Lili Wan

Abstract The surface frustrated Lewis pairs (SFLPs) on defect-laden metal oxides provide catalytic sites to activate H 2 and CO 2 molecules and enable efficient gas-phase CO 2 photocatalysis. Lattice engineering of metal oxides provides a useful strategy to tailor the reactivity of SFLPs. Herein, a one-step solvothermal synthesis is developed that enables isomorphic replacement of Lewis acidic site In 3+ ions in In 2 O 3 by single-site Bi 3+ ions, thereby enhancing the propensity to activate CO 2 molecules. The so-formed Bi x In 2-x O 3 materials prove to be three orders of magnitude more photoactive for the reverse water gas shift reaction than In 2 O 3 itself, while also exhibiting notable photoactivity towards methanol production. The increased solar absorption efficiency and efficient charge-separation and transfer of Bi x In 2-x O 3 also contribute to the improved photocatalytic performance. These traits exemplify the opportunities that exist for atom-scale engineering in heterogeneous CO 2 photocatalysis, another step towards the vision of the solar CO 2 refinery.

Abstract Two-dimensional (2D) materials are of considerable interest for catalyzing the heterogeneous conversion of CO 2 to synthetic fuels. In this regard, 2D siloxene nanosheets, have escaped thorough exploration, despite being composed of earth-abundant elements. Herein we demonstrate the remarkable catalytic activity, selectivity, and stability of a nickel@siloxene nanocomposite; it is found that this promising catalytic performance is highly sensitive to the location of the nickel component, being on either the interior or the exterior of adjacent siloxene nanosheets. Control over the location of nickel is achieved by employing the terminal groups of siloxene and varying the solvent used during its nucleation and growth, which ultimately determines the distinct reaction intermediates and pathways for the catalytic CO 2 methanation. Significantly, a CO 2 methanation rate of 100 mmol g Ni −1 h −1 is achieved with over 90% selectivity when nickel resides specifically between the sheets of siloxene.