Lowering the Kinetic Barrier via the Synergistic Catalysis\nof N‑CNTs Supported RhP Subnanoclusters and Confined Co Nanoparticles\nfor Olefins Hydroformylation

Developing\nsynergistic sites for a multistep elementary reaction\nis important, but challenging. Herein, the coexistence of Co nanoparticles\nconfined inside the carbon nanotubes and RhP subnanoclusters loaded\non the outside of carbon nanotube (Co@N-CNTs|RhP) is synthesized by\na defect-assisted impregnation strategy. Notably, Co nanoparticles\nand RhP subnanoclusters have a synergistic engineering distance of\n0.66 nm. The turnover frequency over Co@N-CNTs|RhP catalyst could\nreach 82603 h<sup>–1</sup> during the diisobutylene hydroformylation,\n15 times higher than that of the commercial Rh homogeneous catalysts.\nMore importantly, the obtained Co@N-CNTs|RhP achieved 25 catalytic\ncycles. Kinetic experiments show that the synergistic engineering\nof confined Co nanoparticles and RhP subnanoclusters is the key to\npromote the hydroformylation of diisobutylene, which reduces the activation\nenergy to 64.6 kJ/mol. Further in situ DRIFT spectra and theoretical\ncalculations reveal the confined Co nanoparticles modified by RhP\nsubnanoclusters are conducive to the adsorption of H<sub>2</sub>,\nCO, and diisobutylene, while the RhP subnanoclusters are responsible\nfor the formation of aldehydes. This work provides profound insight\nfor the construction of efficient multisite heterogeneous catalyst\nfor long-chain olefin conversion reactions.