Hollow-structured cobalt sulfide electrocatalyst for alkaline oxygen evolution reaction: Rational tuning of electronic structure using iron and fluorine dual-doping strategy.

Utilizing renewable electricity for water electrolysis offers a promising way for generating high-purity hydrogen gases while mitigating the emission of environmental pollutants. To realize the water electrolysis, it is necessary to develop highly active and precious metal-free electrocatalyst for oxygen evolution reaction (OER) which incurs significant overpotential due to its complicated four-electron transfer mechanism. Hence, we propose a facile preparation method for hollow-structured Fe and F dual-doped CoS nanosphere (Fe-CoS-F) as an efficient OER electrocatalyst.

First-principles study on the design of nickel based bimetallic catalysts for xylose to xylitol conversion.

A significant challenge for effective biomass utilization and upgrading is catalysis. This research paper focuses on the conversion of xylose into xylitol, a valuable chemical used in the pharmaceutical and food industries. The primary objective is to design more efficient and cost-effective catalysts for this conversion process.

Experimental and Numerical Study of Pd/Ta and PdCu/Ta Composites for Thermocatalytic Hydrogen Permeation.

The development of stable and durable hydrogen (H) separation technology is essential for the effective use of H energy. Thus, the use of H permeable membranes, made of palladium (Pd), has been extensively studied in the literature. However, Pd has considerable constraints in large-scale applications due to disadvantages such as very high cost and H embrittlement.

First-principles design of hetero CoM (M = 3d, 4d, 5d block metals) double-atom catalysts for oxygen evolution reaction under alkaline conditions.

As an extension of single-atom catalysts, the development of double-atom catalysts with high electrocatalytic activity for the oxygen evolution reaction (OER) is vital to facilitate hydrogen production and industrial applications. The CoM (M = 3d, 4d, 5d block metals) homo and double-atom catalysts supported on nitrogen-doped graphene (CoM/NG) were prepared for electrochemical water oxidation under alkaline conditions, and the electrocatalytic activity was studied through density functional theory (DFT) calculations. The hetero CoCu/NG double-atom catalyst indicated the highest OER activity with an onset potential of 0.

Conversion of cyclic xylose into xylitol on Ru, Pt, Pd, Ni, and Rh catalysts: a density functional theory study.

There is currently no theoretical study on the hydrogenation of xylose to xylitol on a catalyst's surface, limiting proper understanding of the reaction mechanisms and the design of effective catalysts. In this study, DFT techniques were used for the first time to investigate the mechanisms of xylose to xylitol conversion on five notable transition metal (TM) surfaces: Ru(0001), Pt(111), Pd(111), Rh(111), and Ni(111). Two transition state (TS) paths were investigated: TS Path A and TS Path B.

Facile one-step synthesis of Ru doped NiCoP nanoparticles as highly efficient electrocatalysts for oxygen evolution reaction.

Transition metal phosphides (TMPs) as ever-evolving electrocatalytic materials have attracted increasing attention in water splitting reactions owing to their cost-effective, highly active and stable catalytic properties. This work presents a facile synthetic route to NiCoP nanoparticles with Ru dopants which function as highly efficient electrocatalysts for oxygen evolution reaction (OER) in alkaline media. The Ru dopants induced a high content of Ni and Co vacancies in NiCoP nanoparticles, and the more defective Ru doped NiCoP phase than undoped NiCoP ones led to a greater number of catalytically active sites and improved electrical conductivity after undergoing electrochemical activation.

Conformation-modulated three-dimensional electrocatalysts for high-performance fuel cell electrodes.

Unsupported Pt electrocatalysts demonstrate excellent electrochemical stability when used in polymer electrolyte membrane fuel cells; however, their extreme thinness and low porosity result in insufficient surface area and high mass transfer resistance. Here, we introduce three-dimensionally (3D) customized, multiscale Pt nanoarchitectures (PtNAs) composed of dense and narrow (for sufficient active sites) and sparse (for improved mass transfer) nanoscale building blocks. The 3D-multiscale PtNA fabricated by ultrahigh-resolution nanotransfer printing exhibited excellent performance (45% enhanced maximum power density) and high durability (only 5% loss of surface area for 5000 cycles) compared to commercial Pt/C.

