Silanol nest-assisted Rh nanoparticles inducing homogeneous-like kinetics in heterogeneous hydroformylation

Hydroformylation is a pivotal industrial process for high-value chemicals production. So far, compared with homogeneous systems, heterogeneous hydroformylation allows easier separation and recycling to simplify the operation procedure, however, the transformation efficiency toward targeted aldehyde of long-chain olefins remains unsatisfactory. To tackle this, we developed a Rh nanoparticle catalyst supported on BEA-OH zeolite with rich silanol nests, obtained via a simple dealumination treatment. The specific structure locally enriches long-chain olefins near the Rh active centers and enhances the coordination between olefins and metal sites, significantly improving catalytic performance. In 1-octene hydroformylation process, the optimized Rh catalyst reaches a turnover frequency (TOF) of 21,060 h⁻¹ and over 98% yield, exceeding most heterogeneous catalysts and outperforming the classic homogeneous Wilkinson catalyst (TOF ~ 10,000 h⁻¹). In-situ infrared (IR), density functional theory (DFT) calculations, and kinetic studies reveal that the silanol nests promote the enrichment of long-chain olefins near Rh sites (73.85 mg/g) and lower the olefin coordination energy (decreased by 34.4 kJ/mol), thereby inducing a nearly zero-order reaction kinetics with respect to the olefin—an effect previously observed mainly in homogeneous systems. This work offers a strategy to enhance heterogeneous hydroformylation by tuning the surface structure of zeolite-supported Rh nanoparticles.