Quantum Catalytic Performance for the Hydrogen Evolution Reaction and the Ethanol Oxidation Reaction in Topological Edge States of SrPd and BaPd Semimetal Monolayers: A Theoretical Study

Catalysis plays an important role in human society. Quantum catalysis theory using topological materials is a new catalyst design theory developed in recent years. In this article, a new type of two-dimensional topological nodal line semimetals material (2D TNLSM), consisting of a SrPd or BaPd monolayer, is designed by density functional theory (DFT) calculations. Due to the presence of both time-reversal and spatial-inversion symmetries, the band crossings persist along a closed path around the Y point in the 2D Brillouin zone, which leads to topological edge states with a high electronic density of states near the Fermi level. The partially unoccupied topological edge states originating from the Pd d orbitals behave as electron acceptors and share part of electrons provided by the trivial edge states. Therefore, the interaction between the Pd active sites at SrPd and BaPd edges and H is weakened, contributing to an optimized binding strength toward H adsorption. Thus, the Heyrovsky reaction becomes a rate-determining step (RDS), leading to an excellent hydrogen evolution reaction (HER) catalytic efficiency. In addition, this kind of Pd-containing catalyst also has good catalytic performance for the ethanol oxidation reaction (EOR). These results deepen the understanding of the HER and EOR mechanisms for twodimensional topological materials and provide a new idea for HER and EOR catalyst design.