Potential Catalyst Research Articles

Unlocking Efficiency: Minimizing Energy Loss in Electrocatalysts for Water Splitting.

Catalysts play a crucial role in water electrolysis by reducing the energy barriers for hydrogen and oxygen evolution reactions (HER and OER). Research aims to enhance the intrinsic activities of potential catalysts through material selection, microstructure design, and various engineering techniques. However, the energy consumption of catalysts has often been overlooked due to the intricate interplay among catalyst microstructure, dimensionality, catalyst-electrolyte-gas dynamics, surface chemistry, electron transport within electrodes, and electron transfer among electrode components. Efficient catalyst development for high-current-density applications is essential to meet the increasing demand for green hydrogen. This involves transforming catalysts with high intrinsic activities into electrodes capable of sustaining high current densities. This review focuses on current improvement strategies of mass exchange, charge transfer, and reducing electrode resistance to decrease energy consumption. It aims to bridge the gap between laboratory-developed, highly efficient catalysts and industrial applications regarding catalyst structural design, surface chemistry, and catalyst-electrode interplay, outlining the development roadmap of hierarchically structured electrode-based water electrolysis for minimizing energy loss in electrocatalysts for water splitting.

Ni-Doped Activated Carbon from Invasive Plants as a Potential Catalyst

In this study we synthesized and characterized Ni/AC (Activated Carbon) systems. AC was obtained through pyrolysis of golden rod’s dried biomass. Ni nanoparticles were deposited on AC’s surface using a wet impregnation method from a nickel nitrate solution. SEM, MP-AES and DSC-TGA techniques were used for surficial and structural characterization, while ash content was made to check mineral ingredients input. The DSC-TGA study revealed that all carbons show good thermal stability up to 900 °C, which is far above operating temperatures in the methanation process. For all three carbons the BET isotherms were made as well. They show that in most cases the carbon’s surface is well developed and can adsorb decent amounts of metal. MP-AES helped to evaluate the efficiency of the impregnation process, which reached 76 mg of Ni per 1 g of carbon. The SEM-EDS study showed good distribution of Ni nanoparticles across AC’s surface. We also made a comparison of our systems to similar materials from other works.

Computational study on graphdiyne supported PdxCuy clusters as potential catalysts for formic acid dehydrogenation

Designing low-cost and efficient catalysts for formic acid dehydrogenation (FAD) is crucial to facilitate the practical applications of formic acid as a hydrogen carrier. Using density functional theory calculations, we designed nine graphdiyne-supported Pd/Cu single-, double-, and triple-atom catalysts, investigating their stability and formic acid dehydrogenation performance. The results indicate that as the number of active metal sites increases, the catalytic activity for formic acid dehydrogenation improves, i.e., M3@GDY > M2@GDY > M1@GDY (M = Pd/Cu). Moreover, a synergistic effect between Pd and Cu atoms is observed in PdxCu3-x@GDY, where the activity sequence of triple-atom catalysts was Pd1Cu2@GDY > Pd2Cu1@GDY > Pd3@GDY > Cu3@GDY. Particularly, Pd1Cu2@GDY exhibits superior FAD catalytic activity and hydrogen selectivity, presenting a potential novel formic acid dehydrogenation catalyst. Electronic structure analysis indicates that the band center difference Δε (Δε = εd - εp) serves as an assessment descriptor for formic acid dehydrogenation activity. Microkinetic analysis further confirms the performance of TACs predicted by DFT results, and shows that all TACs have good H2 selectivity even at a high temperature.

Effects of ball milling on hydrochar for integrated adsorption and photocatalysis performance

