Lu Linguo, Yu Shansheng
Key Laboratory of Automobile Materials of MOE and Department of Materials Science, Jilin University, Changchun 130012, China.
Key Laboratory of Automobile Materials of MOE and Department of Materials Science, Jilin University, Changchun 130012, China.
J Colloid Interface Sci. 2021 Jul;593:116-124. doi: 10.1016/j.jcis.2021.02.132. Epub 2021 Mar 9.
Pentlandite is reported to exhibit good catalytic activity in hydrogen evolution reaction (HER). Many studies have paid attention to metal catalysis of pentlandite. However, the nonmetal catalysis is not considered for HER. Here, we unravel one probable catalytic mechanism of pentlandite toward HER using density functional theory. In our study models, (001) and (100) surfaces are created because there are three types of S-bridged M-M groups on them. Our study reveals that (Fe-Ni)-S center has a moderate value of Gibbs free energy while the corresponding value for (Fe-Fe)-S or (Ni-Ni)-S center is largely positive or negative. In (Fe-Ni)-S group, Fe and Ni can regulate the antibonding state of S, and then balance adsorption and desorption of proton. In addition, an intrinsic electronic potential difference exists between Fe and Ni in (Fe-Ni)-S group, which may boost the charge transfer. Particularly, (Fe-Ni)-S groups are perpendicular to the surface, and four of them make up one closed loop in the surface. It is suggested that the behaviors of such configuration composed of reaction centers resemble edge sites along the layers of MoS toward HER. This study provides a deep insight into the synergistic effect of S-bridged Fe-Ni groups and enables the modulation of electrocatalytic reaction of pentlandite toward HER.
据报道，镍黄铁矿在析氢反应（HER）中表现出良好的催化活性。许多研究都关注了镍黄铁矿的金属催化作用。然而，对于析氢反应，尚未考虑其非金属催化作用。在此，我们使用密度泛函理论揭示了镍黄铁矿对析氢反应的一种可能的催化机制。在我们的研究模型中，创建了(001)和(100)表面，因为它们上面存在三种类型的S桥连M-M基团。我们的研究表明，(Fe-Ni)-S中心的吉布斯自由能具有适中的值，而(Fe-Fe)-S或(Ni-Ni)-S中心的相应值则大多为正或为负。在(Fe-Ni)-S基团中，Fe和Ni可以调节S的反键态，进而平衡质子的吸附和解吸。此外，(Fe-Ni)-S基团中的Fe和Ni之间存在固有的电子电位差，这可能会促进电荷转移。特别地，(Fe-Ni)-S基团垂直于表面，并且其中四个在表面构成一个闭环。有人认为，由反应中心组成的这种构型的行为类似于MoS层状结构对析氢反应的边缘位点。这项研究深入洞察了S桥连Fe-Ni基团的协同效应，并实现了对镍黄铁矿析氢电催化反应的调控。
