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Different from isolated metal atoms and large metal nanoparticles (NPs), supported metal clusters (SMCs) possess distinct geometric and electronic structures and thus exhibit enhanced activity and designated selectivity in catalysis. So far, with the development in synthetic methodologies and characterization techniques, SMCs with fine structures could be constructed and well-defined at the atomic level. In addition, based on computational modeling of SMCs, theoretical calculations corroborated well with experimental results, providing in-depth insights into the structure–property relationship for SMCs in catalysis. In this Review, classic synthetic strategies and key characterization techniques of SMCs are summarized. Subsequently, the applications of SMCs in important catalytic reactions based on recent studies are discussed, including aerobic oxidation, hydrogenation, dehydrogenation, water–gas shift (WGS) reaction, and photocatalytic reactions. In particular, the importance of the cluster size-effect and metal–support interactions in determining the catalytic performance of SMCs is highlighted. Lastly, challenges and prospects in SMCs’ catalysis are illustrated.

Enhancing the intrinsic activity and space time yield of Cu based heterogeneous methanol synthesis catalysts through CO2 hydrogenation is one of the major topics in CO2 conversion into value-added liquid fuels and chemicals. Here we report inverse ZrO2/Cu catalysts with a tunable Zr/Cu ratio have been prepared via an oxalate co-precipitation method, showing excellent performance for CO2 hydrogenation to methanol. Under optimal condition, the catalyst composed by 10% of ZrO2 supported over 90% of Cu exhibits the highest mass-specific methanol formation rate of 524 gMeOHkgcat−1h−1 at 220 °C, 3.3 times higher than the activity of traditional Cu/ZrO2 catalysts (159 gMeOHkgcat−1h−1). In situ XRD-PDF, XAFS and AP-XPS structural studies reveal that the inverse ZrO2/Cu catalysts are composed of islands of partially reduced 1–2 nm amorphous ZrO2 supported over metallic Cu particles. The ZrO2 islands are highly active for the CO2 activation. Meanwhile, an intermediate of formate adsorbed on the Cu at 1350 cm−1 is discovered by the in situ DRIFTS. This formate intermediate exhibits fast hydrogenation conversion to methoxy. The activation of CO2 and hydrogenation of all the surface oxygenate intermediates are significantly accelerated over the inverse ZrO2/Cu configuration, accounting for the excellent methanol formation activity observed.

Carbon-carbon bond-forming reductive elimination from elusive organocopper(III) complexes has been considered the key step in many copper-catalyzed and organocuprate reactions. However, organocopper(III) complexes with well-defined structures that can undergo reductive elimination are extremely rare, especially for the formation of Csp 3-Csp 3 bonds. We report herein a general method for the synthesis of a series [alkyl-Cu III-(CF 3) 3 ]complexes, the structures of which have been unequivocally characterized by NMR, mass spectrometry and X-ray crystal diffraction. At elevated temperature, these complexes undergo reductive elimination following first-order kinetics, forming alky-CF 3 products with good yields (up to 91%). Both Kinetic studies and DFT calculations indicate that the reductive elimination to form Csp 3-CF 3 bonds proceeds through a concerted transition state, with a ΔH ‡ =20 kcal/mol barrier.

Solar-driven Fischer-Tropsch synthesis represents an alternative and potentially low-cost route for the direct production of light olefins from syngas (CO and H ). Herein, a series of novel Co-based photothermal catalysts with different chemical compositions are successfully fabricated by H reduction of ZnCoAl-layered double-hydroxide nanosheets at 300-700 °C. Under UV-vis irradiation, the photothermal catalyst prepared at 450 °C demonstrates remarkable CO hydrogenation performance, affording an olefin (C ) selectivity of 36.0% and an olefin/paraffin ratio of 6.1 at a CO conversion of 15.4%. Characterization studies using X-ray absorption fine structure and high-resolution transmission electron microscopy reveal that the active catalyst comprises Co and Co O nanoparticles on a ZnO-Al O mixed metal oxide support. Density functional theory calculations further demonstrate that the oxide-decorated metallic Co nanoparticle heterostructure weakens the further hydrogenation ability of the corresponding Co, leading to the high selectivity to light olefins. This study demonstrates a novel solar-driven catalyst platform for the production of light olefins via CO hydrogenation.