钾助剂对硼铝酸铜催化脱氢环化性能的影响

Effect of Potassium Promoters on Catalytic Performance of Copper Aluminum Borate for Dehydrocyclization of o-Ethylaniline

通过添加不同含量的K,考察了钾助剂对硼铝酸铜催化邻乙基苯胺脱氢环化制备吲哚的影响,并通过XRD、TPD、TPR、TG对催化剂进行了表征.结果表明,K助剂的加入中和了部分催化剂强酸中心,在一定程度上降低了催化剂表面酸性,但对催化剂表面积炭没有明显改善.钾助剂的添加提高了催化剂晶粒的分散度,并且与活性组分发生协同作用,改善了催化剂的脱氢反应性能.在空速为0.1 h-1、水油摩尔比为10∶1条件下,未添加K的催化剂上,邻乙基苯胺的转化率为45%左右,而添加了6.05%K的催化剂上,邻乙基苯胺的转化率提高到了60%以上.同时,钾助剂的添加延缓了铜氧化物的还原,减慢了催化剂失活的速度:未添加K的硼铝酸铜,反应80 h后,邻乙基苯胺的转化率由50%降至41.3%,而对应的修饰了6.05%K的催化剂,转化率却基本维持不变.

The effect of potassium promoters on the copper aluminum borate for dehydrogenation of o-ethylaniline to indole was investigated in self-made catalytic reactor. The crystal structure, surface acidity, reduction performance and carbon deposition were measured by XRD, TPD, TPR and TG. The results showed that the addition of potassium promoters did not change the structure of the catalyst, but it could neutralize strong acid center and improve the dispersity of crystal particles on the surface of the catalyst. Moreover, it could also bring about synergy with the active ingredients, improve the reactive performance of dehydrogenation. In the condition of which WHSV was 0. 1 h^-1 and mole ratio of water to o-ethylaniline is 10： 1, conversion of o-ethylaniline is about 45% on the K0%-Cu- AB, while the conversion of o-ethylaniline increased to 60% on the K6. 05%-CuAB. Meantime, it could delay the reduction of copper oxide, and slow down the speed of the catayst＇s deactivation ： Conversion of o-ethylaniline on the K0%-CuAB dropped from 50% to 41.3% , the conversion maintained unchanged on the K6. 05% -CuAB after reaction for 80 h.