Enhanced synthesis of light aromatics from CO2 hydrogenation by GaZrOx interfaced with dual-zeolite

Catalytic conversion of CO 2 to light aromatics (including benzene, toluene, and xylene, collectively known as BTX) and olefins is an eco-friendly approach for reducing waste gas emissions, but it remains a significant challenge. Traditional methods that modify the surface acid sites of zeolites to increase BTX selectivity often produce undesired byproducts and involve complex preparation processes. Here, we report a strategy to enhance BTX formation by altering the reaction intermediates using a tandem catalyst composed of metal oxides and dual-zeolite (GaZrO x /SAPO-34/ZSM-5, labelled as GZO/S34/Z5). The inclusion of S34 zeolite facilitates the partial transformation of CO 2 hydrogenation intermediates produced by GZO into light olefins, thereby promoting the aromatic formation in Z5. This results in a 72.6 % selectivity for total aromatics in hydrocarbons, with BTX accounting for a significantly higher selectivity compared to GZO/Z5, representing a 3.4-fold increase from 7.1 % to 24 %. Additionally, by regulating the acid density of Z5, the tandem catalyst with dual-zeolite can directly convert CO 2 and H 2 to 53.5 % aromatics and 25.5 % olefins, with a BTX selectivity of 13.8 % in hydrocarbons. This tandem catalyst design, through adjusting the reaction intermediates, offers an efficient method to inhibit the formation of light paraffin byproducts and enhance BTX selectivity in CO 2 conversion.