Selective oxidation of benzyl alcohol over Pd/MnCeOx catalyst

• Main Author: Zheng, Hui Jian.
• Other Authors: Yang Yanhui
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Chemical engineering::Chemical processes
• Online Access: http://hdl.handle.net/10356/39841
• Institution: Nanyang Technological University

Benzyl alcohol aerobic selective oxidation to benzaldehyde over Pd /MnCeOx was investigated in this study. Method of loading metal catalyst to the support, the composition (structure) of the support, Pd loading amount are 3 important variables in the optimization of the catalyst. Their relationships with catalytic performance were studied to determine the best combination of these 3 variables, yielding the optimized catalysts. Results showed that 0.5 wt% Pd on crystalline MnCeOx (10Mn1Ce) and 0.5 wt% Pd on amorphous MnCeOx (7Mn3Ce) both loaded using microwave (MW) method displayed best activity and selectivity, with the latter being slightly more generic. Synergistic effect between MnOx and CeO2 in mixed MnCeOx support was demonstrated. It was also found that Pd is likely to be the only active species in the catalyst. Physical characterizations such as X-ray diffraction(XRD) and physisorption were done to study more about how structural parameters changes when the variables changed and how these parameter changes affect the catalytic performance. XRD showed that there is poorer pore distribution in amorphous support compared to crystalline and exact species of crystalline MnCeOx are CeO2, Mn3O4 and Mn2O3. Other findings include pore size effect was found to be significant in crystalline support while specific surface area effect significant in amorphous support and high metal loading tend to cause agglomeration of metal species, leading to lower activity.