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Improving the selectivity and retaining the efficiency of catalysts are essential for industrial processes and remain a great challenge. Herein, we developed a facile route to synthesize Pd nanocubes (NCs) using Eosin Y as the photosensitizer under visible light. Subsequently, Pd NCs were uniformly loaded on N-doped carbon nanofibrous microspheres (NCMs) from carbonated chitin microspheres. This Pd NCs@NCM exhibited high reactivity and selectivity in alkyne semihydrogenation. For example, the hydrogenations of phenylacetylene to styrene and of 3-phenyl-2-propyn-1-ol to (Z)-cinnamyl alcohol were 12.9 and 18.3 times faster with Pd NCs@NCM than with Lindlar catalyst. According to the Mott–Schottky effect, loading of Pd NCs on N-doped carbon constructed a rectifying contact and decreased the electron density of Pd NCs. Density functional theory (DFT) calculations suggested that the high concentration of holes doped in Pd NCs weakened the interaction of alkenes on the Pd (100) facet and prevented further hydrogenation for a long time; this period of durable time is very helpful in chemical manufacturing. Thus, Pd NCs@NCM maintained both high reactivity and selectivity in comparison with surface-modified catalysts. This work provides an alternative strategy to design Mott–Schottky catalysts for selective hydrogenation reactions.

Pt−Fe intermetallic compound (IMC) catalysts, including Pt3Fe, PtFe and PtFe3, are shown to have advantageous catalytic properties similar to those reported for single‐atom alloy catalysts. Suppresion of the Pt ensembles responsible for hydrogenolysis results in high olefin selectivity during propane dehydrogenation. In situ resonant inelastic X‐ray scattering (RIXS) results and density functional theory calculations show that these changes are associated with a decrease in the average energy of the filled 5d states of Pt in the Pt−Fe intermetallic compound structures compared to monometallic Pt, accompanied by an increase in the average energy of the unfilled valence bands. The decrease in energy of the filled Pt 5d orbitals increases with increasing Fe content in the IMC, i.e. PtFe3>PtFe>Pt3Fe. These results demonstrate that by altering the stoichiometry of IMC catalysts it is possible to control both the ensemble size and electronic properties of active sites, which affords another mechanism for tuning catalytic properties, in addition to changing promoter metals. The present study demonstrates the potential of ordered intermetallic compounds as an alternative to traditional solid‐solution single‐atom alloys to serve as catalysts with well‐defined and uniform active sites.

Well-defined organoplatinum(IV) sites were grafted on a Zn(II)-modified SiO support via surface organometallic chemistry in toluene at room temperature. Solid-state spectroscopies including XAS, DRIFTS, DRUV-vis, and solid-state (SS) NMR enhanced by dynamic nuclear polarization (DNP), as well as TPR-H and TEM techniques revealed highly dispersed (methylcyclopentadienyl)methylplatinum(IV) sites on the surface ((MeCp)PtMe/Zn/SiO, 1). In addition, computational modeling suggests that the surface reaction of (MeCp)PtMe with Zn(II)-modified SiO support is thermodynamically favorable (Δ G = -12.4 kcal/mol), likely due to the increased acidity of the hydroxyl group, as indicated by NH-TPD and DNP-enhanced O{H} SSNMR. In situ DRIFTS and XAS hydrogenation experiments reveal the probable formation of a surface Pt(IV)-H upon hydrogenolysis of Pt-Me groups. The heterogenized organoplatinum(IV)-hydride sites catalyze the selective partial hydrogenation of 1,3-butadiene to butenes (up to 95%) and the reduction of nitrobenzene derivatives to anilines (up to 99%) with excellent tolerance of reduction-sensitive functional groups (olefin, carbonyl, nitrile, halogens) under mild reaction conditions.