A DFT Study of the Adhesion of Pd Clusters on ZnO SWNTs and Adsorption of Gas Molecules on Pd/ZnO SWNTs

We investigated the adhesion of Pd nanoclusters on ZnO SWNTs and adsorption of probe gas molecules (O-2, H-2, and CO) on the outside or inside wall of ZnO and Pd-1/ZnO SWNTs by means of density functional theory calculations in this study. Our study shows that the binding of Pd clusters on ZnO is mainly via the Pd-O bond interaction, The Pd monomer has the same adhesion ability on both the outside and the inside wall of ZnO SWNTs. However, we found that the adsorption energy of O-2 is larger on the inside wall of ZnO and Pd-1/ZnO SWNTs than that on the outside one, which is caused by the confinement effect.