Natural Sunlight IR-Driven Highly Efficient Synthesis of Acetaldehyde From Bioethanol Over Cu/Fe₂O₃

Using renewable biomass to synthesize valuable chemicals can reduce fossil fuel dependence and achieve carbon neutrality. Here, for the first time an infrared light-driven catalyst, Cu/Fe₂O₃, was designed to convert bioethanol to valuable acetaldehyde, accompanied by green hydrogen as a by-product, under both indoor IR light and natural sunlight. It achieves an initial acetaldehyde yield of 237 mmol g^-1 h^-1 under indoor IR irradiation and 205 mmol g^-1 h^-1 under real sunlight, with exceptional selectivity (97.7%) and nearly stoichiometric H₂ byproduct production. Notably, the turnover number and initial turnover frequency surpass those of IR-driven systems by at least one order of magnitude and perform competitively with leading energy-intensive UV-vis-driven and thermocatalytic ethanol conversion processes operated up to 573 K. This high performance is attributed to: i) the construction of an efficient IR photons-to-phonons energy conversion channel within the ps timescale to drive localized thermocatalysis; and ii) the synergistic effect on the in situ formed of Cu/Fe₂O₃ interface, where Fe³⁺ sites promote dissociative ethanol adsorption, and Cu⁰ sites facilitates C─H bond cleavage.