Atomically precise nanoclusters (APNCs), as ideal model catalysts, revealed great advantages to deep-understand of reaction mechanisms in heterogeneous catalysis. Boosting the activity of APNCs is the most critical issue under the premise of maintaining structure invariance. Herein, utilizing Metal-Support Interaction (MSI) strategy, we prepared an excellent and recyclable catalyst for aerobic oxidation by combination of an otherwise inert nanocluster [Pd 3 Cl(PPh 2 ) 2 (PPh 3 ) 3 ] + [SbF 6 ] À (denoted as Pd 3 Cl) with functional titanate nanotubes (TNT). The promising Pd 3 Cl/TNT composite gives rise to excellent conversion with 100% selectivity without any additives at 30 8C under an oxygen pressure. This result is unprecedented in ligand-on nanocluster catalysts without high temperature calcination. The distinct difference between their activities of Pd 3 Cl/TNT composite and fresh Pd 3 Cl nanocluster is explained by the presence of the MSI effect, as confirmed using X-ray photoelectron spectroscopy (XPS) analysis. Theoretical simulations are further carried out to elucidate the catalytic mechanism, indicating the MSI effect promotes the crucial b-H elimination step in both kinetic and thermodynamic aspects. This work presents the example of atomic-level understanding of the effect of MSI on facilitating the APNCs catalytic properties.

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Heterobimetallic dinuclear lanthanide alkoxide complexes Ln2Na8(OCH2CH2NMe2)12(OH)2 [Ln: I (Nd), II (Sm), III (Yb) and IV (Y)] were used as efficient acid–base bifunctional catalysts for the synthesis of carbamates and the N-Boc protection of amines.

Metal clusters with different sizes and shapes may have very different optical, electronic, magnetic, and catalytic properties. The possible geometrical structures of Pd m (m = 3–12, the number of Pd atoms) have been explored by the combination of a modified Morse potential driven genetic algorithm search with density functional theory (DFT) calculations. By using the clustering analysis of DFT data, the studied Pd m clusters were grouped into two families of m > 8 (with longer average interatomic distance and larger atomization energy) and m < 8, respectively. The Pd8 cluster just stands in between these two groups. The relative stability, adsorption energy of CO and O2, and CO oxidation activity of planar (2D) and nonplanar (3D) Pd8 clusters with and without TiO2(110) substrate have been studied theoretically and experimentally, in comparison with the catalytic behavior of low-dimentional Pd1 and Pd3 clusters. The adsorption of CO does not largely affect structures of supported and unsupported 3D Pd8 clusters. But the simultaneous adsorption of CO and O2 could alter the CO oxidation activity of supported Pd8 clusters. The barriers of the rate-determining steps of CO oxidation on the supported low-dimensional Pd1, Pd3, and 2D Pd8 clusters were lower than that of the supported 3D Pd8 clusters. This was supported experimentally by the lower activation energy of CO oxidation on the supported Pd3 cluster (Pd3/TiO2) than that on the supported 3D Pd nanoparticles (Pd NPs/TiO2). The X-ray photoelectron spectroscopy of the Pd3/TiO2 and Pd NPs/TiO2 indicates that the interfacial charge transfers from the Pd cluster to the TiO2 substrates, which is in agreement with the calculation results.