Application of graphene/two-dimensional amorphous ZrO2 supported Pd single atom catalysts in CO oxidation: First principles

Abstract

• The development and design of transition metal single atomic catalysts with high stability and high reaction activity is an urgent but challenging task at the same time. In this paper, the crystal (amorphous) ZrO2/graphene sandwich structure supported transition noble metal Pd single atom catalysts was designed creatively, and the interlayer oxidation of CO was studied. In the theoretical calculation, we find that the SACs with this structure has a high carrier mobility. At the same time, the formation energy, the adsorption energy of Pd and the surface energy of IS and FS fully confirm that the sandwich structure can exist stably, and the single atom has effective chemical adsorption on this structure. Graphene rotation will also better protect the surface of ZrO 2 adsorbed by Pd single atom. It further affects the environment of electron distribution, activates the dissociation of CO molecules, and speeds up the progress of the reaction. Therefore, the sandwich structure combines the advantages of the two materials and plays an important role in the stability, adsorption configuration, electron transfer mechanism, adsorption energy and potential barrier of single atom catalysts. Based on the first-principles method of density functional theory (DFT), a two-dimensional graphene/amorphous ZrO 2 composite carrier supported precious metal Pd single atom catalyst was designed, and the catalytic efficiency and catalytic stability of CO to CO 2 in limited domain were discussed. And the effect of the rotation angle between graphene and catalyst carrier on its performance was studied. The electronic properties, transition energy barrier and partial density of states of the relaxed catalysts were calculated and analyzed by first-principles method. The results show that the sandwich structure has good stability and high electron migration, while the corner structure protects the precious metal from escaping from the surface. The reaction energy barrier shows that the catalyst can complete the reaction within the energy barrier of 0.1~0.6 eV in the process of CO catalysis, and the rotation angle can move the reactant orbit faster near the Fermi level, speeding up the reaction. We propose a structural design method for a new type of single atom catalyst, and provide a reliable design basis and new design ideas for CO catalytic oxidation and green energy.