scholarly journals Remarkable Enhancement of Catalytic Activity of Cu-Complexes in the Electrochemical Hydrogen Evolution Reaction (HER) by Using Triply-Fused Porphyrin

2022 ◽  
Author(s):  
Biprajit Sarkar ◽  
Shubhadeep Chandra ◽  
Arijit Singha Hazari ◽  
Qian Song ◽  
David Hunger ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
High Efficiency ◽  
Bimetallic Catalyst ◽  
Magnetic Measurements ◽  
Reduction Process ◽  
Porphyrin Complex ◽  
Copper Porphyrin ◽  
Production Of Hydrogen

Developing efficient molecular catalysts for the electrocatalytic hydrogen evolution reaction (HER) is a highly important goal in contemporary science. We report here on a bimetallic triply fused copper porphyrin complex (1) comprising two monomeric porphyrin units linked through β–β, meso–meso, β′–β′ triple covalent linkages, that exhibits remarkable enhancement of catalytic activity for the electrochemical HER in comparison to the analogous monomeric copper porphyrin complex (2). Spectroscopic characterization, in association with magnetic measurements, clearly establish the ground state structures of both the bimetallic and monometallic complexes as containing two and one copper (II) centers, respectively. The fused metalloporphyrin complex is found to undergo electrochemical reduction at a lower negative applied potential compared to the metalloporphyrin monomer, as evident from the significant anodic shift (~800mV) in the potential of the first reduction process. Electrochemical investigations in the presence of a proton source (trifluoroacetic acid) confirm that the catalytic activity of the fused metalloporphyrin occurs at a significantly lower onset potential, (overpotential decreased by ~320 mV), compared to the non-fused monomer. Controlled potential electrolysis combined with the kinetic analysis of catalysts 1 and 2 confirm the production of hydrogen, with 96% and 71% faradaic efficiencies and turnover numbers of 102 and 18, respectively. Kinetic investigations further reveal an observed rate constant of around 107 (s-1), implying high efficiency of the bimetallic catalyst towards hydrogen evolution reaction. Mechanistic insights are presented by using a combination of UV-vis-NIR and EPR spectroscopy and electrochemistry. Our results thus firmly establish the triply fused porphyrin ligands as candidates for generating highly efficient molecular electrocatalysts in combination with transition metal centers.

Tuning the Edge-Site Activity of 2H Phase MoSe2 for Hydrogen Evolution Reaction via Sulfur Substitution and Strain Engineering

2020 ◽  
Vol 12 (10) ◽  
pp. 1446-1456
Author(s):  
Ziwei Xu ◽  
Guanghui Zhao ◽  
Mingyuan Wang ◽  
Jingjing Liang ◽  
Shahid Hussain ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Density Functional ◽  
High Efficiency ◽  
Low Cost ◽  
Catalytic Efficiency ◽  
Strain Engineering ◽  
Catalyst Design ◽  
Potential Candidate

The 2H phase MoSe2 of high chemical stability and excellent catalytic activity is a promising catalyst for the hydrogen evolution reaction (HER) as a potential candidate, due to its low cost, high efficiency and abundant production. However, the HER catalytic efficiency of MoSe2 largely depends on the activity of reaction sites including the basal plane and the edges, and remains low because only the Mo edge sites are active. Herein, we have calculated the structural stability, catalytic activity, and strain engineering on sulfur substituted MoSe2 catalytic structures (Mo(Se1–xSx)2) by density functional theory. The results demonstrate that most of Mo(Se1–xSx)2 monolayers are thermodynamically stable and the HER activity of the Mo(Se1–xSx)2 monolayers can be effectively tuned by both element substitution and strain engineering with the mechanisms uncovered at the atomic level. This study provides the experiments theoretical references for the novel catalyst design of the hydrogen evolution reaction.

Ultrasmall diiron phosphide nanodots anchored on graphene sheets with enhanced electrocatalytic activity for hydrogen production via high-efficiency water splitting

2016 ◽  
Vol 4 (41) ◽  
pp. 16028-16035 ◽  
Author(s):  
Huawei Huang ◽  
Chang Yu ◽  
Juan Yang ◽  
Xiaotong Han ◽  
Changtai Zhao ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Production ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Hydrogen Evolution Reaction ◽  
Active Site ◽  
Electrocatalytic Activity ◽  
High Efficiency ◽  
Graphene Sheets

Active site-enriched Fe2P nanodots anchored on graphene sheets (Fe2P-ND/FG) exhibit enhanced catalytic activity and stability for the hydrogen evolution reaction.

scholarly journals Enhanced hydrogen evolution reaction on hybrids of cobalt phosphide and molybdenum phosphide

2017 ◽  
Vol 4 (3) ◽  
pp. 161016 ◽  
Author(s):  
Si-Ling Fang ◽  
Tsu-Chin Chou ◽  
Satyanarayana Samireddi ◽  
Kuei-Hsien Chen ◽  
Li-Chyong Chen ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Water Electrolysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cobalt Phosphide ◽  
Production Of Hydrogen ◽  
Molybdenum Phosphide ◽  
Diffraction Patterns

