Ce改性CuZnAl催化剂上仲丁醇脱氢制备甲乙酮

Performance of Ce-modified CuZnAl catalyst in the dehydrogenation of sec-butanol to methyl ethyl ketone

采用共沉淀法制备了CuZnAl催化剂,并通过浸渍法将不同含量Ce引入到CuZnAl催化剂中,将其用于仲丁醇(SBA)脱氢制甲乙酮(MEK),研究了Ce改性对其催化性能的影响。结果表明,Ce的引入可以促使CuZnAl催化剂中Zn物种和Al物种发生反应,生成尖晶石(CuAl2O4)结构,有利于提高其催化稳定性;同时引入Ce能降低催化剂晶粒尺寸、提高CuO和ZnO的分散度,并使催化剂中Cu^2+含量提高、还原温度降低、还原后催化剂中活性组分CuO含量增加。Ce改性后的8%-Ce-CuZnAl催化剂对仲丁醇脱氢具有良好的活性,在240℃、质量空速为5 h−1的条件下,SBA转化率达91.4%,MEK收率为87.74%;而且在100 h内催化活性稳定,SBA转化率保持在92%左右、MEK收率保持在88%左右。

The CuZnAl catalyst prepared by co-precipitation was further modified with different contents of Ce through impregnation and used in the dehydrogenation of sec-butanol(SBA)to methyl ethyl ketone(MEK);the effect of Ce modification on the performance of CuZnAl catalyst was investigated.The results illustrate that the introduction of Ce in CuZnAl can promote the formation of CuAl2O4 spinel and thus improve the stability of Cemodified CuZnAl catalyst;meanwhile,Ce is also conducive to reducing the grain size,enhancing the dispersion of CuO and ZnO,lowering the reduction temperature,and increasing the content of Cu^2+ and consequently the content of active Cu0 species upon reduction.Over the Ce-modified 8%-Ce-CuZnAl catalyst,the conversion of SBA reaches 91.4% under 240℃ and a mass space velocity of 5 h−1,with a selectivity of 96% to MEK;during the 100 h reaction test,the SBA conversion keeps at about 92%,with the selectivity to MEK at about 96%,demonstrating excellent stability of the Ce-modified CuZnAl catalyst.