Controlling hydrogenation of C=O and C=C bonds in cinnamaldehyde using silica supported Co-Pt and Cu-Pt bimetallic catalysts

Liquid phase hydrogenation of cinnamaldehyde was evaluated over SiO2 supported Co-Pt and Cu-Pt bimetallic and Co, Cu, Pt monometallic catalysts in a batch reactor. H-2-temperature-programmed reduction (H-2-TPR) was utilized to characterize the reduction behavior and pulse CO chemisorption measurement was performed to characterize the number of active sites of the catalysts. Transmission electron microscopy (TEM) analysis was used to characterize metallic particle size distribution and extended X-ray absorption structure (EXAFS) measurements were performed to verify the bimetallic bond formation. The reactor evaluation results show that Co-Pt and Cu-Pt bimetallic catalysts exhibit much higher hydrogenation activity than the corresponding monometallic catalysts, and Co-Pt shows much higher selectivity toward C=O bond hydrogenation than Cu-Pt. The trend of hydrogenation activity and selectivity is consistent with previous studies of the hydrogenation of unsaturated aldehydes on model bimetallic surfaces. (C) 2012 Elsevier B.V. All rights reserved.