure than only testing a single homolog.

Integrating fuzzy modelling and war strategy optimization for identifying optimal operating factors of direct ethanol fuel cell

-Operating factors, including temperature, pressure, alcohol concentration, and reactant flow rate, significantly impact how much energy is produced by direct alcohol fuel cells. The cell's performance may go down or up depending on how these factors vary. For instance, greater alcohol temperatures and concentrations can speed up reactions and boost fuel cell efficiency, whereas lower alcohol temperatures and concentrations can have the opposite effect. Consequently, optimizing the operating circumstances is essential to getting the most energy possible out of direct alcohol fuel cells. Therefore, the primary goal is to develop a solid fuzzy model to simulate direct ethanol fuel cells (DMFC). Three process variables—ethanol flow rate, ethanol concentration, and temperature—are considered to increase the power density of DEFC. First, a fuzzy model of the DEFC was developed using experimental data. The best operating conditions to increase power density are then determined using war strategy optimization (WSO). Thanks to fuzzy, the RMSE decreased from 0.529 using RSM to 0.0292 using fuzzy (decreased by 94.5 %), compared to 0.529 using RSM. By around 11.7 %, the squared-R for prediction increases from 0.88 (using RSM) to 0.9831 (using fuzzy). The fuzzy model's low RMSE and high R-square values show the successful modelling phase. Compared to measured data and RSM, integrating fuzzy and WSO increased DEFC's power density by 5 % and 7.26 %, respectively. The ideal ethanol flow rates, concentrations, and temperatures are 9.4 ml/min, 0.25 M, and 74C, respectively.

Bimetallic Rh–Pd aerogels as efficient materials for ethanol electrooxidation

This study introduces a series of Rh–Pd bimetallic aerogels Rh75Pd25, Rh50Pd50, and Rh25Pd75 as efficient electrocatalysts for ethanol electrooxidation, crucial for direct ethanol fuel cell technology. The bimetallic Rh–Pd and monometallic Rh and Pd aerogels were synthesized from RhCl3 and PdCl2 as starting materials and sodium borohydride as the reducing agent. A combination of X-ray photoelectron spectroscopy, elemental mapping, and electron microscopy studies of the bimetallic aerogels enable compositional analysis of the materials and provide insight into the porous 3D nanoarchitecture. Importantly, the material performs efficiently as an electrocatalyst on glassy carbon electrodes for the oxidation of ethanol under basic conditions (1.0 M KOH) at onset potentials ranging from −0.59 to −0.64 V (vs. Hg/HgO). Importantly, these materials exhibit high peak current densities of 216 mA/cm2 for the Rh-rich Rh75Pd25 to 536 mA/cm2 for Rh25Pd75, which are significantly higher than reported peak current densities for other Pd-containing electrocatalysts. The 1H and 13C NMR techniques were used to evaluate products for ethanol electrooxidation, with the results indicating selectivity for acetic acid. This demonstrates an enhanced catalytic activity, selectivity to acetic acid vs. CO2, representing a significant step in advancing DEFCs and their broader application in sustainable energy technologies.

Synthesis of palladium-rare earth alloy as a high-performance bifunctional catalyst for direct ethanol fuel cells

Synthesis of palladium-rare earth alloy as a high-performance bifunctional catalyst for direct ethanol fuel cells

Enhancing the Catalytic Activity of Pd Nanocatalysts for Anion Exchange Membrane Direct Ethanol Fuel Cells by Functionalizing Vulcan XC-72 with Cu Organometallic Compounds.

The most widely used support in low-temperature fuel cell applications is the commercially available Vulcan XC-72. Herein, we report its functionalization with the home-obtained mesityl copper (Cu-mes) and Cu coordinate (Cu(dmpz)L2) organometallic compounds. Pd nanoparticles are anchored on the supports obtaining Pd/CCu-mes, Pd/CCu(dmpz)L2, and Pd/C (on nonfunctionalized support). The polarization curves of the ethanol oxidation reaction (EOR) show that Pd/CCu-mes and Pd/CCu(dmpz)L2 promote the reaction at a more negative onset potential, i.e., E onset = 0.38 V/reversible hydrogen electrode (RHE), compared to 0.41 V/RHE of Pd/C. The mass current density (j m) delivered by Pd/CCu-mes is considerably higher (1231.3 mA mgPd -1), followed by Pd/CCu(dmpz)L2 (1001.8 mA mgPd -1), and Pd/C (808.3 mA mgPd -1). The enhanced performance of Pd/CCu-mes and Pd/CCu(dmpz)L2 for the EOR (and tolerance to CO poisoning) is attributed to a shift of their d-band center toward more negative values, compared to Pd/C, because of the formation of PdCu alloyed phases arising from the functionalization. In addition, laboratory-scale tests of the anion exchange membrane-direct ethanol fuel cell assembled with Pd/CCu-mes show the highest open circuit voltage (OCV = 0.60 V) and cell power density (P cell = 0.14 mW cm-2). As a result of its high catalytic activity, Pd/CCu-mes can find application as an anode nanocatalyst in AEM-DEFCs.

