LAUSR

Photocatalytic C‒C coupling of 2,5-dimethylfuran (DMF) derived from processing lignocellulosic biomasses co-produces drop-in fuels and green hydrogen with a low-carbon footprint. However, the high reaction barrier for C‒H bond breaking and uphill overall reaction lead to the slow kinetics of DMF coupling. Here, we reveal that [HSO4-] and water can collaboratively promote the rate-limiting step of the C‒H bond breaking on the Ru-ZnIn2S4 catalyst. An in-depth study suggests that water mediates hole transfer to the C‒H bond while [HSO4-] facilitates electron extraction, thus promoting electron and proton transfer on the Ru-ZnIn2S4 surface. Consequently, photocatalytic DMF coupling over Ru-ZnIn2S4 produces diesel fuel precursors (DFPs) and H2 with benchmarking formation rates of 1.5 g gcatal.-1 h-1 and 9.7 mmol gcatal.-1 h-1, respectively. Moreover, the selectivity of branched-chain DFPs reaches 55%. This work puts forward new insight and strategy for photocatalytic C‒C coupling for the synthesis of biofuels.