Design And Synthesis Of Bioinspired Znzrox&Bio-Zsm-5 Integrated Nanocatalysts To Boost Co2 Hydrogenation To Light Olefins

Transformation of CO2 with the help of green hydrogen prepared from renewable energy) into valuable light olefins (C-2(=)-C-4(=)) is a promising route for utilizing the carbon resource in CO2. Currently, most of the reported bifunctional catalysts for CO2 hydrogenation to light olefins follow a methanol-mediated route that adopts SAPO-34 as the zeolite component. Although ZSM-5 has been widely used in the methanol to propylene process using fixed bed reactors due to high shape-selective property and long lifetime, ZSM-5-based bifunctional catalysts have seldomly been used for CO2 hydrogenation to light olefins. Herein, we proposed a novel synthetic strategy for bio-ZSM-S with mild acid strength and relatively low acid density using the natural rice husk as a template. The bio-ZSM-5 was integrated with ZnZrOx solid solution nanoparticles, and the derived ZnZrOx&bio-ZSM-5 catalysts exhibited a high C-2(=)-C-4(=) selectivity of 64.4% and total C-2-C-4 selectivity of 94.5%, but relatively low CH4 selectivity (5.5%) and aromatic selectivity (<1%). The post-modified ZnZrOx&bio-ZSM-5 catalysts further enhanced the catalytic stability with less coke deposition and regulated the ethylene to propylene ratio in light olefin distribution. Furthermore, *CHxO was found to be the key intermediate formed on the ZnZrOx surface and was transferred to the Bronsted acid sites in the bio-ZSM-5 for the subsequent conversion to light olefins, as confirmed by in situ DRIFTS and chemical trapping mass spectrometry.