V2CN2负载过渡金属双原子电催化固氮的第一性原理研究

电催化剂固氮能够在温和条件下催化氮气还原制氨.本工作基于第一性原理计算，系统地探究了分散在二维V₂CN₂上过渡金属二聚体(Fe, Mo, Ru)形成的双原子催化剂用于电催化固氮的可行性.双原子的协同作用使氮气得到较好的活化.吉布斯自由能计算表明，在V₂CN₂负载双铁原子(Fe₂@V₂CN₂)体系进行的催化反应过电位最低，仅为0.25 eV.进一步的分子动力学计算表明Fe₂@V₂CN₂具有较好的结构稳定性，并且该体系能很好的抑制HER反应的发生.通过与Mo₂@V₂CN₂,Ru₂@V₂CN₂体系的比较可知，氮气分子的吸附构型以及HER反应的竞争对催化剂的选择影响很大.我们的计算能够为双原子催化剂的设计提供更多的依据.

First-principles study of V2CN2-supported transition metal dimers for electrocatalytic nitrogen fixation

Electrocatalyst nitrogen fixation can catalyze nitrogen reduction to ammonia under mild conditions. Based on first-principles calculations, this work systematically explores the feasibility of diatomic catalysts formed by transition metal dimers (Fe, Mo, Ru) dispersed on 2D V2CN2 for electrocatalytic nitrogen fixation. The synergistic effect of the diatoms enables the nitrogen to be better activated. The Gibbs free energy calculation shows that the catalytic reaction carried out in the V2CN2 supported double iron atom (Fe2@V2CN2) system has the lowest overpotential, which is only 0.25 eV. Further molecular dynamics calculations showed that Fe2@V2CN2 had better structural stability, and the system could well inhibit the HER reaction. Compared with Mo2@V2CN2 and Ru2@V2CN2 systems, it can be seen that the adsorption configuration of nitrogen molecules and the competition of HER reaction have a great influence on the selection of catalysts. Our calculations can provide more evidence for the design of diatomic catalysts.