Catalysts For Hydrogen Evolution Research Articles

Ruthenium Nanoclusters and Single Atoms on α-MoC/N-Doped Carbon Achieves Low-input/Input-free Hydrogen Evolution via Decoupled/Coupled Hydrazine Oxidation.

The hydrazine oxidation-assisted H2 evolution method promises low-input and input-free hydrogen production. However, developing high-performance catalysts for hydrazine oxidation (HzOR) and hydrogen evolution (HER) is challenging. Here, we introduce a bifunctional electrocatalyst α-MoC/N-C/RuNSA, merging ruthenium (Ru) nanoclusters (NCs) and single atoms (SA) into cubic α-MoC nanoparticles-decorated N-doped carbon (α-MoC/N-C) nanowires, through electrodeposition. The composite showcases exceptional activity for both HzOR and HER, requiring -80 mV and -9 mV respectively to reach 10 mA cm-2. Theoretical and experimental insights confirm the importance of two Ru species for bifunctionality: NCs enhance the conductivity, and its coexistence with SA balances the H adsorption for HER and facilitates the initial dehydrogenation during the HzOR. In the overall hydrazine splitting (OHzS) system, α-MoC/N-C/RuNSA excels as both anode and cathode materials, achieving 10 mA cm-2 at just 64 mV. The zinc hydrazine (Zn-Hz) battery assembled with α-MoC/N-C/RuNSA cathode and Zn foil anode can exhibit 96% energy efficiency, as well as temporary separation of hydrogen gas during the discharge process. Therefore, integrating Zn-Hz with OHzS system enables self-powered H2 evolution, even in hydrazine sewage. Overall, the amalgamation of NCs with SA achieves diverse catalytic activities for yielding multifold hydrogen gas through advanced cell-integrated-electrolyzer system.

Ruthenium Nanoclusters and Single Atoms on α‐MoC/N‐Doped Carbon Achieves Low‐input/Input‐free Hydrogen Evolution via Decoupled/Coupled Hydrazine Oxidation

The hydrazine oxidation‐assisted H2 evolution method promises low‐input and input‐free hydrogen production. However, developing high‐performance catalysts for hydrazine oxidation (HzOR) and hydrogen evolution (HER) is challenging. Here, we introduce a bifunctional electrocatalyst α‐MoC/N‐C/RuNSA, merging ruthenium (Ru) nanoclusters (NCs) and single atoms (SA) into cubic α‐MoC nanoparticles‐decorated N‐doped carbon (α‐MoC/N‐C) nanowires, through electrodeposition. The composite showcases exceptional activity for both HzOR and HER, requiring ‐80 mV and ‐9 mV respectively to reach 10 mA cm‐2. Theoretical and experimental insights confirm the importance of two Ru species for bifunctionality: NCs enhance the conductivity, and its coexistence with SA balances the H adsorption for HER and facilitates the initial dehydrogenation during the HzOR. In the overall hydrazine splitting (OHzS) system, α‐MoC/N‐C/RuNSA excels as both anode and cathode materials, achieving 10 mA cm‐2 at just 64 mV. The zinc hydrazine (Zn‐Hz) battery assembled with α‐MoC/N‐C/RuNSA cathode and Zn foil anode can exhibit 96% energy efficiency, as well as temporary separation of hydrogen gas during the discharge process. Therefore, integrating Zn‐Hz with OHzS system enables self‐powered H2 evolution, even in hydrazine sewage. Overall, the amalgamation of NCs with SA achieves diverse catalytic activities for yielding multifold hydrogen gas through advanced cell‐integrated‐electrolyzer system.

Nickel Nanoparticles Supported on P-Doped Tungsten Nitride Nanosheets as Catalysts for Hydrogen Evolution

Nickel Nanoparticles Supported on P-Doped Tungsten Nitride Nanosheets as Catalysts for Hydrogen Evolution

Integration of biocompatible hydrogen evolution catalyst developed from metal-mix solutions with microbial electrosynthesis

Microbial conversion of CO2 to multi-carbon compounds such as acetate and butyrate is a promising valorisation technique. For those reactions, the electrochemical supply of hydrogen to the biocatalyst is a viable approach. Earlier we have shown that trace metals from microbial growth media spontaneously form in situ electro-catalysts for hydrogen evolution. Here, we show biocompatibility with the successful integration of such metal mix-based HER catalyst for immediate start-up of microbial acetogenesis (CO2 to acetate). Also, n-butyrate formation started fast (after twenty days). Hydrogen was always produced in excess, although productivity decreased over the 36 to 50 days, possibly due to metal leaching from the cathode. The HER catalyst boosted microbial productivity in a two-step microbial community bioprocess: acetogenesis by a BRH-c20a strain and acetate elongation to n-butyrate by Clostridium sensu stricto 12 (related) species. These findings provide new routes to integrate electro-catalysts and micro-organisms showing respectively bio and electrochemical compatibility.

