Increased activity in hydrogen evolution electrocatalysis for partial anionic substitution in cobalt oxysulfide nanoparticles

2016 ◽  
Vol 4 (8) ◽  
pp. 2842-2848 ◽  
Author(s):  
Andrew Nelson ◽  
Kevin E. Fritz ◽  
Shreyas Honrao ◽  
Richard G. Hennig ◽  
Richard D. Robinson ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Anion Exchange ◽  
Hydrogen Evolution Reaction ◽  
Adsorption Energy ◽  
Increased Activity

Metastable CoOxSy electrocatalysts for the hydrogen evolution reaction were prepared by anion exchange. Lightly doped CoOxS0.18 is 2–3 times more active than either end-member of the substitution series due to optimized H adsorption energy.

Flower-like tungsten-doped Fe–Co phosphides as efficient electrocatalysts for hydrogen evolution reaction

CrystEngComm ◽  
2021 ◽  
Author(s):  
Qian Zhang ◽  
Shuihua Tang ◽  
Lieha Shen ◽  
Weixiang Yang ◽  
Zhen Tang ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Adsorption Energy ◽  
High Performance ◽  
Hydrogen Adsorption ◽  
Cost Effective

Developing cost-effective and high-performance electrocatalysts for hydrogen evolution reaction (HER) are imperative thanks to rapid increase of fuel-cell driven vehicles. Tungsten (W) possesses advantages of optimized hydrogen adsorption energy and...

Anion-exchange synthesis of nanoporous FeP nanosheets as electrocatalysts for hydrogen evolution reaction

2013 ◽  
Vol 49 (59) ◽  
pp. 6656 ◽  
Author(s):  
You Xu ◽  
Rui Wu ◽  
Jingfang Zhang ◽  
Yanmei Shi ◽  
Bin Zhang
Keyword(s):  
Hydrogen Evolution ◽  
Anion Exchange ◽  
Hydrogen Evolution Reaction

Polarisation cathodique en milieu alcalin des alliages Nb–Co

1981 ◽  
Vol 59 (8) ◽  
pp. 1261-1266 ◽  
Author(s):  
Y. Umetsu ◽  
D. L. Piron ◽  
G. Bélanger
Keyword(s):  
Solid Solution ◽  
Optical Microscopy ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Cathodic Polarization ◽  
Electrochemical Activity ◽  
Surface Degradation ◽  
Δ Phase ◽  
The One ◽  
Increased Activity

NbCo alloys were prepared and their composition characterized by optical microscopy. These alloys were evaluated for their electrochemical activity towards the hydrogen evolution reaction (HER) at 25 °C in a 25% KOH solution. The alloys between 20 and 70wt% Co showed an increased activity compared to their parent metals. However the activity is below the one observed for pure Ni. As for the NbNi alloys, the NbCo undergo some surface degradation under prolonged (6 h) cathodic polarization at 400–700 mA cm−2. This disintegration of the surfaces is observed for alloys below 50% in Co. Above this proportion, the alloys remain stable towards the RDH. This degradation is associated with the presence of the δ phase in the alloy: this phase is the solid solution of Nb in the alloy.

scholarly journals Insights into Hydrogen Evolution Reaction on 2D Transition Metal Dichalcogenides

2021 ◽  
Author(s):  
Zhenbin Wang ◽  
Michael Tang ◽  
Ang Cao ◽  
Karen Chan ◽  
Jens Kehlet Nørskov
Keyword(s):  
Transition Metal ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Adsorption Energy ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Activation Barrier ◽  
Transition Metal Dichalcogenides ◽  
Adsorbed Hydrogen ◽  
Metal Dichalcogenides

<p>Understanding the hydrogen evolution reaction (HER) behaviors over 2D transition metal dichalcogenides (2D-TMDs) is critical for the development of non-precious HER electrocatalysts with better activity. In this work, by combining density functional theory calculations with microkinetic modelling, we thoroughly investigated the HER mechanism on 2D-TMDs. We find there is an important dependence of simulated cell size on the calculated hydrogen adsorption energy and the activation barrier for MoS<sub>2</sub>. Distinct from previous “H migration” mechanisms proposed for the Heyrovsky reaction − the rate-determining step for MoS<sub>2</sub>, we propose the Mo site only serves as the stabilized transition state rather than H adsorption. In comparison to transition metal electrocatalysts, we find that the activation barrier of the Heyrovsky reaction on 2D-TMDs scales with the hydrogen adsorption energy exactly as for transition metals except that all activation energies are displaced upwards by <i>ca.</i> 0.4 eV. This higher Heyrovsky activation barrier is responsible for the substantially lower activity of 2D-TMDs. We further show that this higher activation barrier stems from the more positively charged adsorbed hydrogen on the chalcogenides interacting repulsively with the incoming proton. Based on these insights, we discuss potential strategies for the design of non-precious HER catalysts with activity comparable to Pt.</p>

scholarly journals [NiFe]-(Oxy)Sulfides Derived from NiFe2O4 for the Alkaline Hydrogen Evolution Reaction

