SiO2负载MoP催化剂的制备及其对苯甲醇选择性氧化的催化性能

Preparation and characterization of SiO2 supported-MoP catalyst and its catalytic performance for the selective oxidation of benzyl alcohol

摘要:

在SiO2载体上，以乙酰丙酮钼与次磷酸铵为原料，未经煅烧直接还原制备负载型磷化钼（MoP/SiO2）催化剂，通过XRD、N2-物理吸附、TEM和XPS等手段对催化剂进行表征。研究了浸渍液中P/Mo摩尔比（n(P):n(Mo)=1:1，2:1，3:1）、还原温度（500、550、600 ℃）对MoP相的影响，并考察其在苯甲醇选择性氧化生成苯甲醛反应中的催化性能。结果表明，浸渍液中P/Mo摩尔比为2、还原温度为550 ℃时，所获得的MoP/SiO2催化剂（MoP/SiO2-550-2）在苯甲醇选择性氧化生成苯甲醛反应中具有最好的转化率（99.7%）和优异的产物选择性（99.8%），这是由于MoP/SiO2-550-2催化剂上形成了更多小颗粒的MoP相。

Abstract:

SiO2-supported MoP (MoP/SiO2) catalyst was prepared by using molybdenum acetylacetonate and ammonium hypophosphite as raw materials through wetness impregnation method, which was reduced at high-temperature reduction without calcination, The obtained MoP/SiO2 catalyst was characterized by XRD, N2-physisorptions, TEM and XPS to study the effect of P/Mo mole ratios (n(P):n(Mo)=1:1,2:1,3:1) in impregnation liquid and reduction temperature (500,550,600 ℃) on the formation of MoP phase. Its catalytic performance in the selective oxidation of benzyl alcohol to benzaldehyde was further investigated. It was found that the prepared MoP/SiO2 catalyst with P/Mo mole ratio of 2 and the reduction temperature of 550 ℃ (MoP/SiO2-550-2) had the highest conversion （99.7%）and selectivity（99.8%）in the selective oxidation of benzyl alcohol to benzaldehyde, which is attributed to the formation of more and small MoP phases on the MoP/SiO2-550-2 catalyst.