As one of the most important carbon-based building blocks in chemical industry, aromatics produced from traditional petroleum route cannot meet the market demand. In recent years, selective hydrogenation of CO2 to aromatics has attracted much attention, due to its cutdown of CO2 emission and substitution for scarce fossil fuel. In this work, a composite catalyst, composed of Cu promoted Fe2O3 and HZSM-5, was designed for selective CO2 conversion to aromatics, over which high aromatics selectivity of 56.61% and low CO selectivity of 3.51%, with remarkable CO2 conversion of 57.30% were achieved in a single pass. Additionally, the intrinsic effects of Cu doping and CO reduction on catalytic behavior were also in depth investigated through multiple characterizations. It was found that Cu doping is beneficial to the activation and transformation of H2 and CO, as well as improvement of electronic property of iron phase. Simultaneously, CO reduction prior to reaction can facilitate the formation of surface oxygen vacancy and iron carbide, which play crucial roles in CO2 adsorption and FTS, respectively. With respect to the desirable BTX selectivity, Cu-Fe2O3 was integrated with self-fabricated HZSM-5 by phased-transfer method, achieving 54.18% BTX selectivity in aromatics without debasing the catalytic activity, due to the abundant intercrystalline mesopores within zeolite. With a series of experimental design, it was found that H species derived from dehydrogenative aromatization on HZSM-5 can diffuse to Cu-Fe2O3, and then reacted with adsorbed CO2 on the surface via reverse water-gas shift (RWGS) and Fischer-Tropsch synthesis (FTS), generating light olefins to supplement its consumption, which is named “H recycling” mechanism.

High conversion to aromatics via CO2-FT over Cu-Fe2O3/HZSM-5 composite catalyst

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.