Solventless autothermic production of energy-intensive furanic biofuels expedited by photothermal effect

Driving C-C coupling reactions to produce biofuels is usually energy-consuming and requires well-tailored catalysts. Herein, a novel photothermal catalytic strategy was developed to be highly efficient for cascade hydroxyalkylation-alkylation (HAA) of various biomass-derived aldehydes/ketones with 2-methylfuran or acetalization of different bioalcohols with furfural to exclusively afford furanic biofuel molecules (up to 94.8 % yield). The developed bio-based SO₃H-functionalized graphene-like catalyst (GLB-SO₃H-700) could complete the HAA and acetalization reactions in 10 min under solvent-free and room-temperature conditions. Infrared thermal imaging revealed that the local photothermal effect of interfacial solar heating could in-situ remove water co-product, thereby improving the reaction selectivity and rate as evidenced by kinetic study. Moreover, the GLB-SO₃H-700 catalyst exhibited good stability and recyclability. The developed SO₃H-functionalized graphene-like photothermal materials hold great potential for catalytic upgrading of biomass into high-quality biofuels under mild conditions.