Production of hydrogen from water electrolysis has stimulated the search of sustainable electrocatalysts as possible alternatives. Recently, cobalt phosphide (CoP) and molybdenum phosphide (MoP) received great attention owing to their superior catalytic activity and stability towards the hydrogen evolution reaction (HER) which rivals platinum catalysts. In this study, we synthesize and study a series of catalysts based on hybrids of CoP and MoP with different Co/Mo ratio. The HER activity shows a volcano shape and reaches a maximum for Co/Mo = 1. Tafel analysis indicates a change in the dominating step of Volmer–Hyrovský mechanism. Interestingly, X-ray diffraction patterns confirmed a major ternary interstitial hexagonal CoMoP 2 crystal phase is formed which enhances the electrochemical activity.

scholarly journals Facile Synthesis of Well-Dispersed Ni2P on N-Doped Nanomesh Carbon Matrix as a High-Efficiency Electrocatalyst for Alkaline Hydrogen Evolution Reaction

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1022 ◽  
Author(s):  
Fan Yang ◽  
Shuo Huang ◽  
Bing Zhang ◽  
Liqiang Hou ◽  
Yi Ding ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
High Efficiency ◽  
Carbon Matrix ◽  
Catalytic Performance ◽  
Alkaline Media ◽  
Mesh Structure ◽  
Factors Affecting ◽  
The Stability

The development of non-noble metal hydrogen evolution catalysts that can replace Pt is crucial for efficient hydrogen production. Herein, we develop a type of well-dispersed Ni2P on N-doped nanomesh carbon (NC) electrocatalyst by a facile pyrolysis method, which shows excellent hydrogen evolution reaction (HER) catalytic performance. It is rather remarkable that the overpotential of Ni2P/NC prepared under optimal proportion is 108 mV at 10 mA·cm−2 current density in 1 M KOH solution with the tafel slope of 67.3 mV·dec−1, the catalytic activity has no significant attenuation after 1000 cycles of cyclic voltammetry (CV)method. The hydrogen evolution performance of the electrocatalytic is better than most similar catalysts in alkaline media. The unique mesh structure of the carbon component in the catalyst facilitates the exposure of the active site and reduces the impedance, which improves the efficiency of electron transport as well as ensuring the stability of the hydrogen evolution reaction. In addition, we prove that nitrogen doping and pore structure are also important factors affecting catalytic activity by control experiments. Our results show that N-doped nanomesh carbon, as an efficient support, combined with Ni2P nanoparticles is of great significance for the development of efficient hydrogen evolution electrodes.

Recasting Ni-foam into NiF2 nanorod arrays via a hydrothermal process for hydrogen evolution reaction application

2021 ◽  
Author(s):  
Nanasaheb M. Shinde ◽  
Siddheshwar D. Raut ◽  
Balaji G. Ghule ◽  
Krishna Chaitanya Gunturu ◽  
James J. Pak ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Nickel Foam ◽  
Hydrothermal Process ◽  
Reduction Process ◽  
Nanorod Arrays ◽  
Ni Foam

A promising electrode for hydrogen evolution reaction (HER) has been prepared via a reduction process to form NiF2 nanorod arrays directly grown on a 3D nickel foam.

Synergetic Effect of Ni2P and MXene Enhances Catalytic Activity in the Hydrogen Evolution Reaction

2021 ◽  
Vol 60 (3) ◽  
pp. 1604-1611
Author(s):  
Zepeng Lv ◽  
Meng Wang ◽  
Dong Liu ◽  
Kailiang Jian ◽  
Run Zhang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Synergetic Effect

scholarly journals A Mini Review on Doped Nickel-Based Electrocatalysts for Hydrogen Evolution Reaction

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4651
Author(s):  
Yilin Deng ◽  
Wei Lai ◽  
Bin Xu
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Water Electrolysis ◽  
Energy Resources ◽  
Alkaline Media ◽  
Hydrogen Energy ◽  
Heteroatom Doping ◽  
Highly Active ◽  
Production Of Hydrogen

The energy crisis and environmental pollution have attracted much attention and have promoted researches on clean and sustainable hydrogen energy resources. With the help of highly active and stable transition metal nickel-based catalysts, the production of hydrogen from water electrolysis from electrolyzed water has become an inexpensive and efficient strategy for generating hydrogen energy. In recent years, heteroatom doping has been found to be an effective strategy to improve the electrocatalytic hydrogen evolution reaction (HER) performances of nickel-based catalysts in acidic, neutral, and alkaline media. This review will highlight many recent works of inexpensive and readily available heteroatom-doped nickel-based HER catalysts. The evaluation methods for the performances of HER catalyst will be briefly described, and the role of heteroatom doping and its application in nickel-based catalyst will be summarized. This article will also point out some heteroatom doping strategies, which may provide references and inspire the design of other catalysts with dopants.

scholarly journals Catalytic activity of Co-nanocrystal-doped tungsten carbide arising from an internal magnetic field

RSC Advances ◽  
2021 ◽  
Vol 11 (23) ◽  
pp. 14063-14070
Author(s):  
M. Morishita ◽  
A. Nozaki ◽  
H. Yamamoto ◽  
N. Fukumuro ◽  
M. Mori ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Catalytic Activity ◽  
Tungsten Carbide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Pt Nanoparticles ◽  
Internal Magnetic Field ◽  
Co Doped

The catalytic activity of the Co-doped WC is 30% higher than that of Pt nanoparticles for the hydrogen evolution reaction arising from an internal magnetic field.

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