针对Co-Mn-Br-Zr催化剂氧化性强导致副产多的问题,以氧化性稍弱的Ni-Mn-Br-Zr为催化剂探究催化剂各组分摩尔比对偏三甲苯液相空气氧化生成偏苯三酸反应的影响,同时与Co-Mn-Br-Zr催化剂在相同条件下进行比较。结果表明,随着Ni、Mn摩尔分数的增大,偏三甲苯的转化率、偏苯三酸摩尔收率都有所提高,同时副产物苯二甲酸和均苯四酸的收率也随之增加;随着Br摩尔分数的增大,偏三甲苯转化率迅速增大,但偏苯三酸摩尔收率仅有略微增大;Zr摩尔量变化对反应几乎没有影响。在200℃、2.0 MPa、Ni(Co)∶Mn∶Br∶Zr摩尔比为1∶1∶1∶0.05、反应时间为80 min的条件下,Ni基催化剂下偏苯三酸的摩尔收率达到了56.60%,杂质酸收率为3.16%;优于Co基催化剂下偏苯三酸的摩尔收率54.85%和杂质酸收率3.66%。

To solve the problem that strong oxidizing ability of Co-Mn-Br-Zr catalyst leads to more by-products,Ni-Mn-Br-Zr catalyst with slightly weaker oxidizing ability is selected as a substitute.The effect of catalyst component content on the liquid-phase air oxidation of trimethylbenzene to trimeric acid is explored.Meanwhile,the activity of Ni-Mn-Br-Zr catalyst is compared with that of Co-Mn-Br-Zr catalyst under the same conditions.Study results show that with the increase of Ni and Mn molar fractions,both the conversion rate of trimethylbenzene and the yield of trimeric acid increase,but at the same time,the yields of phthalic acid and pyromellitic acid by-products also increase.As the molar fraction of Br increases,the conversion rate of trimethylbenzene increases rapidly,but the yield of trimethylbenzene increases slightly only.The change in Zr molar fraction has almost no impact on the reaction.Under the conditions including 200℃,2.0 MPa,1∶1∶1∶0.05 for Ni(Co)∶Mn∶Br∶Zr molar ratio,and 80 minutes of reaction time,the yield of trimeric acid over Ni-Mn-Br-Zr catalyst reaches 56.60%,and the yield of impurity acid is 3.16%,better than 54.85% and 3.66%,respectively by Co-Mn-Br-Zr.

唐明远(1998-),男,硕士生,研究方向为工业催化,1059155457@qq.com;王琪(1978-),男,博士,副教授,研究方向为工业催化,通讯联系人,wangqi@hfut.edu.cn。