Microenvironment engineering unveils surface methoxy species origination in zeolite-catalyzed methanol chemistry...

Which came first, the chicken or the egg? This age-old riddle is also present for the formation sequence of the surface methoxy species and dimethyl ether in zeolite-catalyzed methanol chemistry due to their inevitable interconversion at high temperatures. The challenge is the lack of feasible reaction conditions to achieve the formation of surface methoxy species by Brønsted acids at mild temperatures. This work proposes a microenvironment design strategy to manipulate the reaction routes inside zeolite channels with the assistance of nitromethane, realizes the surface methoxy species generation catalyzed by Brønsted acids at 363 kelvin, and solves the long-standing problem of the origin and evolution of the highly active surface methoxy species during zeolite Brønsted-acid-catalyzed methanol conversion process. It is found that the surface methoxy species mainly originate from dimethyl ether decomposition under these mild conditions. These findings provide a perspective to subtly manipulate the reaction routes by tailoring the chemical microenvironment, and offer fresh insights into the zeolite-catalyzed methanol chemistry.