Tuning the regioselectivity of heterogeneous hydroformylation by engineering carbon species microenvironment around Rh sites

Abstract

Olefin hydroformylation is one of the most important industrial processes for aldehyde synthesis. Heterogeneous catalysts are easy to separate compared with homogeneous catalysts, yet with limited success in activity and regioselectivity control. In the present work, a zeolite-encapsulated rhodium carbide species (RhC_x@S-1) catalyst was developed, demonstrating not only relatively high catalytic activity but also good regioselectivity and stability in heterogeneous propylene hydroformylation. The unique microenvironment of rhodium carbide species was formed in situ during the catalyst carbonization reduction process, tuning the steric and electronic characteristics of Rh species to obtain more linear aldehydes. This work shows an alternative strategy to promote the regioselectivity of olefin hydroformylation catalyzed by zeolite-confined catalysts and provides insights into the selective regulation of heterogeneous catalysts.