Nowicka Ewa, Althahban Sultan, Leah Tom D, Shaw Greg, Morgan David, Kiely Christopher J, Roldan Alberto, Hutchings Graham J
Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff, UK.
Department of Materials Science and Engineering, Lehigh University, Bethlehem, PA, USA.
Sci Technol Adv Mater. 2019 Apr 25;20(1):367-378. doi: 10.1080/14686996.2019.1598237. eCollection 2019.
Pd-Zn/TiO catalysts containing 1 wt% total metal loading, but with different Pd to Zn ratios, were prepared using a modified impregnation method and tested in the solvent-free aerobic oxidation of benzyl alcohol. The catalyst with the higher Pd content exhibited an enhanced activity for benzyl alcohol oxidation. However, the selectivity to benzaldehyde was significantly improved with increasing presence of Zn. The effect of reduction temperature on catalyst activity was investigated for the catalyst having a Pd to Zn metal molar ratio of 9:1. It was found that lower reduction temperature leads to the formation of PdZn nanoparticles with a wide particle size distribution. In contrast, smaller PdZn particles were formed upon catalyst reduction at higher temperatures. Computational studies were performed to compare the adsorption energies of benzyl alcohol and the reaction products (benzaldehyde and toluene) on PdZn surfaces to understand the oxidation mechanism and further explain the correlation between the catalyst composition and its activity.
采用改进的浸渍法制备了总金属负载量为1 wt%但钯锌比例不同的Pd-Zn/TiO催化剂，并在无溶剂有氧氧化苯甲醇反应中进行了测试。钯含量较高的催化剂对苯甲醇氧化表现出更高的活性。然而，随着锌含量的增加，对苯甲醛的选择性显著提高。针对钯锌金属摩尔比为9:1的催化剂，研究了还原温度对催化剂活性的影响。结果发现，较低的还原温度导致形成粒径分布较宽的PdZn纳米颗粒。相反，在较高温度下还原催化剂时会形成较小的PdZn颗粒。进行了计算研究，以比较苯甲醇及其反应产物（苯甲醛和甲苯）在PdZn表面的吸附能，从而了解氧化机理，并进一步解释催化剂组成与其活性之间的相关性。