Theoretical study of electrochemical hydrogen evolution reaction of Pt–Co diatomic sites catalyst

Hydrolytic Hydrogen is a clean hydrogen production method. To mitigate the substantial costs associated with water electrolysis, electrocatalysts are crucial in decreasing the cathodic reaction involved in hydrogen hydrolysis, specifically, the overpotential for hydrogen evolution reaction (HER). Compared to traditional catalysts and single-atom catalysts, Pt–Co diatomic sites catalyst exhibit excellent hydrogen evolution reaction activity and stability. We have established eight different structures of dual-center metal catalysts based on graphene planes. A systematic study was conducted on the catalytic performance and mechanism of these configurations, among which the structure with the best hydrogen evolution reaction activity was CoN4/PtC2N2, with a Gibbs free energy (ΔG) of 0.004 eV. Electronic structure analysis confirms that H follows the Sabatier mechanism on diatomic catalysts, and the catalyst exhibits excellent HER performance for moderate adsorption strength of H atoms. The d-band centers of Co and Pt atoms in the electrocatalyst CoN4–PtC2N2 are lower than those of a single system, indicating that the electronic effect between the CoN4 and PtC2N2 sites can enhance the inherent HER activity of the catalyst. This study expands the application scope of dual-site catalysts and provides new insights for the design and synthesis of dual-site hydrogen evolution catalysts.

Silk derived electrospun carbon nanofibers loaded with CoS nanoparticles as efficient hydrogen evolution reaction catalysts in acidic and alkaline media

The design of a stable and efficient hydrogen evolution catalyst across the entire pH range is of significant importance for the development of hydrogen production technology by electrocatalytic water splitting. This study chose biomass silk fibroin protein as the electrospinning raw material, synthesizing a hybrid membrane of CoS@carbon nanofibers (CNF) with a layered core–shell structure through simple carbonization and hydrothermal treatment. The CoS nanoparticles can grow uniformly and densely on the CNF. By varying the concentrations of hexahydrate cobalt nitrate (Co(NO3)2·6H2O) and thiourea (CH4N2S), the morphology of the synthesized CoS nanoparticles on CNF can be controlled. Different microscopic morphologies lead to differences in the activity of the hydrogen evolution reaction (HER), attributed to variations in the exposed active sites for different morphologies. Compared to pure CNF, the CoS-2@CNF hybrid membrane exhibits excellent HER activity in both acidic and alkaline electrolytes. This highlights the synergistic catalytic effect between CNF and CoS particles. This work provides guidance for the rational design of bio-based catalysts with excellent performance.

Construction of P-doped high efficiency hydrogen evolution catalyst

Transition metal hydrogen evolution catalysts have attracted much attention. Here, we prepared a high-efficiency HER electrocatalyst based on nickel foam by constant current electrodeposition. Based on Mo and Co elements, the ternary catalyst was prepared by adding P, and the synthesized CoMoP-NF catalyst showed a remarkable effect in alkaline electrolytes. The overpotential of the CoMoP-NF catalyst is 35.1 mV at a current density of −10 mA cm−2 and 71 mV at −20 mA cm−2. The composition and structure of the catalyst were studied by SEM, XRD, XPS and TEM. And the stability of the CoMoP-NF catalyst with the best catalytic performance was tested for 12 hours, there is only a tiny increase in overpotential, indicating that the catalyst had excellent stability. This work has a certain impact on the preparation of efficient hydrogen evolution catalyst.

Precious Metal Free Hydrogen Evolution Catalyst Design and Application.

The quest to identify precious metal free hydrogen evolution reaction catalysts has received unprecedented attention in the past decade. In this Review, we focus our attention to recent developments in precious metal free hydrogen evolution reactions in acidic and alkaline electrolyte owing to their relevance to commercial and near-commercial low-temperature electrolyzers. We provide a detailed review and critical analysis of catalyst activity and stability performance measurements and metrics commonly deployed in the literature, as well as review best practices for experimental measurements (both in half-cell three-electrode configurations and in two-electrode device testing). In particular, we discuss the transition from laboratory-scale hydrogen evolution reaction (HER) catalyst measurements to those in single cells, which is a critical aspect crucial for scaling up from laboratory to industrial settings but often overlooked. Furthermore, we review the numerous catalyst design strategies deployed across the precious metal free HER literature. Subsequently, we showcase some of the most commonly investigated families of precious metal free HER catalysts; molybdenum disulfide-based, transition metal phosphides, and transition metal carbides for acidic electrolyte; nickel molybdenum and transition metal phosphides for alkaline. This includes a comprehensive analysis comparing the HER activity between several families of materials highlighting the recent stagnation with regards to enhancing the intrinsic activity of precious metal free hydrogen evolution reaction catalysts. Finally, we summarize future directions and provide recommendations for the field in this area of electrocatalysis.