In this study, hydrochar (HC) was firstly treated by ball milling for methylene blue (MB) removal through combined adsorption-photodegradation. The ball-milled bamboo hydrochar (BM-HC) exhibited a maximum adsorption capacity of 49.522 mg/g and a synergistic adsorption-photodegradation removal rate of 95.22% within 30 min, which was superior to those of pristine HC (20.530 mg/g, 79.47%). Compared with HC, BM-HC had smaller particle size, increased quantities of polyfuran rings, enhanced adsorption of visible light, which were favorable for the enhancement of adsorption capacity and photodegradation rate. The effect of the catalyst dosage, MB concentration, water matrix, pH, coexisting ions on MB photodegradation were examined. The possible synergistic adsorption and photodegradation mechanism of MB was illustrated. The foremost active specie in the synergistic removal of MB was h+. In addition, the possible degradation pathways of MB were proposed depending on the intermediates detected by Liquid chromatography-mass spectrometry (LC-MS), and the biotoxicity of MB and its intermediates was evaluated by Ecological Structure-Activity Relationship (ECOSAR) program. This work confirms that ball-milled hydrochar could be used as a potential catalyst for pollutants removal in water via synergistic adsorption and photocatalysis.

Nickel ferrite decorated noble metal containing nitrogen-doped carbon nanotubes as potential magnetic separable catalyst for dinitrotoluene hydrogenation

The 2,4-toluenediamine (TDA) is one of the most important chemicals in the polyurethane industry, produced by the catalytic hydrogenation of 2,4-dinitrotoluene (DNT). The development of novel catalysts that can be easily recovered from the reaction mixture is of paramount importance. In our work, a NiFe2O4/N-BCNT supported magnetic catalyst was prepared by a modified coprecipitation method. The catalyst support alone also showed activity in the synthesis of TDA. Platinum nanoparticles were deposited on the catalyst support surface by a fast, relatively simple, and efficient sonochemical method, resulting in a readily applicable catalytically active system. The prepared catalyst exhibited high activity in hydrogenation tests, which was proved by the exceptionally high DNT conversion (100% for 120 min at 333 K) and TDA yield (99%). Furthermore, the magnetic catalyst can be easily recovered from the reaction medium by the action of an external magnetic field, which can greatly reduce catalyst loss during separation.

Stable silver nanoparticles synthesis using Tabebuia aurea leaf extract for efficient water treatment: A sustainable approach to environmental remediation

Noble metal nanoparticles have garnered significant attention owing to their extensive utility across various domains. Among them, silver nanoparticles (SNP) deliver solutions to various environmental problems in the area of water treatment. SNP are conventionally fabricated using chemical methods with toxic chemicals. In this work, we used leaf extract of Tabebuia aurea to rapidly synthesize stable silver nanoparticles (TA-SNP). The analysis of the UV–vis spectrum revealed surface plasmon resonance at 438 nm which confirmed the formation of SNP. The SEM image showed the nanosized and spherical morphology of the TA-SNP with a mean size of 48.68 nm. XRD pattern of nanoparticles pertaining to (101) plane, ascertained the fcc crystal arrangement with 19.36 nm as crystallite diameter. DLS confirmed the colloidal stability with a zeta potential of −26.7 mV. The FTIR studies suggest that the presence of various functional moieties of the leaf extract is accountable for the formation and capping of nanoparticle synthesis. The efficiency of TA-SNP as a potential catalyst in the reduction of the Congo Red and Acid Blue 113 dye with NaBH4 was demonstrated with first-order kinetic constants of 0.2723 and 0.1335 min –1 respectively. Hence, the environmentally friendly and cost-effective synthesis method used for SNP in the present study holds promise for developing nanocatalysts aimed at effectively removing diverse dyes from wastewater, thereby contributing to environmental remediation.

Production of biodiesel from non-edible waste palm oil and sterculia foetida using microwave irradiation

Abstract The environmental damage stemming from traditional diesel begins during crude oil extraction and persists throughout its usage. The burning of fossil fuels has further deteriorate the environmental effect and added to global warming by emitting harmful substances. Moreover, the reduction of finite fossil fuel reserves due to widespread extraction has made the adoption of renewable resources essential. Given these considerations, biodiesel emerges as a highly promising alternative to conventional diesel due to its environmentally beneficial nature, renewable source, and economic feasibility. In this study, biodiesel was prepared by a microwave reactor in the presence of potassium methoxide using blended waste palm oil and sterculia foetida. The effects of raw materials characteristics on transesterification products were studied. The studied process parameters were methanol/oil ratio, microwave temperature, catalyst concentration, reaction time, and stirring speed. The optimal yield with 98.5% FAME content was obtained at a methanol/oil ratio of 60 vol. %, microwave temperature of 120 °C, catalyst concentration of 0.3 wt.%, and 3 min reaction time, and stirring speed of 500 rpm. The potassium methoxide was used to catalyse the transesterification process. The physicochemical properties and the fatty acid methyl ester composition were discussed thoroughly. The flash point of biodiesel, at 157.5°C, exceeds that of diesel fuel by more than two times. The cetane index is 59.5 which is higher than diesel (49.6). The biodiesel’s fuel properties conformed to the requirements of both ASTM D6751 and EN 14214. High biodiesel conversion and low sulphur content show that waste palm oil and sterculia foetida are sustainable and economical feedstocks that produce clean fuel to aid the feasibility of the energy transition of the global energy sector. In addition, the selection of synthesis approaches can be further explored for potential catalysts to ensure eco-green biodiesel’s sustainability with minimised.