Determination of optimal operating conditions for bioelectrolyte fuel cells using ADH as anode catalyst and solidification of fuel

Enzyme-based direct ethanol fuel cells (DEFCs) have the potential to become the next generation of energy devices without platinum catalysts. However, the development of DEFCs requires the search for new electrolytes that are compatible with ethanol fuel and enzymes. In this study, DEFCs with a combination of chitin electrolytes and ADH were fabricated and characterized. DEFCs using chitin electrolyte were also investigated for various ethanol fuel concentrations, and it was found that DEFCs using 50 mM ethanol achieved the highest power density. In addition, enzyme activity was measured and showed a maximum value when 50 mM ethanol was used, suggesting that the proton production reaction catalyzed by the enzyme determines the maximum power density of the bioelectrolyte DEFC. Furthermore, we successfully fabricated a highly portable solid bio-electrolyte DEFC and found that it achieved a maximum power density of 0.11 mW/cm2 at an ethanol concentration of 25 %.

Improving durability and efficiency in passive direct ethanol fuel cells using a biodegradable polyvinyl alcohol/epoxidized natural rubber membrane

AbstractIn this study, a novel biodegradable polymer electrolyte membrane with reduced fuel crossover, high selectivity, and high conductivity compared with Nafion 117 membrane in direct ethanol fuel cells (DEFCs) has been reported. Herein, polyvinyl alcohol/epoxidized natural rubber (PVA/ENR) blend membranes were synthesized via a simple solution casting method and applied in DEFCs. The structural and physicochemical features of the PVA/ENR blend membranes were examined using FESEM, FTIR, XRD, water absorption, ethanol uptake, swelling ratio and oxidative stability. ENR enhances the chemical, structural, and mechanical characteristics of PVA, making it a valuable material in fuel cell applications. The incorporation of ENR into the PVA matrix results in a compact morphology, excessive multifunctional groups, low fuel crossover, and high selectivity. The optimum membrane thickness achieves the highest selectivity, reaching up to 12.32 × 104 S s cm−3 at 30°C. Additionally, the maximum power density achieved is 19.52 mW cm−2, surpassing that of the Nafion membrane, which is only 14.55 mW cm−2 at 90°C. Furthermore, this biodegradable membrane can sustain operation for 1000 h at 90°C, owing to its ability to maintain hydration for an extended period. This study represents the first attempt to combine PVA and ENR in fuel cells.

2D PtRhPb Mesoporous Nanosheets with Surface-Clean Active Sites for Complete Ethanol Oxidation Electrocatalysis.

The development of active and selective metal electrocatalysts for complete ethanol oxidation reaction (EOR) into desired C1 products is extremely promising for practical application of direct ethanol fuel cells. Despite some encouraging achievements, their activity and selectivity remain unsatisfactory. In this work, it is reported that 2D PtRhPb mesoporous nanosheets (MNSs) with anisotropic structure and surface-clean metal siteperform perfectly for complete EOR electrocatalysis in both three-electrode and two-electrode systems. Different to the traditional routes, a selective etching strategy is developed to produce surface-clean mesopores while retaining parent anisotropy quasi-single-crystalline structure without the mesopore-forming surfactants. This method also allows the general synthesis of surface-clean mesoporous metals with other compositions and structures. When being performed for alkaline EOR electrocatalysis, the best PtRhPb MNSs deliver remarkably high activity (7.8 A mg-1) and superior C1 product selectivity (70% of Faradaic efficiency), both of which are much better than reported electrocatalysts. High performance is assigned to multiple structural and compositional synergies that not only stabilized key OHads intermediate by surface-clean mesopores but also separated the chemisorption of two carbons in ethanol by adjacent Pt and Rh sites, which facilitate the oxidation cleavage of stable C─C bond for complete EOR electrocatalysis.

Using umbilical cord tissue to identify prenatal ethanol exposure and co-exposure to other commonly misused substances.

