Assembling Giant Nanoclusters as Heterogeneous Catalysts for Effectively Converting CO to CO Under Visible Light.

Heterometallic lanthanide-transition metal (3d-4f) nanoclusters with well-defined structures and multiple active sites are excellent vehicles for achieving efficient catalysis and studying heterometallic synergism. In this work, two closely related yet different high-nuclearity nanoclusters, 72-nuclear {NiRE} (1, RE = Pr, Nd, Sm, Eu, and Gd) and 111-nuclear {NiLa} (2), are synthesized using a mixed-ligand strategy. Importantly, the crystal solids of these giant coordination clusters are insoluble when soaking in HO/CHCN and can be used as heterogeneous catalysts for visible-light-driven catalytic conversion of CO to CO. Cluster 2 exhibits a maximum CO production rate of 4800 µmol g h and a CO selectivity of 92% over H. Furthermore, the catalytic properties are investigated of different rare earths in the cluster 1 series, found that 1-Eu exhibited superior catalytic performance under identical conditions, likely due to the lower reduction potential of the europium ions. This study represents the first report of 3d-4f heterometallic nanoclusters as heterogeneous catalysts for photocatalytic reaction and provides a reference for the study of high-nuclearity 3d-4f nanoclusters as catalysts for photocatalytic reduction of CO to CO.