Synthesis of La1-xSrxCoO3-δ and its catalytic oxidation of NO and its reaction path

The oxidation rate of NO to NO2 is a critical parameter in the removal of NOx within selective catalytic reduction (SCR) systems. LaCoO3-δ is a kind of potential catalyst to enhance the oxidation of NO to NO2, it may offers an economic and stable alternative to noble metal catalysts, particularly at elevated temperatures. This study aimed to enhance the catalytic efficiency of LaCoO3-δ through strontium (Sr) doping. La1-xSrxCoO3-δ (with varying x values of 0.1, 0.2, 0.3, 0.4) was synthesized using a sol-gel method. La1-xSrxCoO3-δ exhibited superior NO oxidation catalytic activity compared to LaCoO3-δ, with the most notable enhancement observed at x = 0.3 (84 % conversion). This improvement can be attributed to the substitution of La3+ with Sr2+, which induces lattice distortion and charge imbalance, thereby creating more oxygen vacancies that enhance the catalytic oxidation capability of La1-xSrxCoO3-δ. However, it's important to note that an excessive amount of Sr can result in the formation of SrCO3 deposits on the surface of La1-xSrxCoO3-δ, thereby diminishing its catalytic oxidation performance. The catalytic oxidation reaction behavior adhered most closely to the O2-adsorbed E-R model, the surface defects in La1-xSrxCoO3-δ playing a pivotal role in the catalytic reaction.

Performance evaluation of a modified axial flow water Lifting pump for small to medium irrigation in Nigeria.

Most irrigation pumps used in Nigeria are imported. Consequently, the challenges farmers faced in using these pumps include but not limited to the following; priming before operation, relatively low-capacity delivery at low head and high price which is often time not affordable by peasant farmers. The objective of this research was to develop an axial flow pump with locally sourced materials and affordable by farmers for small to medium scale irrigation in Nigeria. The design of the pump for the study was adopted from an existing and functioning axial pumping machine, developed by Agricultural Machinery and Mechatronics Department, Kasetsart University, Thailand. The pump was fabricated at the workshop of National Centre for Agricultural Mechanization (NCAM), Ilorin, Nigeria. Diesel fuel was used in powering the pump because of higher torque deliverable. The developed pump based on its capacity can be used to irrigate one hectare in one hour at 16.2 mm depth of water using 2000 rpm at 1m head and 9.6 mm depth of water using 1000 rpm at 3 m head. The maximum water discharge of 162 m3/h (45 l/s) was at 1m using a speed of 2000 rpm with water to fuel delivery of 124.29 l/s. The maximum water discharge of 162 m3/h (45 l/s) was at 1m using a speed of 2000 rpm with water to fuel delivery of 119.57m3/L. And the least water discharge of 59.30 m3/h (28 l/s) and water delivery per fuel was 41.0m3/L at 3 m head at 1000 rpm. Therefore, the developed pump operates best at lower head of 1m featuring a 3kW prime mover. The developed pump based on its capacity can be used to irrigate one hectare in one hour at 16.2 mm depth of water using 2000rpm at 1m head and 9.6 mm depth of water using 1000rpm at 3m head at a moisture content of 45% on a sand-loamy soil. Statistical analysis reveals relationships between pump speed, head, fuel consumption, and various performance indicators. The centrifugal pumps were found to produce lower discharge than axial flow pumps at different water heads evaluated. Comparative economic analysis demonstrates the pump's superiority over conventional centrifugal pumps in terms of water-fuel delivery efficiency and operational cost. This study introduced a locally modified axial flow pump as a practical, cost-effective, and efficient solution to irrigation challenges faced by small and medium-scale farmers in Nigeria. This pump has higher capacity delivery, spare parts are readily available at local market, it is appropriate for use where the irrigation head requirements are low and large volumes of water is required to be lifted at low pressure, it is appropriate where water can be lifted from rivers and canals and then directed to farmers' fields for irrigation. It is also applicable in rice farm flooding and flood drainage. This type of pump is good for flood (surface) irrigation system, which include furrow, border, basin irrigation and uncontrolled flooding in loamy and clay soils for rice production and sugarcane productions. The pump's adoption and economic viability positions it as a potential catalyst for increased food production, income, and food security in the country.

