Fibrous silica mesoporous ZSM-5 for carbon monoxide methanation

•Fibrous silica mesoporous ZSM-5 was prepared by the microemulsion-crystallization.•The presence of oxygen vacancies led to high interparticle porosity and basicity.•Adsorption sites of CO and H2 were promoted by the presence of oxygen vacancies.•Fibrous silica mesoporous ZSM-5 showed excellent catalytic activity in CO methanation.•Fibrous silica mesoporous ZSM-5 was highly accessible with no diffusion limitation.

sA core-shell fibrous silica mesoporous ZSM-5 (FmZSM-5) has been developed by employing microemulsion system coupled with zeolite crystal-seed crystallization method and unprecedented applied in CO methanation. The FmZSM-5 showed greatly enhanced catalytic activity with the rate of CO conversion (0.0708 μmol-CO/m2 s) and the rate of CH4 formation (0.0488 μmol-CH4/m2 s) at 723 K, which is two-fold higher than that of the conventional recrystallized mZSM-5 (RmZSM-5). Besides, it showed high stability with no sign of deactivation up to 50 h. The presence of oxygen vacancies led to the increase in interparticle porosity, basicity, and CO and H2 adsorption sites which are believed to be the keys for remarkably improved in CO methanation. Additionally, the influence of diffusion limitation was indicated to be negligible. Such a unique core-shell fibrous silica mesoporous ZSM-5 and their excellent catalytic properties suggest the significant application possibilities in base-catalyzed reaction especially in the production of methane.

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