Hierarchically Assembled Cobalt Oxynitride Nanorods and N-Doped Carbon Nanofibers for Efficient Bifunctional Oxygen Electrocatalysis with Exceptional Regenerative Efficiency.

Oxygen-based electrocatalysis is an integral aspect of a clean and sustainable energy conversion/storage system. The development of economic bifunctional electrocatalysts with high activity and durability during reversible reactions remains a great challenge. The tailored porous structure and separately presented active sites for oxygen reduction and oxygen evolution reactions (ORR and OER) without mutual interference are most crucial for achieving desired bifunctional catalysts.

Hydrogen-Mediated Thin Pt Layer Formation on NiN Nanoparticles for the Oxygen Reduction Reaction.

A simple wet-chemical route for the preparation of core-shell-structured catalysts was developed to achieve high oxygen reduction reaction (ORR) activity with a low Pt loading amount. Nickel nitride (NiN) nanoparticles were used as earth-abundant metal-based cores to support thin Pt layers. To realize the site-selective formation of Pt layers on the NiN core, hydrogen molecules (H) were used as a mild reducing agent.

Structural Engineering of Ultrathin ReS on Hierarchically Architectured Graphene for Enhanced Oxygen Reduction.

Herein, binary heteronanosheets made of ultrathin ReS nanosheets and reduced graphene oxide (RGO) with either a two-dimensional (2D) "sheet-on-sheet" architecture (2D ReS/RGO) or a three-dimensional hierarchical structure (3D ReS/RGO) are constructed through rational structure-engineering strategies. In the resultant 3D ReS/RGO heteronanosheets, the ultrathin ReS nanosheets are bridged on the RGO surface through Re-O bonds in a vertically oriented manner, which endows the heteronanosheets with open frameworks and a hierarchical porous structure. In sharp contrast to the 2D ReS/RGO, the 3D ReS/RGO heteronanosheets are featured with abundant active sites and channels for efficient electrolyte ions transport.

Roles of noble metals (M = Ag, Au, Pd, Pt and Rh) on CeO in enhancing activity toward soot oxidation: Active oxygen species and DFT calculations.

The effects of noble metal (M = Ag, Au, Pd, Pt, and Rh) on CeO in enhancing the activity toward soot oxidation were studied through experimental methods and density functional theory (DFT) calculations. Each noble metal (3 mol.%) was supported on CeO (M/CeO) and the properties of the catalysts were verified by XRD, HRTEM, N physisorption, CO chemisorption, XPS, and H-TPR results.

Synergetic Structural Transformation of Pt Electrocatalyst into Advanced 3D Architectures for Hydrogen Fuel Cells.

A new direction for developing electrocatalysts for hydrogen fuel cell systems has emerged, based on the fabrication of 3D architectures. These new architectures include extended Pt surface building blocks, the strategic use of void spaces, and deliberate network connectivity along with tortuosity, as design components. Various strategies for synthesis now enable the functional and structural engineering of these electrocatalysts with appropriate electronic, ionic, and electrochemical features.

Electrocatalytic glycerol oxidation enabled by surface plasmon polariton-induced hot carriers in Kretschmann configuration.

Plasmonic hot carrier generation has attracted increasing attention due to its ability to convert light to electrical energy. The generation of plasmon-induced hot carriers can be achieved via Landau damping in the non-radiative decay process of the plasmonic excitation energy. Localized surface plasmons (LSPs) undergo both radiative and non-radiative decays, while surface plasmon polaritons (SPPs) dissipate only via the non-radiative decay.

Anomalous in situ Activation of Carbon-Supported NiP Nanoparticles for Oxygen Evolving Electrocatalysis in Alkaline Media.

Electrochemical water splitting is one of the most promising systems by which to store energy produced from sustainable sources, such as solar and wind energy. Designing robust and stable electrocatalysts is urgently needed because of the relatively sluggish kinetics of the anodic reaction, i.e.

A graphitic edge plane rich meso-porous carbon anode for alkaline water electrolysis.

There is growing interest in alkaline water electrolysis as a sustainable approach for producing hydrogen, but developing efficient and inexpensive catalysts for the oxygen evolution reaction, which can limit the operational efficiency of water electrolysis due to its considerable overpotential, is regarded as the most overriding challenge. Therefore, significant progress has been made in developing catalysts with transition metal and carbon materials as alternative catalysts. Here, we prepared cobalt containing carbon nanofibers via a facile route of electrospinning and pyrolysis, and metal leached carbon nanofibers were also prepared by subsequently leaching the metal.

