团簇Co3NiB2的催化析氢活性

Catalytic Activity of Co3NiB2 for Hydrogen Evolution

为探究Co-Ni-B合金体系的催化析氢性能,基于密度泛函理论在B3LYP泛函条件下,采用Lanl2dz基组对Co3NiB2的初始构型进行优化计算,并选择优化后稳定存在的4种构型作为研究对象.依据前线轨道理论对团簇Co3NiB2催化水析氢时的吸氢反应和解吸反应进行分析,探究出团簇Co3NiB2催化析氢活性的相关结论.研究结果表明:团簇Co3NiB2的4种优化构型均具有较好的催化析氢性能;在吸附氢原子时,团簇各构型的β-HOMO轨道更具优势,且氢原子均吸附在团簇的Co原子上,即Co原子为团簇Co3NiB2的潜在催化活性位点;构型2(2)不仅在吸氢反应中表现出较好的催化效果,其在后续的解吸过程中更是展现出了远好于其他优化构型的催化能力,说明团簇Co3NiB2中催化析氢活性最好的结构模型是构型2(2).

In order to investigate the catalytic hydrogen evolution performance of Co-Ni-B alloy system,based on density functional theory,under the condition of B3 LYP functional theory,the initial configuration of Co3NiB2 is optimized by Lanl2 dz basis set,and four stable configurations after optimization are selected as the research object.According to the frontier orbital theory,the hydrogen absorption and desorption reactions of cluster Co3NiB2 during hydrogen evolution from water are analyzed,and the relevant conclusions about the catalytic activity of cluster Co3NiB2 for hydrogen evolution are obtained.The results show that:The four optimized configurations of cluster Co3NiB2 have good catalytic performance for hydrogen evolution.When adsorbing hydrogen atoms,the β-HOMO orbitals of various configurations of the clusters are more dominant,and the hydrogen atoms are adsorbed on the Co atoms of the clusters,that is,the Co atoms are the potential catalytic active sites of the cluster Co3NiB2.The 2(2)not only shows good catalytic effect in hydrogen absorption reaction,but also shows much better catalytic ability than other optimized configurations in the subsequent desorption process,indicating that configuration 2(2)is the best structural model for catalytic hydrogen evolution in cluster Co3NiB2.