Hydroformylation of propene heterogeneously catalyzed by HRh(CO)(PPh3)3 encapsulated in to hexagonal mesoporous silica—Parametric variation and mass transfer study Original Research Article

An in situ encapsulated HRh(CO)(PPh3)3 in to the pores of hexagonal mesoporous silica (HMS) acting as nanophase reactors, was investigated for the catalytic hydroformylation of propene. The encapsulated catalyst (Rh–HMS) was synthesized and characterized by PXRD, FT-IR, surface area measurements and TEM. The catalyst was effectively active with 99% conversion of propene and 100% selectivity to aldehydes. The effects of reaction parameters: temperature, partial pressure of CO and H2, amount of catalyst and HRh(CO)(PPh3)3 to TEOS ratio on conversion, selectivity and rates were investigated in detail. The rates determined in term of the formation of aldehydes were found to be first order with respect to hydrogen pressure. Catalyst showed first order dependence towards its lower amount. CO pressure variation showed positive order towards lower pressure and inhibition at higher pressures. The investigated mass transfer effects on the kinetics indicated that the reaction runs with negligible mass transfer limitations. The heterogenized Rh–HMS catalyst was effectively recycled for six times.