Concentrated‐light‐intensified hydrogenation of Fe‐doped calcium carbonate for CO via photothermal synergistic catalysis

The cement and carbonate‐processing industries remain major sources of process‐related CO 2 emissions. Replacing the conventional thermal decomposition of CaCO 3 with hydrogenation enables the conversion of emitted CO 2 into valuable CO or syngas. To further reduce energy input and accelerate the reaction, for the first time, we propose the use of concentrated sunlight as a renewable energy to intensify CaCO 3 hydrogenation. Under light irradiation, the hydrogenation temperature decreased by 21°C and accelerated by 43.4% at 600°C compared to dark conditions. As a component of cement raw meal, Fe 2 O 3 was selected as photocatalytic dopant. The CaCO 3 composite doped with 5% Fe 2 O 3 achieves easier hydrogenation at only 501°C under light and a 50.5% reduction in reaction time versus pure CaCO 3 in darkness. Based on analyses, a photothermal‐photocatalytic synergistic mechanism is proposed. This solar intensified CaCO 3 hydrogenation offers a new pathway for reducing CO 2 emissions and energy consumption for carbonate industries.