Investigating the potential use of Ni-Mn-Co (NMC) battery materials as electrocatalysts for electrochemical water splitting.

The imminent generation of significant amounts of Li ion battery waste is of concern due to potential detrimental environmental impacts. However, this also poses an opportunity to recycle valuable battery materials for later use. One underexplored area is using commonly employed cathode materials such as nickel, manganese cobalt (NMC) oxide as an electrocatalyst for water splitting reactions. In this work we explore the possibility of using NMC materials of different metallic ratios (NMC 622 and 811) as oxygen evolution and hydrogen evolution catalysts under alkaline conditions. We show that both materials are excellent oxygen evolution reaction (OER) electrocatalysts but perform poorly for the hydrogen evolution reaction. NMC 622 demonstrates the better OER activity with an overpotential of only 280 mV to pass 100 mA cm-2 and a low tafel slope of 42 mV dec-1. The material can also pass high current densities of 150 mA cm-2 for 24 h while also being tolerant to extensive potential cycling indicating suitability for direct integration with renewable energy inputs. This work demonstrates that NMC cathode materials if recovered from Li ion batteries are suitable OER electrocatalysts.

From Co-MOF to Co@carbon–comparison of needle-like catalysts in photo-driven hydrogen evolution

In response to the rising demand for catalytic hydrogen production, more attention is focused on noble-metal-free catalysts such as cobalt-based metal–organic frameworks (MOFs) and their derivatives. Due to the varying activity of cobalt forms in photocatalytic processes, the present study explores the performance of photo-driven hydrogen generation of cobalt nitrilotriacetate (Co-NTA) with metal ions and MOF-derived carbons containing Co/CoOx/CoNx. The needle-like morphology of the obtained Co-NTA template was preserved in carbon materials prepared through carbonization with and without furfuryl alcohol. Carbons featured nitrogen-containing graphitic structures and oxygen functional groups. They were also characterized by a more developed specific surface area and larger pore volume compared to their parent MOF. All materials evolved hydrogen under visible light in a photosensitized system. Owing to the high content of metallic cobalt on the surface of non-impregnated carbon, it produced three times more hydrogen (14.2 mmol g−1) than Co-NTA.

NiFeCo-based high entropy alloys nanoparticles coated with N-doped graphene layers as hydrogen evolution catalyst in alkaline solution

Electrochemical water splitting is an environmentally friendly technology for producing hydrogen energy. Recent studies have shown that high entropy alloys (HEAs) and N-doped graphene layers coated alloys have superior hydrogen evolution reaction (HER) performance compared to traditional alloys. This paper presents a simple method for synthesizing N-doped graphene layers coated HEAs with controllable thickness. NiFeCo-based alloy materials are prepared using this method and used as HER catalysts in alkaline conditions. Experimental results and density functional theory (DFT) calculations demonstrate that the CuNiFeCoCrTi@N-doped graphene nanoparticles (CuNiFeCoCrTi@NC NPs) with a graphene shell of 2–3 layers exhibit the best hydrogen evolution performance. The improvement of hydrogen evolution performance should be related to the unique properties of HEAs and coating the surface of alloys with thin graphene shell. This study presents a simple and efficient method for synthesizing HEA@NC NPs, which can be used as an efficient electrocatalyst in alkaline water splitting systems.

N-Doped FeP4 Nanoparticles on Carbon Cloth as Catalysts for Electrolytic Hydrogen Evolution

N-Doped FeP₄ Nanoparticles on Carbon Cloth as Catalysts for Electrolytic Hydrogen Evolution

Phase engineering and N doping modulated MoSe2 nanosheets for large-current–density hydrogen evolution in simulated seawater

Molybdenum selenide (MoSe2) is considered to be a promising catalyst for seawater hydrogen evolution, but its catalytic activity falls far short of requirements due to its inert surface. Here, self-supported N-doped 1 T@2H-MoSe2/N doped carbon paper (N-MoSe2/NCP) was fabricated by a novel low-temperature nitrogen plasma strategy. In alkaline simulated seawater, the optimized N-MoSe2/NCP-30 only requires an overpotential of 274 mV to reach −200 mA cm−2 with Tafel slope of 54.7 mV dec-1, and exhibits stability over 24 h. This work proposes that the introduction of 1 T phase and N dopant into 2H-MoSe2 using low-temperature plasma strategy can significantly facilitate the exposure of abundant active edge sites and boost the conductivity of MoSe2.

