Deciphering the reaction network for the acetoxylation of propylene to allyl acetate on PdCu catalysts combined DFT with kMC analysis

Abstract

The acetoxylation of propylene to allyl acetate on PdCu catalysts is a critical step in the Lyondell method for BDO production. By combining Density Functional Theory and kinetic Monte Carlo simulations, the reaction network and the formation pathways of allyl acetate and CO2 were systematically studied. Propylene and acetic acid were both activated by oxygen-assisted dehydrogenation to obtain CH3COO* and CH2CHCH2*, which would participate in the C-O coupling reaction to form allyl acetate, with the apparent activation energy of 0.64 eV. Besides, the dominant paths for the formation of CO2 from the complete oxidation of propylene and acetic acid were identified with the apparent activation energy of 1.80 eV. As the temperature rises, the TOF of allyl acetate and CO2 formation increase gradually, while the molar fraction of allyl acetate in the products decreases, indicating that temperature exerts a greater influence on the formation of CO2 than allyl acetate.