Effect of the Second-Shell Coordination Environment on the Performance of P-Block Metal Single-Atom Catalysts for the Electrosynthesis of Hydrogen Peroxide

Hydrogen peroxide (H2O2) is an important chemical with a diverse range of industrial applications in chemical synthesis and medical disinfection. The traditional anthraquinone oxidation process, with high energy consumption and complexity, is being replaced by cost-effective and environmentally friendly alternatives. In order to explore suitable catalysts for the electrocatalytic synthesis of H2O2, the stability of B,N-doped graphene loaded with various p-block metal (PM) single atoms (i.e., PM-NxBy: x and y represent the number of atoms of N and B, respectively) and the effects of different numbers and positions of B dopants in the second coordination shell on the catalytic performance were studied by density functional theory (DFT) calculations. The results show that Ga-N4B6 and Sb-N4B6 exhibit enhanced stability and 2e− oxygen reduction reaction (ORR) activity and selectivity. Their thermodynamic overpotential η values are 0.01 V, 0.03 V for Ga-N4B6’s two configurations and 0.02 V, 0 V for Sb-N4B6’s two configurations. Electronic structure calculations indicate that the PM single atom adsorbs OOH* intermediates and transfers electrons into them, resulting in the activation of the O-O bond, which facilitates the subsequent hydrogenation reaction. In summary, Sb-N4B6 and Ga-N4B6 exhibit extraordinary 2e− ORR performance, and their predicted activities are comparable to those of known outstanding catalysts (such as PtHg4 alloy). We propose effective strategies on how to enhance the 2e− ORR activities of carbon materials, elucidate the origin of the activity of potential catalysts, and provide insights for the design and development of electrocatalysts that can be used for H2O2 production.

Cu MOF-biocarbon functional catalysts as adsorbent for oxygen-linked carbon capture via thermo-catalytic pyrolysis: A low-carbon fuel synthesis strategy

Low-carbon fuel synthesis is encouraged as it is environmentally benign and aims to lessen the impact of global warming. This experimental investigation examines the synthesized Bombax ceiba oil (Bio-oil) based pyrolyzed oil utilizing Cu MOF-biocarbon catalysts (0.15 wt.%) via thermo-catalytic cracking and adsorption. The structural and thermal characteristics of the developed Cu MOF - biocarbon catalysts are investigated using Field Emission – Scanning Electron Microscopy/Energy Dispersive Spectroscopy (FE-SEM/EDAX), Attenuated Total Reflectance-Infrared Spectroscopy (ATR-IR), X-Ray Diffraction (XRD), Thermogravimetry-Differential Thermal Analysis (TG-DTA) and Brunauer-Emmett-Teller (BET). Following a thermo-catalytic reaction with a hot plate magnetic stirrer (600 rpm, 100 °C, and 1 h), the oily Cu MOF-biocarbon catalysts are separated from the pyrolyzed green fuel using high-speed centrifugation. The cracking and adsorption of the pyrolyzed green oil compounds are studied using 1H NMR, GC–MS, and thermal conductivity. The results indicate that alkane compounds increase from 3.25 to 6.70 % whereas oxygen incorporated compounds decrease from 96.75 to 93.30 % in the pyrolyzed oil. Furthermore, the GC–MS study shows that the separated oily catalysts adsorb 44.52 % of hydrocarbon (CH) and oxygen-linked (CHO) hydro-carbon compounds. Overall, the newly synthesized Cu MOF-biocarbon is considered as a potential functional catalyst for cracking and adsorption of alkane/oxygen bonded compounds (e.g., CH, CO etc.,), promoting the pyrolyzed oil as low-carbon fuel for better sustainable environment.