ZnMo-MOF as anti-CO hydrogen electrocatalyst enhance microbial electrosynthesis for CO/CO2 conversion

Microbial electrosynthesis (MES) is an electrically driven technology that can be used for converting CO/CO2 into chemicals. The unique electronic and substrate properties of CO make it an important research target for MES. However, CO can poison the cathode and increase the overpotential of hydrogen evolution reaction (HER), thus reducing the electron transfer rate via H2. This work evaluated the effect of an anti-CO HER catalyst on the performance of MES for CO/CO2 conversion. ZnMo-metal–organic framework (MOF) materials with different calcination temperatures were synthesized. ZnMo-MOF-800 with Mo2C nanoparticles as active centers exhibited excellent resistance to CO toxicity. It also obtained the highest hydrogen evolution and enhanced electron transfer rate in CO atmosphere. MES with ZnMo-MOF-800 cathode and Clostridium ljungdahlii as biocatalyst obtained 0.31 g L−1 d−1 acetate yield, 0.1 g L−1 d−1 butyrate yield, and 0.09 g L−1 d−1 2,3-butanediol yield in CO/CO2, while Pt/C only get 0.076 g L−1 d−1 acetate yield, 0.05 g L−1 d−1 butyrate yield and 0.02 g L−1 d−1 2,3-butanediol yield. ZnMo-MOF-800 was conducive to biofilm formation, enabling it to better resist CO toxicity. This work provides new opportunities for constructing a highly efficient cathode with an anti-CO hydrogen evolution catalyst to enhance CO/CO2 conversion in MES.

Intercalated PtCo Electrocatalyst of Vanadium Metal Oxide Increases Charge Density to Facilitate Hydrogen Evolution.

Efforts to develop high-performance electrocatalysts for the hydrogen evolution reaction (HER) are of utmost importance in ensuring sustainable hydrogen production. The controllable fabrication of inexpensive, durable, and high-efficient HER catalysts still remains a great challenge. Herein, we introduce a universal strategy aiming to achieve rapid synthesis of highly active hydrogen evolution catalysts using a controllable hydrogen insertion method and solvothermal process. Hydrogen vanadium bronze HxV2O5 was obtained through controlling the ethanol reaction rate in the oxidization process of hydrogen peroxide. Subsequently, the intermetallic PtCoVO supported on two-dimensional graphitic carbon nitride (g-C3N4) nanosheets was prepared by a solvothermal method at the oil/water interface. In terms of HER performance, PtCoVO/g-C3N4 demonstrates superior characteristics compared to PtCo/g-C3N4 and PtCoV/g-C3N4. This superiority can be attributed to the notable influence of oxygen vacancies in HxV2O5 on the electrical properties of the catalyst. By adjusting the relative proportions of metal atoms in the PtCoVO/g-C3N4 nanomaterials, the PtCoVO/g-C3N4 nanocomposites show significant HER overpotential of η10 = 92 mV, a Tafel slope of 65.21 mV dec-1, and outstanding stability (a continuous test lasting 48 h). The nanoarchitecture of a g-C3N4-supported PtCoVO nanoalloy catalyst exhibits exceptional resistance to nanoparticle migration and corrosion, owing to the strong interaction between the metal nanoparticles and the g-C3N4 support. Pt, Co, and V simultaneous doping has been shown by Density Functional Theory (DFT) calculations to enhance the density of states (DOS) at the Fermi level. This augmentation leads to a higher charge density and a reduction in the adsorption energy of intermediates.

