二维四角TiC单层片上的析氢反应研究

电解水是目前获得氢气的高效方法之一.过渡金属碳化物因其廉价且在析氢反应(HER)中表现出较高的催化活性而备受关注.我们利用第一性原理首先计算了新型二维四角TiC单层片的稳定性及电子性质,进而计算其表面不同活性位点、不同氢覆盖率下的吸附能、吉布斯自由能(△ GH*)等属性,并且将对应的微观结构进行了系统分析比较,同时结合...

Investigation of the Hydrogen Evolution Reaction on Two-dimensional Tetragonal TiC Monolayer Sheet

The most effective method to obtain sustainable hydrogen energy is the electro-chemical water splitting. More attentions have been attracted by transition metal carbides(TMCs), which couple low cost and high catalytic activity in hydrogen evolution reactions(HER). In this work, via the first principles(DFT), adsorption energy and Gibbs free energy(?G_H) of hydrogen on two-dimensional tetragonal TiC sheet are calculated, which show that the top site of C on the surface is the catalytic active site. We analyzed emphatically the catalytic performance of topC1 and topC2 sites at different hydrogen coverage rates. Interestingly, the catalytic performance of hydrogen at topC1 site decreased with the increase of coverage, on the contrary, that of hydrogen at topC2 site increased with the increase of coverage. Moreover, the Gibbs free energy of hydrogen on the topC2 site at a highest coverage is about -0.0611eV, which indicating that topC2 site can possess good catalytic activity for the HER at the high hydrogen coverage. This work provides a promising two-dimensional catalyst material for the hydrogen evolution reaction of electrochemical reducing water.