Cu0.5Zn0.5Cr0.5Al1.5O4尖晶石的制备及其催化性能

Preparation and Catalytic Properties of Cu0.5Zn0.5Cr0.5Al1.5O4Spinels

摘要:

以硝酸铜、硝酸锌、硝酸铬、硝酸铝和氢氧化钠为原料，利用化学共沉淀法制备铜锌铬铝尖晶石（Cu0.5Zn0.5Cr0.5Al1.5O4），并采用XRD、ICP、SEM和BET对其结构和物理、化学性质进行了表征。将不同组成的铜锌铬铝尖晶石作为催化剂在固定床反应器上催化合成了N-甲基-4-氨基苯甲醚(NMA)。考察了尖晶石组成、反应温度、空速(WHSV)和反应原料配比对催化剂催化性能的影响。结果表明：最佳反应条件为反应温度265℃，WSHV0.15h-1、甲醇与对氨基苯甲醚物质的量比3：1，Cu0.5Zn0.5Cr0.5Al1.5O4具有最佳的催化性能。对氨基苯甲醚单程转化率可达90.95%，NMA的选择性可达94.93%。

Abstract:

CuxZn1-xCr0.5Al1.5O4 spinels were prepared by chemical co-precipitation method using Cu(NO3)2, Zn(NO3)2,Cr(NO3)3,Al(NO3)3 and NaOH as raw materials. The structure, physical and chemical properties of spinels were characterized by XRD, ICP, SEM and BET. CuxZn1-xCr0.5Al1.5O4 spinels with different compositions were used as catalysts in the fixed bed reactors for the catalytic synthesis of NMA. The influence of such factors as spinel compositions, reaction temperature, space velocity (WHSV) and molar ratio of reaction raw materials on the catalytic reaction was investigated. The experimental results indicated that reaction temperature of 265℃, WHSV of 0.15h-1 and 3:1 molar ratio of methanol to PA was optimal reaction conditions, and Cu0.5Zn0.5Cr0.5Al1.5O4 had the best catalytic performance. The conversion per pass of PA and the selectivity of NMA were 90.95% and 94.93% respectively.