均匀沉淀法制备Al_(2)O_(3)负载的铜基催化剂及其催化合成吗啉的研究

Preparation of copper⁃based catalyst supported on Al_(2)O_(3) by homogeneous precipitation method and its application in synthesis of morpholine

以尿素为沉淀剂,通过均匀沉淀法制备了Al_(2)O_(3)负载的铜基催化剂。利用XRD、SEM和H_(2)-TPR等手段对催化剂进行表征,并考察活性组分铜镍摩尔比、载体质量分数和尿素摩尔分数对其催化合成吗啉的影响。结果表明,铜镍摩尔比为3∶1、载体质量占催化剂质量的40%、尿素物质的量占金属硝酸盐物质的量的5.25倍时,所制备催化剂具有最高的催化性能。相比于商品催化剂,均匀沉淀法制备的催化剂具有更低的还原温度、更小的平均粒径、疏松的表面结构和优良的稳定性。

Copper⁃based catalyst supported on Al_(2)O_(3) is prepared via homogeneous precipitation method with urea as precipitator,and characterized by means of XRD,SEM and H_(2)⁃TPR.The effects of copper⁃nickel molar ratio,carrier mass fraction and urea molar fraction on the synthesis of morpholine are investigated.The results show that the catalyst has the highest catalytic performance when the molar ratio of copper⁃nickel is 3∶1,the support accounts for 40%of the total mass of the catalyst,and the amount of urea is 5.25 times that of metal nitrate.Compared with commercial catalyst,the catalyst prepared via homogeneous precipitation method has lower reduction temperature,smaller average particle size,loose surface structure and excellent stability.