High-Performance MoP-Mo2C/C Heterogeneous Nanoparticle Catalysts for Alkaline Hydrogen Evolution and Oxidation Reactions

High-Performance MoP-Mo₂C/C Heterogeneous Nanoparticle Catalysts for Alkaline Hydrogen Evolution and Oxidation Reactions

Rational design of covalent organic frameworks/NaTaO3 S-scheme heterostructure for enhanced photocatalytic hydrogen evolution

As a typical perovskite material, NaTaO3 has been regarded as a potential catalyst for photocatalytic hydrogen evolution (PHE) process, due to its excellent photoelectric property and superior chemical stability. However, the photocatalytic activity of pure NaTaO3 was largely restricted by its poor visible-light absorption ability and rapid recombination of photogenerated charge carriers. Therefore, a covalently bonded TpBpy covalent organic framework (COF)/NaTaO3 (TpBpy/NaTaO3) heterostructure was designed and synthesized by the post modification strategy with (3-aminopropyl) triethoxysilane (APTES) and the in situ solvothermal process. Benefiting from the enhanced built-in electric field by the interfacial covalent bonds and the formation of S-scheme heterostructure between TpBpy and NaTaO3, which were proved by the Ar+-cluster depth profile and X-ray photoelectron spectroscopy (XPS), as well as density functional theory (DFT) calculation results, both the charge transfer efficiency and the PHE performance of the TpBpy/NaTaO3 composites were significantly improved. Additionally, the composites exhibited an excellent absorption performance in the visible region, which was also beneficial for the photocatalytic process. As expected, the optimal TpBpy/20%NaTaO3 composite achieved a remarkable hydrogen evolution rate of 17.3 mmol·g−1·h−1 (10 mg of catalyst) under simulated sunlight irradiation, which was about 173 and 2.4 times higher than that of pure NaTaO3 and TpBpy, respectively. This work provided a novel strategy for constructing highly effective and stable semiconductor/COFs heterostructures with strong interfacial interaction for photocatalytic hydrogen evolution.

Cysteamine Chemisorption at Mercury-Solution Interfaces in the Context of Redox and Microdissociation Equilibria.

The redox behavior and chemisorption of cysteamine (CA) at a charged mercury surface are described, with an emphasis on its acid-base properties supported by molecular dynamics and quantum mechanical calculations. It was found that CA forms chemisorbed layers on the surface of the mercury electrode. The formation of Hg-CA complexes is connected to mercury disproportionation, as reflected in peaks SII and SI at potentials higher than the electrode potential of zero charge (p.z.c.). Both the process of chemisorption of CA and its consequent redox transformation are proton-dependent. Also, depending on the protonation of CA, the formation of typical populations of chemisorbed conformers can be observed. In addition, cystamine (CA disulfide dimer) can be reduced on the mercury surface. Between the potentials of this reduction and peak SI, the p.z.c. of the electrode used can be found. Furthermore, CA can serve as an LMW catalyst for hydrogen evolution. The mechanistic insights presented here can be used for follow-up research on CA chemisorption and targeted modification of other metallic surfaces.

CoFe-Layered Double Hydroxide Needles on MoS2/Ni3S2 Nanoarrays for Applications as Catalysts for Hydrogen Evolution and Oxidation of Organic Chemicals

CoFe-Layered Double Hydroxide Needles on MoS₂/Ni₃S₂ Nanoarrays for Applications as Catalysts for Hydrogen Evolution and Oxidation of Organic Chemicals

A general strategy for the enhanced H2 production performance of CdS/noble metal sulfide nanorods photocatalysts by cation exchange

In this work, we report a series of noble metal (Ag, Au, Pt, etc.) sulfides that act as co-catalysts anchoring on CdS nanorods (NRs) obtained via a cation exchange strategy to promote photocatalytic hydrogen evolution. CdS NRs are first generated via a hydrothermal routine, noble metal sulfides are then in-situ grown on CdS NRs by a cation exchange method. CdS/Ag2S, CdS/Au2S and CdS/PtS NRs show improved hydrogen production rates (2506.88, 1513.17 and 1004.54 μmol g−1h−1, respectively), approximately 18, 11 and 7 times higher than CdS NRs (138.27 μmol g−1h−1). Among CdS/noble metal sulfide NRs, CdS/Ag2S NRs present the best H2 production performance. The apparent quantum efficiency (AQE) of CdS/Ag2S NRs achieves 3.11 % at λ = 370 nm. The improved photocatalytic performance of CdS/noble metal sulfide NRs dues to the following points: i) Noble metal sulfides on CdS NRs are beneficial for elevating light-absorbing and light-utilizing capacities, contributing to generating more photoexcited charges; ii) Noble metal sulfides are in-situ grown on CdS NRs as electron acceptors by a cation exchange method, thus the photoexcited electrons generated by CdS NRs rapidly migrate to the surface of noble metal sulfides, successfully accelerating the carriers separation efficiency. This series of noble metal sulfides acting as co-catalysts anchoring on CdS NRs offer new insights into the construction principles of high-performance photocatalytic hydrogen evolution catalysts.