Torture and blessing: the impostor phenomenon among Spanish female executives

PurposeThis research explores the impostor phenomenon (IP) within the context of gender and leadership, aiming to transform impostor feelings into catalysts for leadership empowerment and positive career outcomes.Design/methodology/approachUtilizing grounded theory, this study conducts in-depth interviews with 34 female Spanish senior executives to analyze their experiences with IP.FindingsThe research reveals that top executive women are not only affected by IP but can also harness it to foster personal and professional growth. It identifies key strategies – such as self-reflection, effective communication and cultivating positive habits – that enable women to transform IP into a lever for enhancing their careers. This approach leads to a proposed virtuous cycle model that empowers women to overcome the negative impacts of IP and advance their leadership capabilities.Originality/valueThis study contributes to the literature on gender and leadership by offering insights into the gendered nuances of IP. By framing IP as a potential catalyst for growth rather than a barrier, the study provides practical tools for human resource (HR) departments to promote gender diversity at senior levels. It also advocates for HR practices to dismantle internal barriers to women’s career progression and address conscious and unconscious gender biases.

Novel bilayer 2D V2O5 as a potential catalyst for fast photodegradation of organic dyes

Two-dimensional (2D) materials have recently drawn interest in various applications due to their superior electronic properties, high specific surface area, and surface activity. However, studies on the catalytic properties of the 2D counterpart of V2O5 are scarce. In the present study, the catalytic properties of 2D V2O5 vis-à-vis bulk V2O5 for the degradation of methylene blue dye are discussed for the first time. The 2D V2O5 catalyst was synthesized using a modified chemical exfoliation technique. A massive increase in the electrochemically active surface area of 2D V2O5 by one order of magnitude greater than that of bulk V2O5 was observed in this study. Simultaneously, ~ 7 times increase in the optical absorption coefficient of 2D V2O5 significantly increases the number of photogenerated electrons involved in the catalytic performance. In addition, the surface activity of the 2D V2O5 catalyst is enhanced by generating surface oxygen vacancy defects. In the current study, we have achieved ~ 99% degradation of 16 ppm dye using the 2D V2O5 nanosheet catalysts under UV light exposure with a remarkable degradation rate constant of 2.31 min−1, which is an increase of the order of 102 from previous studies using V2O5 nanostructures and nanocomposites as catalysts. Since the enhanced photocatalytic activity emerged from the surface and optical properties of the catalyst, the current study shows great promise for the future application of 2D V2O5 in photo- and electrocatalysis.

Mixedness in conflict: The impact of Yugoslav wars on intermarriages in the Western Balkans

AbstractThis paper examines the phenomenon of intermarriages in the Western Balkans, shedding light on their intricate relationship with the region's tumultuous history, ethnic diversity, and socio‐political dynamics. Through a comprehensive exploration of interethnic unions across different areas, the study delves into how these marriages have historically served as symbols of coexistence and integration, particularly during the mid‐20th century, when they were encouraged by the newly‐formed states to unite the different nations living in them. However, the rise of ethno‐nationalism and the Yugoslav Wars significantly impacted these marital patterns, underscoring the complex interplay between politics, culture, and traditional norms. The paper highlights the decline in mixed marriages post‐war, persistent ethnic tensions, and varying dynamics in different locales, suggesting that comprehensive approaches are needed for sustainable peace and unity in the Western Balkans. Through this lens, intermarriages emerge not just as personal unions but as potent symbols and potential catalysts for broader societal transformations, albeit within a context of considerable challenges and the need for nuanced, multifaceted approaches to fostering lasting interethnic harmony.

