Abstract：In this work, the particle size effects of Rh/SiO2 catalysts on the ethylene hydroformylation have been investigated. A series of Rh/SiO2 catalysts with different rhodium metal particle sizes, obtained by adjusting the rhodium loadings with the incipient-wetness impregnation method, were employed in the rhodium-catalyzed ethylene hydroformylation reaction for the synthesis of propionaldehyde. Structure characterization results of the as-obtained Rh/SiO2 catalysts showed that the particle size of the rhodium metal particles over catalyst surface could be effectively regulated by controlling Rh loading, while the Rh loading had negligible effects on the electronic structure of the active phase. The catalytic performance of these catalyst showed that the yield of propionaldehyde exhibited a volcanic curve as a function of rhodium metal particle size upon reaching the equilibrium state of the reaction, where the Rh0.5/SiO2 and Rh0.1/SiO2 catalysts exhibited the highest and lowest propionaldehyde yields of 6.30 mmol/g-Rh mmol and 2.36 mmol/g-Rh, respectively. Further combining the kinetic analysis in terms of the crystal model indicated that the edge site of rhodium metal particles on the Rh/SiO2 catalyst was the main active site for the hydroformylation of ethylene to produce propionaldehyde.
SHI Yao,FANG Yuan,CHEN Wenyao et al. Particle Size Effects of Rh/SiO2 Catalysts on the Ethylene Hydroformylation
[J]. Chemical Reaction Engineering and Technology, 2021, 37(6): 528-533.
