Substrate influences on activity and stability of SBA-15-Pr-anchored Rh-P complex catalysts for olefin hydroformylation

RhCl3 was immobilized to diphenylphosphinopropyl (-PrPPh2)-modified mesoporous silica SBA-15 through a multi-step-assembly process. The prepared catalyst was characterized with reference to bulky and surface properties by X-ray diffraction (XRD), infrared spectroscopy (FT-IR), isothermal nitrogen sorption analysis and X-ray photoelectron spectroscopy (XPS). The metal content was determined by inductive coupling plasma-atomic emission spectroscopy (ICP-AES). The prepared rhodium-immobilized catalyst was employed in hydroformylation of several higher olefins of different lengths (C-6, C-8, and C-10), different C=C bond positions (terminal or internal) or different structures (linear or branched). The substrate influences on the activity and recycling stability of the immobilized catalyst were investigated and are discussed. Shorter linear olefin substrates were more easily activated with higher catalyst specific activity, while the catalyst showed recycling stability in hydroformylation of longer and branched olefin substrates. For comparison, PPh3 was externally added to immobilize RhCl3 to -PrPPh2-modified SBA-15. The immobilized catalyst so prepared showed a more flexible immobilizing structure and revealed a promoted turnover number of substrates. (C ) 2010 Elsevier B.V. All rights reserved.