Selectively Switching the Hydrocarbon Distribution during Syngas Conversion via Controlling the Hydrogenation Process

Syngas conversion serves as a pivotal process for producing high-value chemicals and fuels from nonpetroleum carbon resources. The oxide–zeolite system has emerged as a promising catalytic platform for syngas conversion, enabling the synthesis of hydrocarbons with specific carbon number ranges. However, the mechanism governing the selective switch of hydrocarbons between olefins and paraffins is still not clear enough, requiring further investigation. In this study, a series of Zn_yCr₁O_x metal oxides are synthesized, and the conversion of syngas into light olefins with 56.7% selectivity or liquefied petroleum gas with 74.1% selectivity is achieved after coupling these metal oxides with SAPO-34 zeolite. Multiple characterizations reveal that the composition of metal oxides significantly influences the formation rate and distribution of hydrocarbons by modulating the adsorption behaviors of the CO and H₂ molecules. Controlling the hydrogenation process during reaction is identified as the critical factor for achieving the selectivity switch between light olefins and liquefied petroleum gas.