A DFT+U Study on Surface Properties and Methane Adsorption Performance of Au₁/ZrO₂ Single-Atom Catalysts

Single-atom catalyst (SAC) is a new type of catalyst with low-cost and high-utilization rate. Its catalytic activity is closely related to the loading mode of single-atom metals. By means of periodic density functional theory (DFT), the surface properties and methane adsorption performance of c-ZrO₂(111) catalyst after adsorption or doping of Au single-atom were investigated. The adsorption energy and doping formation energy of Au single-atom, oxygen vacancy formation energy, adsorption energy of methane, bader charge and density of state was calculated. The results show that Au single-atom adsorbed at the bridge site on c‑ZrO₂(111) surface is the most stable adsorption structure. On the surface of Au₁/ZrO₂-subZr structure, the oxygen vacancy formation energy drops to 0.33 eV. Moreover, methane has the most negative value of the adsorption energy on this surface and has the strongest adsorption capacity. Methane molecules tend to be adsorbed at Au and Zr sites in 3H* configuration, and have obvious interaction and charge transfer with Au₁/ZrO₂-subZr surface, resulting in a large degree of methane activation. These results provide theoretical support for the design of efficient and low-cost single-atom catalysts (SACs) for methane catalysis.