Selective hydrogenation of cinnamaldehyde using Pd catalysts supported on Mg/Al mixed oxides: Influence of the Pd incorporation method

Abstract

A series of hydrotalcite-like compounds was synthesized by varying Mg/Al molar ratio with values of 2, 3, and 4. After thermal treatment at 823 K, the corresponding mixed oxides were obtained and used as catalytic supports. The incorporation of a Pd metallic phase (0.5 g/g loading), was carried out by two methods: 1) in situ vapour phase thermal decomposition, and 2) impregnation by organic method. Fresh and calcined samples were characterized by XRD and N 2 sorption experiments. The basic and metal functions were analyzed by CO 2 -TPD and H 2 -TPR. The Pd-support interaction was studied by FTIR spectroscopy using CO as a probe molecule while the morphology of Pd nanoparticles on the catalysts was studied by SEM, HRTEM, and theoretical simulation using the Fast Fourier Transform (FFT) method. Finally, the catalytic activity results showed a higher conversion towards hydrocinnamaldehyde in the cinnamaldehyde hydrogenation reaction for the catalysts prepared by vapour phase thermal decomposition, compared with those prepared by organic method, showing the significant dependence on the catalytic activity and the Pd incorporation method.

Pd Nanoparticles Supported on Triangle‐Shaped La2O2CO3 Nanosheets: A New Highly Efficient and Durable Catalyst for Selective Hydrogenation of Cinnamaldehyde to Hydrocinnamaldehyde

“…The Pd/La 2 O 2 CO 3 ‐TNS catalyst exhibits a TOF of 41 238 h −1 in contrast to 1251 h −1 for the Pd/La 2 O 2 CO 3 ‐NR. This is one of the highest activities for reported heterogeneous hydrogenation catalysts, such as Pd@TNT, Pd‐NMC, PdWN/SBA‐15, and so on . This result indicated that the morphology effect of the La 2 O 2 CO 3 support can modify the reaction rate of CAL hydrogenation.…”