Density functional theory analysis of hydrogen evolution of cluster Mo3S4

Abstract

In order to explore the hydrogen evolution mechanism at the micro level of cluster Mo3S4, the full-parameter optimization and frequency calculation of cluster Mo3S4 in single and triple states were carried out based on the B3LYP level of density functional theory, and eight optimized configurations were obtained. The stability and catalytic hydrogen evolution activity were analyzed based on the frontier orbital theory, and the results showed that configuration 1(1) had the best thermodynamic stability, and configuration 4(1) had the worst thermodynamic stability. In the first step of hydrogen absorption reaction, the energy level difference of configuration 1(1) is the largest compared with other configurations, that is, it is the most difficult for HOMO orbit to give electrons and then bond with hydrogen atoms. On the contrary, the electrons of configuration 4(3) HOMO orbit are most likely to flow into the LUMO orbit of water molecules and bond with hydrogen atoms to form Mo3S4—H. Configuration (4(1))—H showed the highest desorption capacity in the second desorption reaction. In the desorption process, the energy level difference between HOMO orbital of configuration 4(3) and LUMO orbital of water molecule is the smallest, indicating that the reaction activity is the strongest. Configuration 4(3) shows better catalytic effect than other configurations in hydrogen absorption reaction, so configuration 4(3) has the best catalytic activity in cluster Mo3S4.

Keywords

• cluster mo3s4
• density functional theory
• hydrogen evolution reaction
• frontier orbital theory