Oxidative carbonylation of methane to acetic acid on an Fe-modified ZSM-5 zeolite

Direct catalytic conversion of methane under mild conditions is beneficial but challenging. Herein, we report a direct co-conversion of methane, carbon monoxide, and hydrogen peroxide into acetic acid, catalyzed by Fe/ZSM-5 (0.25) zeolite under mild conditions. The highest reported acetic acid space-time yield of ∼12.01 mmol gcat−1 h−1 with an optimal selectivity of 63.2% is achieved at 50 °C. This relatively high yield is ascribed to the mononuclear Fe3+ species. 13C-Tracking experiments revealed that the methyl and carbonyl groups of acetic acid originate from methane and carbon monoxide, respectively. Spin-trapping experiments indicated that ∙OH and ∙CH3 radicals are involved in the reaction. In situ Raman analysis suggested that –Fe–OCH3 species is the possible intermediate. Overall, our method is greener, and our catalyst is more economical than those currently used in the industrial process. Therefore, we expect a pilot-scale test to determine the possibility as an industrial alternative. [Display omitted] •Fe/ZSM-5 zeolite catalyzes the direct co-conversion of CH4, CO, and H2O2 into CH3COOH.•The highest acetic acid yield is attributed to the mononuclear Fe3+ species.•The methyl and carbonyl groups of acetic acid stem from CH4 and CO, respectively.•The ∙OH and ∙CH3 radicals are involved in the co-conversion reaction.•An –Fe–OCH3 species is the possible intermediate.