One-step plasma reforming of CO2[sbnd]CH4 into hydrogen and liquid fuels: The roles of Cu and Fe sites on products distribution

Abstract

Low-carbon plasma-catalysis technology has shown emerging potential for direct conversion of CO2/CH4 into H2 energy and value-added oxygenates at low temperatures. Nevertheless, how to efficiently regulate the distribution of the products and further reveal the catalytic roles of the active sites in plasma-catalysis remains a major challenge. Herein, we exploited 5A zeolite supported catalysts with varied Cu/Fe active sites and further investigated the effects of Ar/H2O additives in this reaction to tune the products distribution. Comprehensive characterization together with the evaluation tests revealed that Cu0 species in Cu/5A was favorable to the formation of CH3OH (18.0%), and Fe2+ in Fe/5A promoted the CH3COOH (7.9%) production. Noted that the addition of Ar greatly enhanced the conversions of CO2 (30.3%) and CH4 (55.6%) and the H2O additive significantly improved the H2 selectivity (56.6%). Upon systemic in-situ DRIFTS and kinetic modelling, the synergistic conversion routes involving the crucial radicals adsorption process over the catalysts surface were proposed. This work provides new insights into the design of highly selective catalysts for tuning the products distribution in the plasma-catalytic co-conversion of CO2/CH4.