Role of metal co‐cations in improving CuY zeolite performance for DMC synthesis: A theoretical study

Abstract

First principle calculations based on density functional theory are conducted to investigate the influence of metal cations including Mg2+, Ca2+, Sr2+, Ba2+, La (OH)2+ and Ce (OH)2+ in the small cage of zeolite on the electronic environment of adjacent active center, Cu+ in CuY zeolite as well as the process of CO insertion into CH3O to form CH3OCO for oxidative carbonylation of methanol. The study explains the theoretical reasons for the effects of metal cations on the catalytic activity of zeolites. It was found that, the presence of co‐cations in the small cage can affect the electronic properties and also the catalytic activity in two ways. Firstly, the presence of co‐cations, viz., Ca2+, Sr2+, Mg2+, Ba2+ and La species in small cage hinders the migration of active Cu+ cations from the super cage to small cage. Secondly, the co‐cations greatly affect the charge transfer from zeolite framework to Cu+ present in the adjacent super cage, leading to the increase of the net charge and binding energy of Cu+. The findings can improve the CO adsorption and insertion efficiencies, and the stability of transition states, which results in the enhanced catalytic activity of corresponding zeolites.