The Catalytic Potential of Modified Clays: A Review

The need for innovative catalysts and catalytic support materials is continually growing due to demanding requirements, stricter environmental demands, and the ongoing development of new chemical processes. Since about 80% of all industrial processes involve catalysts, there is a continuing need to develop new catalyst materials and supports with suitable qualities to meet ongoing industrial demands. Not only must new catalysts have tailored properties, but they must also be suitable for large-scale production through environmentally friendly and cost-effective processes. Clay minerals, with their rich history in medicine and ceramics, are now emerging as potential catalysts. Their transformative potential is exemplified in applications such as hydrogenating the greenhouse gas CO2 into carbohydrate fuel, a crucial step in meeting the rising electrical demand. Moreover, advanced materials derived from clay minerals are proving their mettle in diverse photocatalytic reactions, from organic dye removal to pharmaceutical pollutant elimination and photocatalytic energy conversion through water splitting. Clay minerals in their natural state show a low catalytic activity, so to increase their reactivity, they must be activated. Depending on the requirements of a particular application, selecting an appropriate activation method for modifying a natural clay mineral is a critical consideration. Traditional clay mineral processing methods such as acid or alkaline treatment are used. Still, these have drawbacks such as high costs, long processing times, and the formation of hazardous by-products. Other activation processes, such as ultrasonication and mechanical activation routes, have been proposed to reduce the production of hazardous by-products. The main advantage of ultrasonication and microwave-assisted procedures is that they save time, whereas mechanochemical processing is simple and efficient. This short review focuses on modifying clay minerals using various new methods to create sophisticated and innovative new materials. Recent advances in catalytic reactions are specifically covered, including organic biogeochemical processes, photocatalytic processes, carbon nanotube synthesis, and energy conversion processes such as CO2 hydrogenation and dry reforming of methane.

Efficient screening and catalytic mechanism of TM@β-Te for nitrogen reduction reaction

At present, nitrogen reduction reaction (NRR) has become one critical method for NH3 production through the single-atom catalyst (SAC). A variety of TM@β-Te SACs, constructed by 28 transition metal (TM) atoms anchoring on monovacant β-Te substrate, are systematically investigated by using DFT calculations. An efficient “six-step” screening scheme is proposed to screen out potential NRR catalysts, during which the implicit and explicit solvent models are involved to evaluate competitive reactions of H2O and H+. The final selected (Ta, W)@β-Te catalysts have limiting potentials (UL) of −0.32 V and −0.37 V, respectively. Three intrinsic descriptors of φ (the ratio of number of valence electrons and electronegativity of TM atom), ΔG∗N(adsorption energy of a single N atom on the substrate) and ICOHP (Crystal orbital Hamiltonian integrals for TM-N bonds) are proposed and their correlations with UL are investigated to expound the catalytic activity and mechanism. The relationships of dN≡N ∼ φ, ΔG∗N2∼ φ, ΔG∗N∼ φ and ICOHP ∼ φ resemble “volcanoes”, where (Ta, W)@β-Te are located near the vertex as potential catalysts, which can be verified by scaling relationship of ICOHP and ΔG∗N. Moreover, the UL ∼ φ, UL ∼ ΔG∗Nand UL ∼ ICOHP can be used to determine the potential catalysts from rough catalyst screening to accurate determination of potential determining step (PDS) in catalytic reaction. The constant potential model is adopted to investigate the influences of electrode potentials on adsorption strength of NRR intermediates. This work is informative for the research of NRR process and catalyst design of monoalkenes, which offers an efficient and dependable approach for screening excellent NRR catalysts and revealing the origin of catalytic activity.

An innovative method to identify structural change through ion-molecule collision, making use of Time-Of-Flight measurements and SIMION simulations.

Structural change of ions induced by collision with a neutral has been studied in a guided ion beam tandem mass spectrometer, using Time-Of-Flight measurements and SIMION simulation. The exothermic catalytic isomerization of HOC+ to HCO+ is used to explore the new methodology. Isomerization is catalyzed via a proton transport mechanism through the interplay of a neutral molecule, the catalyst. Four different potential catalysts, Ne, D2, CH4, and C18O, were studied at different collision energies. SIMION simulation of the ion path and collision in the instrument leads to the highlight of a specific signature related to the catalytic isomerization in the time-of-flight spectra. This signature is used to identify the experimental conditions where isomerization takes place. Only C18O, at low collision energies, gives a clear signature of catalytic isomerization, and a quantitative estimate of the catalyzed isomerization cross-section and rate constant is derived. This new methodology is sensitive to clear presence of catalyzed isomerization and can be used in instruments designed for cross-section measurements, provided low collision energy is used and ion bunching is available.

