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Photothermal carbon dioxide (CO2) methanation has attracted increasing interest in solar fuel synthesis, which employs the advantages of photocatalytic H2O splitting as a hydrogen source and photothermal catalytic CO2 reduction. This work prepared three-dimensional (3D) honeycomb N-doped carbon (NC) loaded with core–shell NiO@Ni nanoparticles generated in situ at 500 °C (NiO@Ni/NC-500). Under the photothermal catalysis (200 °C, 1.5 W/cm2), the CH4 evolution rate of NiO@Ni/NC-500 reached 5.5 mmol/(g·h), which is much higher than that of the photocatalysis (0.8 mmol/(g·h)) and the thermal catalysis (3.7 mmol/(g·h)). It is found that the generated localized surface plasmon resonance enhances the injection of hot electrons from Ni to NiO, while thermal heating accelerates the thermal motion of radicals, thus generating a strong photo-thermal synergistic effect on the reaction. The CO2 reduction to CH4 follows the *OCH pathway. This work demonstrates the synergistic effect of NiO@Ni and NC can enhance the catalytic performance of photothermal CO2 reduction reaction coupled with water splitting reaction. [ABSTRACT FROM AUTHOR]

Mn-based catalysts have exhibited promising performance in low-temperature selective catalytic reduction of NOx with NH3 (NH3-SCR). However, challenges such as H2O- or SO2-induced poisoning to these catalysts still remain. Herein, we report an efficient strategy to prepare the dual single-atom Ce-Ti/MnO2 catalyst via ball-milling and calcination processes to address these issues. Ce-Ti/MnO2 showed better catalytic performance with a higher NO conversion and enhanced H2O- and SO2-resistance at a low-temperature window (100–150 °C) than the MnO2, single-atom Ce/MnO2, and Ti/MnO2 catalysts. The in situ infrared Fourier transform spectroscopy analysis confirmed there is no competitive adsorption between NOx and H2O over the Ce-Ti/MnO2 catalyst. The calculation results showed that the synergistic interaction of the neighboring Ce-Ti dual atoms as sacrificial sites weakens the ability of the active Mn sites for binding SO2 and H2O but enhances their binding to NH3. The insight obtained in this work deepens the understanding of catalysis for NH3-SCR. The synthesis strategy developed in this work is easily scaled up to commercialization and applicable to preparing other MnO2-based single-atom catalysts. [ABSTRACT FROM AUTHOR]

Homogeneous noble metal catalysts used in alkene hydrosilylation reactions to manufacture organosilicon compounds commercially often suffer from difficulties in catalyst recovering and recycling, undesired disproportionation reactions, and energy-intensive purification of products. Herein, we report a heterogeneous 0.5Ruδ+/ZrO2 catalyst with partially charged single-atom Ru (0.5 wt.% Ru) supported on commercial ZrO2 nanocrystals synthesized by the simple impregnation method followed by H2 reduction. When used in the ethylene hydrosilylation with triethoxysilane to produce the desired ethyltriethoxysilane, 0.5Ruδ+/ZrO2 showed excellent catalytic performance with the maximum Ru atom utilization and good recyclability, even superior to homogeneous catalyst (RuCl3·H2O). Structural characterizations and density functional theory calculations reveal the atomic dispersion of the active Ru species and their unique electronic properties distinct from the homogeneous catalyst. The reaction route over this catalyst is supposed to follow the typical Chalk—Harrod mechanism. This highly efficient and supported single-atom Ru catalyst has the potential to replace the current homogeneous catalyst for a greener hydrosilylation industry. [ABSTRACT FROM AUTHOR]

Four kinds of CuO catalysts with well-controlled leaf-like (L-CuO), flower-like (F-CuO), sea-urchin-like (U-CuO), and oatmeal-like (O-CuO) morphologies were synthesized by a facile precipitation method assisted by various chelating ligands. High-resolution transmission electron microscopy and fast Fourier transform infrared spectroscopy indicated that the dominant crystal facets of L-CuO, F-CuO, U-CuO, and O-CuO were {001}, {1̅10}, {001}, and {110}, as well as {001} and {1̅10}, respectively. When tested for the Rochow reaction, it was found that their catalytic performances were dependent on their structures. Among the four CuO catalysts, L-CuO exhibited the best catalytic property, along with the strongest adsorption ability for oxygen and highest reducibility, which are mainly because of its largely exposed {001} facet and large specific surface area. In addition, the amount of the CuSi alloy phase, which is the most important reaction intermediate that generated in the reacted region of the Si surface, was measured for the different catalysts. Based on the findings, a detailed reaction mechanism was proposed. This work demonstrates that shape-controlled synthesis of oxide catalysts could be an effective strategy to design and develop efficient catalysts. [ABSTRACT FROM AUTHOR]