助剂和制备方法对V_2O_5/Al_2O_3催化性能的影响

Influence of Additives and Preparation Methods Influence on the Catalytic Properties of V_2O_5/Al_2O_3 Catalysts

用浸渍法制备了负载型MxOy-V2O5/Al2O3催化剂,同时考察了不同的制备方法对MoO3-V2O5/Al2O3催化剂的性能影响。用BET、H2-TPR、TPD平衡法等考察了催化剂的比表面积、氧化还原性能、表面氧脱附性能,结果表明,添加变价助剂Mo、Fe和Cr氧化物会增加供氧数目,提高α-蒎烯转化率。MoO3-V2O5/Al2O3催化剂表面O 2-和O-物种较多,活性也较好,桃金娘烯醛收率较高。MoO3-V2O5/Al2O3催化剂的制备方法影响其催化性能,表面化学改性法制备的催化剂表面具有较多O2-和O-物种,有利于催化剂的活性提高,α-蒎烯的转化率达88.9%,桃金娘烯醛的收率为79.1%。

MxOy-V2O5/Al2O3 catalysts were prepared by method of impregnation.The effect of different preparation methods on the catalytic properties of MoO3-V2O5/Al2O3 was investigated.The surface area,redox properties and the oxygen desorption behavior of the catalysts were characterized by BET,H2-TPR and TPD-MS.The analysis of the adopted catalysts shows that the MoO3-V2O5/Al2O3,Fe2O3-V2O5/Al2O3 and Cr2O3-V2O5/Al2O3 presented a higher number of surface oxygen and conversion rates of α-pinene,more O-2 and O-species exist on the surface of MoO3-V2O5/Al2O3 catalyst,the O-2 and O-species can increase catalytic activity and the yield of myrtenal.The different preparation methods have influence on the catalytic performance of MoO3-V2O5/Al2O3 catalysts;the surface modification method can generate more O-2 and O-species,which is propitious to improving the catalytic activity.Under such condition,the conversion rate of α-pinene is 88.9%,and the yield of myrtenal is 79.1%.