SBA-15负载磷化镍催化剂对喹啉加氢脱氮反应网络的影响

Effect of SBA- 15-supported nickle phosphate catalyst on hydrodenitrogenation network of quinoline

以介孔分子筛SBA-15为载体,采用等体积浸渍法,制备了Ni/P比为1.25的磷化镍催化剂,并对不同担载量的磷化镍催化剂进行了表征,表征结果显示催化剂表面的活性相主要是Ni2P,催化剂仍保留着载体所具有的介孔结构形式。采用碱性氮化物喹啉为模型化合物进行加氢实验,利用10 m L固定床加氢装置对制备出的催化剂进行了评价,结果表明:磷化镍催化剂加氢能力高于硫化态催化剂,能将大部分喹啉优先加氢饱和成十氢喹啉,降低了1,2,3,4-四氢喹啉转化为邻丙基苯胺的比例,降低了由于竞争吸附对反应性的抑制,从而提高了喹啉的脱氮反应活性,加快了反应的进行;考察了催化剂对喹啉加氢反应路径选择性的影响,喹啉加氢脱氮产物主要为丙苯与丙基环己烷,磷化镍催化剂条件下丙基环己烷占91.6%,丙苯占4.9%。

Mesoporous molecular sieve SBA-15 was used as a support to prepare nickel phosphide catalyst by incipient impregnation method, the Ni/P ratio was 1.25, the catalysts with different loads of nickel phosphate were characterized. The results show that the catalyst had the mesoporous structure which was similar to SBA-15, but with the gradual increase of loading, the orderliness of the mesoporous structure gradually weakened, the specific surface area, pore volume and pore size of the catalyst were decreased. Quinoline was used as a model compound to carry out a hydrogenation experiment, the catalyst was evaluated by a 10 mL fixed bed hydrogenation unit, the results show that the nickel phosphide catalyst for hydrogenation is higher than sulfided catalyst, most of quinoline could be changed into decahydroquinoline preferentially according to hydrogenation saturation which could reduce the proportion of 1, 2, 3, 4-tetrahydroquinoline to p-propyl aniline, reduce the inhibition of reaction by competitive adsorption. The inhibition of reactivity caused by competitive adsorption is decreased, thus the quinoline hydrodenitrogenation reaction activity is improved and the reaction rate is accelerated. The effect of the catalyst on the route selectivity during the quinoline hydrogenation process is investigated. The main products of the quinoline hydrodenitrogenation are propyl benzene and propyl cyclohexane. Under the conditions of nickel phosphate catalyst, propyl cyclohexane accounts for 91.6%, and propyl benzene accounted for 4.9%. © 2015, China Coal Society. All right reserved.