从理论角度对MoP析氢反应活性的新见解

New Insight on Hydrogen Evolution Reaction Activity of MoP from Theoretical Perspective.

作者信息

Gao Yuyue, Li Hongyan, Wang Jingyu, Ma Jianyi, Ren Haisheng

机构信息

Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.

School of Chemical Engineering, Sichuan University, Chengdu 610065, China.

出版信息

Nanomaterials (Basel). 2019 Sep 5;9(9):1270. doi: 10.3390/nano9091270.

DOI:10.3390/nano9091270

PMID:31492045

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6781081/

Abstract

We systematically investigated the hydrogen evolution reaction (HER) of six facets of MoP2 based on the periodic density functional theory (DFT). The calculated values of Gibbs free energy of hydrogen adsorption (ΔGH) indicated that the (111) facet has a good HER activity for a large range of hydrogen coverages. The zigzagged patterns before 75% hydrogen coverage suggest a facilitation among Mo1, P1 and Mo2 sites, which are attributed to repeat occupancy sites of H atoms. From ab initial atomistic thermodynamics analysis of hydrogen coverage, we gained that the most stable coverage of hydrogen is 18.75% at 1 atm H2 and 298 K. Finally, the doping effects on HER activity were investigated and found that catalytic performance can be improved by substituting P with an S or N atom, as well as substituting the Mo atom with an Fe atom, respectively. We hope this work can provide new insights on further understanding of HER for MoP2 and give instructions for the experimental design and synthesis of transition metal phosphides (TMPs)-based high-performance catalysts.

摘要

基于周期性密度泛函理论（DFT），我们系统地研究了MoP₂六个晶面的析氢反应（HER）。氢吸附吉布斯自由能（ΔGH）的计算值表明，在较大范围的氢覆盖度下，（111）晶面具有良好的HER活性。在75%氢覆盖度之前的锯齿形图案表明Mo1、P1和Mo2位点之间存在促进作用，这归因于H原子的重复占据位点。通过对氢覆盖度的从头算原子热力学分析，我们得出在1 atm H₂和298 K下，氢的最稳定覆盖度为18.75%。最后，研究了掺杂对HER活性的影响，发现分别用S或N原子取代P以及用Fe原子取代Mo原子可以提高催化性能。我们希望这项工作能够为进一步理解MoP₂的HER提供新的见解，并为基于过渡金属磷化物（TMPs）的高性能催化剂的实验设计和合成提供指导。