A Novel Method of 3D Printing High-Loaded Oxide/H-ZSM-5 Catalyst Monoliths for Carbon Dioxide Reduction in Tandem with Propane Dehydrogenation

Oxidative propane dehydrogenation using CO2 (CO2-ODHP) is a potential alternative for propylene synthesis. In this study, bifunctional catalysts (V2O5, ZrO2, Cr2O3, and Ga2O3 doped H-ZSM-5) are synthesized through additive manufacturing for CO2-ODHP. Characterization and correlation between the various characterizations and the catalytic results indicates that the direct 3D printing of metal oxides alongside H-ZSM-5 can considerably modify the surface properties and bulk oxide phase dispersion, thus leading to enhanced metal oxide reducibility and exceptional CO2-ODHP performance. Among the metal monoliths, the mixed oxide sample with 5 wt% Cr, 10 wt% V, 10 wt% Zr, 10 wt% Ga and 65 wt% H-ZSM-5 displays the best activity, achieving approximate to 40% propane conversion, 95% propylene selectivity, and zero benzene/toluene/xylene production. Upon eliminating CO2, the catalyst monoliths all retain their long-term stability; however, the propane conversions decrease by approximate to 3% and the propylene selectivities decreased by 5-15%. Nevertheless, all five samples examined here demonstrate exceptional catalytic activities and prolonged stabilities, which are attributed to the even distribution of surface acid sites produced by direct printing of the oxide and zeolite components. Overall, this study presents a novel way of manufacturing bifunctional structured catalysts that exhibit exceptional ODHP performance.