Natural Sunlight IR‐Driven Highly Efficient Synthesis of Acetaldehyde From Bioethanol Over Cu/Fe ₂ O ₃

ABSTRACT

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/Fe ₂ O ₃ , 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 H ₂ 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/Fe ₂ O ₃ interface, where Fe ³⁺ sites promote dissociative ethanol adsorption, and Cu ⁰ sites facilitates C─H bond cleavage.