Regioselective hydroformylation with subnanometre Rh clusters in MFI zeolite

Abstract

Achieving the regioselective hydroformylation of linear α-olefins to linear aldehydes using solid catalysts with regioselectivities comparable to the corresponding homogeneous process is a great challenge in the chemical industry. Despite the tremendous efforts devoted to this research topic, most of the reported heterogeneous metal catalysts still give considerably lower regioselectivities than well-established homogeneous metal catalysts. Here we show the design of efficient Rh-zeolite catalysts, in which subnanometre Rh clusters are selectively confined in the sinusoidal ten-membered-ring channels of MFI zeolite, for the hydroformylation of long-chain linear α-olefins (C6–C12) into linear aldehydes with very high linear-to-branched aldehyde ratios (up to 400). The exceptional catalytic performances result from the involvement of the MFI zeolite framework as a rigid solid ligand that accommodates subnanometre Rh clusters in the sinusoidal channels of the MFI zeolite. Olefin hydroformylation is traditionally performed with homogeneous catalysts. Here the authors introduce a heterogeneous system based on zeolite-confined Rh clusters that is characterized by high efficiency for the hydroformylation of C6–C12 terminal olefins into linear aldehydes with high selectivity.