Conversion of CO2 into fuels via solar energy would be a promising strategy to reduce CO2 emissions and produce value-added carbon compounds. However, the development of efficient light-harvesting and photocatalytic systems remains a significant challenge because of scarcity of low-cost and high-efficiency catalysts in CO2 conversion. Herein, a tunable selectivity in photothermal CO2 conversion was demonstrated over a series of Fe-based catalysts developed through a simple hydrogenation/carbonization treatment with commercial Fe3O4 as a precursor. The Fe3O4 catalyst demonstrated a full selectivity toward CO (about 100%) and 11.3 mmol g–1 h–1 activity for the photothermal catalytic conversion of CO2. More importantly, the pure-phase θ-Fe3C produced remarkably high selectivity toward hydrocarbon products (>97%) and superior activity (10.9 mmol g–1 h–1) in the photothermal conversion of CO2. Meanwhile, it is found that the selectivity toward a hydrocarbon (CH x ) can be modulated by the extent of hydrogenation/carbonization of the Fe3O4 precursor. In addition, we demonstrated the vital influence of the nonthermal effect on the enhanced catalytic performance with the Fe-based catalysts during the photothermal conversion of CO2.

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It remains a general challenge to computationally design optimal catalytic structures based on earth-abundant metals for hydrogenation. Here, we demonstrate an effective computational approach based on inverse molecular design to deterministically design optimal catalytic sites on the Cu(100) surface through the doping of Fe and/or Zn, and a stable Zn-doped Cu(100) surface was found with minimal binding energy to H atoms. By the calculations at the level of density functional theory, the optimized catalyst sites are verified to be valid on the Cu(100) surface in an infinite periodic system. We analyze the electronic structure cause of the optimal binding sites using the analysis of the density of states. In addition, we use a Cu29Zn3 atomic cluster, where such an optimum catalytic site is valid on the Cu(100) surface, to understand the role of doped Zn atoms on lowering the H atom binding energy. We found that in the atomic cluster, the atomic orbitals of surface Zn-atoms show less participation in the binding of H atoms, compared to the atomic orbitals of surface Cu atoms. Our study provides valuable chemistry insights on designing catalytic structures using earth-abundant metals, and it may lead to the development of novel Cu-based earth-abundant alloys in bulk, nanoparticles, atomic clusters, or single-atom catalysts for important catalytic applications such as lignin degradation or CO2 conversion.