Substance misuse during pregnancy can result in a variety of poor pregnancy outcomes. Objective data reporting the prevalence of neonates born with ethanol metabolites (evidence of prenatal ethanol exposure) in their fluids or tissues are limited. A secondary analysis of umbilical cord tissue specimens received for routine toxicological analysis was conducted. Prevalences of ethyl glucuronide (EtG), a long-term direct ethanol biomarker, were determined using a new laboratory tool, LDTD-MSMS. Additionally, other commonly misused substances were determined using routine procedures. Of 12,995 specimens, 238 (1.8%) specimens contained EtG. Concentrations of EtG ranged from 5 ng/g to 6679 ng/g (median 47 ng/mg; IQR: 16 ng/g, 203 ng/g). Of those 238 EtG-positive specimens, nearly 58% (N = 138) contained additional substances or metabolites. Self-report of substance use during pregnancy is under-reported. We have demonstrated co-exposure of substances with ethanol is higher than previous reports.

Plasmon-enhanced electrocatalytic ethanol oxidation over Au@Pd nanostars

Hybrid noble-metal nanostructures, which integrate plasmonic characteristics and electrocatalytic performance, have garnered significant interest recently. In this study, Au@Pd nanostars were synthesized and employed as an advanced electrocatalyst for the ethanol oxidation reaction (EOR), which suffers from the kinetic limitations of the anodic half-reaction of direct ethanol fuel cells. Leveraging the superior surface plasmon resonance (SPR) property of Au nanostars, the synthesized Au@Pd nanostars exhibited superior plasmon-enhanced EOR activity of 4191.63 A g−1 under laser illumination, noting a 9.40-fold increase compared to dark conditions (445.99 A g−1). The influences of Pd loading and laser power on EOR activity were explored. The impact of Pd loading on EOR activity demonstrates a volcano-shaped correlation, where optimal Pd coverage enhances catalysis but excessive amounts dampen SPR performance, crucial for maximizing EOR activity. Within a specified range, EOR activity linearly increases with laser power due to its influence on SPR performance. Mechanistic investigation suggests the critical roles of photothermal effect and hot carriers’ separation in boosting EOR kinetics. The repeated experiments show little difference, ensuring the accuracy and reproducibility of the reported activity of Au@Pd nanostars for EOR. During the long-term stability estimation, the Au@Pd nanostars display the best durability over three electrocatalysts. Overall, our findings highlight the potential of plasmon-enhanced catalysis in advancing the performance of electrocatalysts for EOR and other conventional electrocatalytic reactions.

Investigation of an Ethanol Electroreforming Cell Based on a Pt1Ru1/C Catalyst at the Anode

The production of H2 from renewable sources represents a crucial challenge for the planet’s future to achieve net zero emissions and store renewable energy. A possible alternative to water electrolysis (WE), which requires high potential (E > 1.48 V) to trigger the oxygen evolution reaction (OER), would be alcohol electrochemical reforming (ER), which implies the oxidation of short organic molecules such as methanol or ethanol. In ER, energy must be supplied to the system, but from a thermodynamic point of view, the energy request for the methanol or ethanol oxidation reaction is much lower than that of the OER. To study this process, an in-house 50 wt.% Pt1Ru1/C anodic catalyst was easily synthesized according to the Pt sulphite complex route and the impregnation of a carbon support (Ketjenblack, KB) and a Ru precursor. X-ray diffraction (XRD), X-ray fluorescence (XRF) spectroscopy, and Transmission Electron Microscopy (TEM) were used to characterize the structure, composition, and morphology of the catalyst. It appears that two distinct crystallographic phases of the Pt and Ru nanoparticles were encountered after the synthesis conducted by Ru impregnation. For the electrochemical measurements, ethanol electrooxidation (2 M CH3CH2OH) was studied first in a half cell with a rotating disc electrode (RDE) configuration under acid conditions and then in a direct ethanol electroreforming (or electrolysis) cell, equipped with a proton exchange membrane (PEM) as the electrolyte. The output current density was 0.93 A cm−2 at 1 V and 90 °C in 2 M ethanol. The remarkable current densities obtained in the alcohol electrolyzer at a low voltage are better than the actual state of the art for PEM ethanol ER.

Systematic combination of palladium facets and monolayer metal hydroxide nanosheets for promotion of ethanol oxidation reaction

The design of catalyst surfaces that exhibit high activities for ethanol oxidation reaction (EOR) is essential to achieving practical application of direct ethanol fuel cells. Composite catalysts of Pd nanoparticles and metal hydroxide are promising candidates for EOR; however, a guide of catalyst design, including appropriate valence states and interfacial structures between component materials, has not been identified. Herein, we synthesize composite electrocatalysts of cubic and octahedral Pd nanocrystals with well-defined facets and monolayer metal hydroxide nanosheets with an identical structure and different composition containing Ni, Fe and Mn, and systematically elucidate highly active interfacial sites between Pd and metal hydroxides for EOR. Promotion of OH− adsorption by the hydroxide nanosheets enhances the catalytic activities of the Pd nanocrystals and the nanosheet having higher affinity to OH− result in higher EOR performances of the composite catalysts. The improved activities are greater for (111) facet than for (100) facet of the Pd whereas the (100) facet is superior for EOR to the (111) facet for the bare Pd nanocrystals. Our study suggests that combination of the Pd (111) facet and metal hydroxides is favorable for developing highly active electrocatalysts for EOR.

