Fully Exposed Platinum-Palladium Heteronuclear Cluster for Enhanced Multi-Step Hydrogenation of Dinitroaromatics.

Fully exposed cluster catalysts (FECCs) exhibit significant potential for hydrogenation reactions due to their maximized atom utilization efficiency and multi-active sites. However, further enhancing their catalytic performance in complex multi-step hydrogenations remains challenging. Herein, we report a fully exposed Pt-Pd heteronuclear cluster (PtPd/ND@G), featuring adjacent Pd single atom (Pd) modified fully exposed Pt clusters (with an average number of atoms of 4). Structural characterization and theoretical calculations reveal that the adjacent Pd serves as an additional adsorption site for the nitro group in dinitrotoluene, inducing the dinitrotoluene molecule to adopt a bidentate configuration between the Pt clusters and the Pd site and achieving the optimal adsorption strength. Concurrently, charge transfer from Pd to Pt clusters elevates the charge density of the Pt clusters, facilitating H dissociation. As a result, the PtPd/ND@G catalyst exhibits superior activity and stability in the multi-step hydrogenation of DNT, achieving a remarkable turnover frequency (TOF) of 64,109 h, substantially surpassing the performance of state-of-the-art catalysts reported in the literature. This work provides a strategic guideline for designing FECCs and offers valuable insights into atomic-level manipulation of catalytic sites for multi-step hydrogenation reactions.