Rational Design of PdAg Catalysts for Acetylene Selective Hydrogenation via Structural Descriptor-based Screening Strategy

Pd-based catalysts are widely used in selective hydrogenation reactions, where the surface structure has been found as a key factor to improve the yield of the target product. However, little study is involved in a prediction model for rationally engineering the surface structure of Pd-based catalysts with their catalytic properties. Here, using PdAg bimetal catalyzed acetylene selective hydrogenation as a probe reaction, we combined density functional theory calculations and microkinetic models and then revealed structure–performance relationships for PdAg bimetal based on structure descriptors, which qualitatively reflect the ligand effect and stress effect on the adsorption of reactants. The descriptor-based screening strategy allows us to rationally engineer the surface status (element composition and atomic arrangement) of PdAg bimetals and identify candidates with an optimized yield of ethylene product, namely, Pd1Ag3 alloy, which is further confirmed by available references and our catalysis experiments. This screening strategy based on structure descriptors may be generalized for rationally designing the surface structure of Pd-based catalysts for other hydrogenation reactions beyond acetylene selective hydrogenation.