Transition metal alloying effect on the phosphoric acid adsorption strength of Pt nanoparticles: an experimental and density functional theory study.

The effect of alloying with transition metals (Ni, Co, Fe) on the adsorption strength of phosphoric acid on Pt alloy surfaces was investigated using electrochemical analysis and first-principles calculations. Cyclic voltammograms of carbon-supported PtM/C (M = Ni, Co, and Fe) electrocatalysts in 0.1 M HClO with and without 0.

Effect of gold subsurface layer on the surface activity and segregation in Pt/Au/Pt3M (where M = 3d transition metals) alloy catalyst from first-principles.

The effect of a subsurface hetero layer (thin gold) on the activity and stability of Pt skin surface in Pt3M system (M = 3d transition metals) is investigated using the spin-polarized density functional theory calculation. First, we find that the heterometallic interaction between the Pt skin surface and the gold subsurface in Pt/Au/Pt3M system can significantly modify the electronic structure of the Pt skin surface. In particular, the local density of states projected onto the d states of Pt skin surface near the Fermi level is drastically decreased compared to the Pt/Pt/Pt3M case, leading to the reduction of the oxygen binding strength of the Pt skin surface.

P-modified and carbon shell coated Co nanoparticles for efficient alkaline oxygen reduction catalysis.

Described herein is the development of a novel Co-based oxygen electrode catalyst coupled with unique carbon structures. The present carbon shell coated Co nanoparticles of which the surface composites are modified by phosphorus incorporation, exhibit efficient oxygen reduction activities as well as oxygen evolving properties.

Mechanisms of enhanced sulfur tolerance on samarium (Sm)-doped cerium oxide (CeO2) from first principles.

The role of samarium (Sm) 4f states and Sm-perturbed O 2p states in determining the sulfur tolerance of Sm-doped CeO2 was elucidated by using the density functional theory (DFT) + U calculation. We find that the sulfur tolerance of Sm-doped CeO2 is closely related to the modification of O 2p states by the strong interaction between Sm 4f and O 2p states. In particular, the availability of unoccupied O 2p states near the Fermi level is responsible for enhancing the sulfur tolerance of Sm-doped CeO2 compared to the pure CeO2 by increasing the activity of the surface lattice oxygen toward sulfur adsorption, by weakening the interaction between Sm-O, and by increasing the migration tendency of the subsurface oxygen ion toward the surface.

Carbon dioxide conversion into hydrocarbon fuels on defective graphene-supported Cu nanoparticles from first principles.

Density functional theory studies demonstrate that defective graphene-supported Cu nanoparticles can modify the structural and electronic properties of copper for enhancing electrochemical reduction of carbon dioxide (CO2) into hydrocarbon fuels (CH4, CO, and HCOOH). We not only provide improved understanding of CO2 conversion mechanisms on both Cu and the Cu nanoparticle system, but also explain a key factor for enhanced CO2 conversion. A promising catalytic material for CO2 conversion into hydrocarbon fuels may allow for geometry flexibility upon interaction with a key intermediate of CHO*.

Edge-exposed MoS2 nano-assembled structures as efficient electrocatalysts for hydrogen evolution reaction.

Edge-exposed MoS2 nano-assembled structures are designed for high hydrogen evolution reaction activity and long term stability. The number of sulfur edge sites of nano-assembled spheres and sheets is confirmed by Raman spectroscopy and EXAFS analysis. By controlling the MoS2 morphology with the formation of nano-assembled spheres with the assembly of small-size fragments of MoS2, the resulting assembled spheres have high electrocatalytic HER activity and high thermodynamic stability.

Communication: Enhanced oxygen reduction reaction and its underlying mechanism in Pd-Ir-Co trimetallic alloys.

Based on a combined density functional theory and experimental study, we present that the electrochemical activity of Pd3Co alloy catalysts toward oxygen reduction reaction (ORR) can be enhanced by adding a small amount of Ir. While Ir tends to favorably exist in the subsurface layers, the underlying Ir atoms are found to cause a substantial modification in the surface electronic structure. As a consequence, we find that the activation barriers of O/OH hydrogenation reactions are noticeably lowered, which would be mainly responsible for the enhanced ORR activity.