ABSTRACT Water formed during solar‐driven CO hydrogenation induces surface hydroxylation and oxidation of active sites, leading to catalyst deactivation and altered product selectivity. Here, we report a hydrophobic C‐Fe 2 O 3 /Cu catalyst constructed by carbon doping, which tailors the surface chemistry to construct a water‐repellent interface, thereby suppressing H 2 O adsorption and preventing Cu deactivation. Under light irradiation and ambient pressure (0.1 MPa), the optimized 550C‐Fe 2 O 3 /Cu delivers 30.1% CO conversion with 86.0% C 2+ and 50.3% C 5+ hydrocarbon selectivity, while CH 4 is suppressed to below 9%, and stable operation is sustained for 70 h. Operando and ex situ characterizations indicate that the optimized hydrophobic catalyst (water contact angle 115.9°) regulates the local water microenvironment, thereby suppressing CO 2 formation and maintaining a CO 2 selectivity below 4.0%. Concomitantly, CO‐ and H 2 ‐ programmed temperature desorption/reduction reveal enhanced CO uptake and a favorable surface adsorption balance for C─C coupling. In situ optical spectroscopy and density functional theory suggest that the hydrophobic interface strengthens CO adsorption and thermodynamically favors key C─C coupling steps, including *CHO formation and *CH 2 CH 2 evolution. This hydrophobic‐surface strategy enables efficient and durable solar‐driven photothermal CO hydrogenation to long‐chain hydrocarbons under ambient pressure, providing a practical route toward sustainable liquid fuel synthesis.
Yang et al. (Thu,) studied this question.