Light oils from methane homologation over hierarchically porous TiO2/SiO2 hybrid catalyst for a non-thermal plasma

초록

Significant effort has been dedicated to the conversion of methane (CH4) into more valuable chemicals, but its direct conversion into longer-chain hydrocarbons remains challenging. Herein, we develop hierarchically porous TiO2/SiO2 (HP-TiO2/SiO2) catalysts with adjustable Ti/Si molar ratios for plasma-assisted CH4 conversion to light oils including gasoline-range and diesel-range hydrocarbons in the C5–C16 range. By exploiting interfacial interactions between block copolymer and homopolymer constituents, precise control over macro- and mesoporous structures is achieved. The hierarchical porosity promotes plasma penetration, CH4 activation and intermediate conversion. The Ti/Si ratio influences chain-growth probability, increasing selectivity for gasoline- and diesel-range hydrocarbons, reminiscent of Fischer-Tropsch synthesis but without high-temperature CH4 reforming. Density functional theory calculation demonstrates the coke-resistant properties of HP-TiO2 catalysts by lowering CH3 desorption energy and increasing the activation barrier for dehydrogenation. This work provides insights into non-thermal plasma-activated catalyst optimizations for CH4 conversion, and offers prospects for direct synthetic fuel and chemical production.

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