Partial oxidation of methane to syngas over transition-metal-free ZSM-5 zeolite

Abstract Transition-metal-free H-ZSM-5 serves as an efficient catalyst for the partial oxidation of methane to syngas with high CO selectivity. By modulating its acidity and aluminum coordination states, this work reveals the essential role of zeolitic acid sites. The active center is identified as extra-framework penta-coordinated aluminum (EFAlV) species generated from framework Al during activation and reaction. Moreover, Brønsted acid sites cooperate synergistically with EFAlV species to enable the selective formation of CO.