Identifying the optimal polymethylbenezens for ethylene production in methanol-to-olefin conversion by simple structural descriptor

Abstract

Methanol-to-olefin (MTO) conversion is a significant non-petrochemical process in the industrial production of light olefins from gas, coal and biomass. Based on the side-chain mechanism, various polymethylbenzenes (polyMB’s) are generated during the MTO process and impact on ethylene formation. Identifying the optimal polyMB’s for different zeolites is necessary for the theoretical evaluation of the performance of zeolites during MTO conversion, but it requires expensive DFT calculations on all possible polyMB’s and is not valid for large-scale screening. Here, we propose the area of cage-defining ring (S_CDR) within zeolite as a simple structural descriptor for the prediction methyl number of optimal polyMB’s species during MTO conversion. Additionally, we identify a new zeolite cage ‘abccbbca_AABBACBACBACBACB’ with high ethylene activity, which is even superior to CHA-type cages, the best zeolite catalysts known so far. Our approach can significantly reduce the computational cost for the prediction of new zeolite catalysts.