Candle Soot as a Novel Support for Nickel Nanoparticles in the Electrocatalytic Ethanol Oxidation.

The enhancement of carbon-supported components is a crucial factor in augmenting the interplay between carbon-supported and metal-active components in the utilization of catalysts for direct ethanol fuel cells (DEFCs). Here, we propose a strategy for designing a catalyst by modifying candle soot (CS) and loading nickel onto ordered carbon soot. The present study aimed to investigate the effect of the Ni nanoparticles content on the electrocatalytic performance of Ni-CS, ultimately leading to the identification of a maximum composition. The presence of an excessive quantity of nickel particles leads to a decrease in the number of active sites within the material, resulting in sluggishness of the electron transfer pathway. The electrocatalyst composed of nickel and carbon support, with a nickel content of 20 wt%, has demonstrated a noteworthy current activity of 18.43 mA/cm2, which is three times that of the electrocatalyst with a higher nickel content of 25 wt%. For example, the 20 wt% Ni-CS electrocatalytic activity was found to be good, and it was approximately four times higher than that of 20 wt% Ni-CB (nickel-carbon black). Moreover, the chronoamperometry (CA) test demonstrated a reduction in current activity of merely 65.80% for a 20 wt% Ni-CS electrocatalyst, indicating electrochemical stability. In addition, this demonstrates the great potential of candle soot with Ni nanoparticles to be used as a catalyst in practical applications.

Rhodium-decorated palladium nanocubes supported on Ni(OH)2 nanosheets/C for enhanced ethanol oxidation

This study investigates the improvement of Palladium (Pd)-based nanocatalysts for ethanol oxidation in alkaline solutions, a process often hindered by the poisoning of the catalyst’s surface. We synthesise Pd nanocubes and Rhodium (Rh)-decorated Pd nanocubes, both supported by a composite of nickel hydroxide nanosheets and carbon (Ni(OH)2/C). The developed Pd nanocatalysts possess a nanocubic morphology with smaller sizes compared to Pd/C, alongside additional nanostructures like nanorods X-ray absorption near-edge structure and extended X-ray absorption fine structure analyses suggest that Rh decoration on Pd nanocubes prevents Pd oxidation, with Rh itself being oxidised. The electrocatalytic performance of the Rh/Pd/Ni(OH)2/C hybrid catalyst displays a notable enhancement, attributed to the combined effects of the exposed Pd (100) crystal surfaces, the addition of oxygenated species through the Ni(OH)2 component, and the deliberate addition of Rh. Comparative assessments reveal that this composite surpasses Pd/C and Pd/C nanocubes, achieving specific activities that are approximately 11.6 and 3.5 times greater, respectively. Electrochemical Impedance Spectroscopy data and chronoamperometric studies confirm superior ethanol oxidation efficiency and improved catalytic stability. These findings highlight the utility of Rh/Pd/Ni(OH)2/C nanocubes in direct ethanol fuel cells, providing promising pathways for enhancing fuel cell technologies.

PdSnW Ternary Alloy Nanoparticle with Excellent CO Anti‐Poisoning Activity for Boosting Alkaline Ethanol Oxidation Reaction

AbstractEfficient ethanol oxidation reaction (EOR) catalysts with anti‐poisoning ability and high selectivity are in high demand for the widespread application of direct ethanol fuel cells (DEFCs). Here, the PdSnW ternary alloy nanoparticles are synthesized by a facile solvothermal method and exhibit an enhanced EOR catalytic performance. CO stripping experiment, X‐ray photoelectron spectroscopy and in situ Fourier transform infrared are employed to study the correlation between catalyst structure and EOR catalytic performance. The oxyphilic Sn and W not only provide dangling O−H bond, accelerating the subsequent oxidation of adsorbed intermediate CO species, but also moderate the electron state of Pd, enhancing the adsorption of CH3CH2OH, thus resulting in the promotion of C−C bond cleavage and an increased C1 selectivity. As a consequence, PdSnW alloy nanoparticle catalyst exhibit a better stability and a higher mass activity than those of Pd/C, PdSn and PdW, respectively. This work not only offers novel insights to strategically design highly efficient electrocatalysts for ethanol oxidation, but also further clarifies the inherent structure‐activity relationship.