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 543
Author(s):  
David Tetzlaff ◽  
Vasanth Alagarasan ◽  
Christopher Simon ◽  
Daniel Siegmund ◽  
Kai junge Puring ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Hydrogen Generation ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Precise Control ◽  
Metal Free ◽  
Synthetic Procedure ◽  
Key Factor ◽  
Increased Activity

The development of noble-metal-free electrocatalysts is regarded as a key factor for realizing industrial-scale hydrogen production powered by renewable energy sources. Inspired by nature, which uses Fe- and Ni-containing enzymes for efficient hydrogen generation, Fe/Ni-containing chalcogenides, such as oxides and sulfides, received increasing attention as promising electrocatalysts to produce hydrogen. We herein present a novel synthetic procedure for mixed Fe/Ni (oxy)sulfide materials by the controlled (partial) sulfidation of NiFe2O4 (NFO) nanoparticles in H2S-containing atmospheres. The variation in H2S concentration and the temperature allows for a precise control of stoichiometry and phase composition. The obtained sulfidized materials (NFS) catalyze the hydrogen evolution reaction (HER) with increased activity in comparison to NFO, up to −10 and −100 mA cm−2 at an overpotential of approx. 250 and 450 mV, respectively.

Carbon impurity-free, novel Mn,N co-doped porous Mo2C nanorods for an efficient and stable hydrogen evolution reaction

2019 ◽  
Vol 6 (9) ◽  
pp. 2464-2471 ◽  
Author(s):  
Yajun Zhou ◽  
Jieyu Xu ◽  
Cheng Lian ◽  
Lin Ge ◽  
Lingxia Zhang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Adsorption Energy ◽  
Hydrogen Adsorption ◽  
Carbon Impurity ◽  
Co Doped

Carbon impurity-free, novel Mn,N co-doped porous Mo2C nanorods reduce the hydrogen adsorption energy, functioning as efficient HER electrocatalysts.

Superhydrophilic nickel cyclotetraphosphate for hydrogen evolution reaction in acidic solution

2021 ◽  
Author(s):  
Kaili Wang ◽  
Xiujuan Sun ◽  
Wen Huang ◽  
Qiuhan Cao ◽  
Yongjie Zhao ◽  
...  
Keyword(s):  
Exchange Reaction ◽  
Hydrogen Evolution ◽  
Anion Exchange ◽  
Hydrogen Evolution Reaction ◽  
Acidic Solution ◽  
Carbon Cloth ◽  
Reaction Method ◽  
Anion Exchange Reaction

Nickel cyclotetraphosphate grown on carbon cloth (Ni2P4O12/CC) is synthesized by an anion exchange reaction method and affords excellent hydrogen evolution reaction (HER) activity as well as strong working stability in...

scholarly journals Insights into Hydrogen Evolution Reaction on 2D Transition Metal Dichalcogenides

2021 ◽  
Author(s):  
Zhenbin Wang ◽  
Michael Tang ◽  
Ang Cao ◽  
Karen Chan ◽  
Jens Kehlet Nørskov
Keyword(s):  
Transition Metal ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Adsorption Energy ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Activation Barrier ◽  
Transition Metal Dichalcogenides ◽  
Adsorbed Hydrogen ◽  
Metal Dichalcogenides

<p>Understanding the hydrogen evolution reaction (HER) behaviors over 2D transition metal dichalcogenides (2D-TMDs) is critical for the development of non-precious HER electrocatalysts with better activity. In this work, by combining density functional theory calculations with microkinetic modelling, we thoroughly investigated the HER mechanism on 2D-TMDs. We find there is an important dependence of simulated cell size on the calculated hydrogen adsorption energy and the activation barrier for MoS<sub>2</sub>. Distinct from previous “H migration” mechanisms proposed for the Heyrovsky reaction − the rate-determining step for MoS<sub>2</sub>, we propose the Mo site only serves as the stabilized transition state rather than H adsorption. In comparison to transition metal electrocatalysts, we find that the activation barrier of the Heyrovsky reaction on 2D-TMDs scales with the hydrogen adsorption energy exactly as for transition metals except that all activation energies are displaced upwards by <i>ca.</i> 0.4 eV. This higher Heyrovsky activation barrier is responsible for the substantially lower activity of 2D-TMDs. We further show that this higher activation barrier stems from the more positively charged adsorbed hydrogen on the chalcogenides interacting repulsively with the incoming proton. Based on these insights, we discuss potential strategies for the design of non-precious HER catalysts with activity comparable to Pt.</p>

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