Facile synthesis of MoSe2 embedded in La2O3 crystal for enhancing hydrogen evolution reaction

ABSTRACT Molybdenum diselenide (MoSe2) is a potential catalyst for the electrocatalytic hydrogen evolution reaction (HER). However, MoSe2 exhibits a high overpotential in HER due to its low density of active sites, which may limit its practical applicability. Tuning the assisted metal interaction is an effective method for altering the atomic structure and catalytic efficiency of transition metal catalysts. Herein, we report a simple hydrothermal process for synthesising hybrid MoSe2-La2O3 heterostructures for HER. The electrocatalytic HER of nanoflower MoSe2 was improved in the presence of a supported lanthanide-oxide interaction (La2O3), proving that La2O3 materials produce additional activity sites in the MoSe2 materials. The nanocomposite was drop-cast onto screen-printed carbon electrodes (SPCE) and showed reduced overpotential values compared to pristine MoSe2 and La2O3 materials. Across all ratios tested, the MoSe2-La2O3 (M-L2) nanocomposites with a molar ratio of 1:2 exhibit rapid charge transfer during HER performance, with a Tafel slope value of 66 mV/dec and an onsetpotential of 270 mV.

Screening of Pd-Co-Ni catalyst arrays by scanning electrochemical microscopy and characterization of the potential catalyst for formic acid oxidation

BackgroundAppropriate anodic catalyst is one of the key points in improving the performance of direct formic acid fuel cells (DFAFCs). This study utilizes the concept of a combination method to design and screen anodic catalysts for formic acid oxidation. MethodsThe tip generation-substrate collection (TG-SC) mode of scanning electrochemical microscopy (SECM) was employed to screen the Pd-Co-Ni ternary catalyst array for catalyzing formic acid oxidation. The potential catalyst was further characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Significant findingsThe composition ratios of the prepared Pd-Co-Ni ternary catalyst array matched the concentration ratios set by the precursor solution. SECM screening revealed that the optimal ratio for formic acid oxidation was the Pd2Co6Ni2 catalyst. The cyclic voltammograms and CO stripping voltammograms indicate that the Pd2Co6Ni2 electrode exhibits lower onset potentials for the oxidation of formic acid and its intermediates than the pure Pd electrode. Electrochemical impedance spectroscopy (EIS) confirms that the Pd2Co6Ni2 electrode possesses lower interfacial resistance than the Pd electrode, with its pseudo-inductive behavior at high potential aligning with the outcomes observed in cyclic voltammograms and CO stripping voltammograms.

A supported Ni2 dual-atoms site hollow urchin-like carbon catalyst for synergistic CO2 electroreduction

Dual-atoms catalysts (DACs), while inheriting the advantages of maximum atom utilization ratio and excellent selectivity of single-atom catalysts (SACs), can better enhance the catalytic activity through the synergy of adjacent atoms. Therefore, DACs are considered to be very potential catalysts for CO2 to CO conversion. Its catalytic activity is greatly influenced by the coordination environment and morphology. Here, hollow urchin-like NiNC catalysts (Ni-NC(HU)-x, x = 100, 50, 25, 0) were synthesized using urchin-like nickel particles as template. By adjusting the amount of additional nitrogen source, the percentage content of pyridinic-N was adjusted as well as further affecting the coordination environment. Among them, Ni-NC(HU)-50, which had the highest content of pyridinic-N, formed a dual-atoms coordination structure and had the best catalytic performance that the CO Faradaic efficiency (FECO) reached 97.2 % at −0.9 V vs. reversible hydrogen electrode (RHE) and sustained above 95 % within 50 h. In-situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) and density functional theory (DFT) calculations showed that Ni-NC(HU)-50 exhibited the best performance of CO2 reduction reaction (CO2RR) by lowering the *COOH formation free energy barrier and its favorable dual desorption mechanism of *COL and *COB.