The shape effect of La2O2CO3 in Pd/La2O2CO3 catalyst for selective hydrogenation of cinnamaldehyde

Controllably adjusting the morphology of nanocatalysts is known as an effective way to improve catalytic performance. Pd/La2O2CO3 catalysts with different morphologies (nanorods and nanoparticles) were successfully synthesized via simple hydrothermal method and evaluated for selective hydrogenation of cinnamaldehyde. The highly catalytic activity (86% HCAL selectivity at 100% CAL conversion at 3 h) occurred over Pd/La2O2CO3-NRs with La2O2CO3 nanorods as support. Remarkably, Pd/La2O2CO3-NRs catalyst not only showed better catalytic performance, nearly 10 times higher than Pd/La2O2CO3-NPs catalyst, but also exhibited excellent cycling stability. CO2-TPD showed that the intense desorption peaks at about 560 K represented the medium strength basic sites (La3+-O2- pairs) with a total amount of 0.13 mmol g(-1) on the La2O2CO3-NPs and 0.21 mmol g(-1) on the La2O2CO3-NRs. These results indicated that support morphology has a significant effect on catalytic activity and can modify surface basicity, which resulting in enhanced hydrogenation activity.