摘要
研究了Hβ和SiO2负载磷钨酸催化剂对甲苯和均三甲苯歧化与烷基转移反应制备二甲苯的催化性能。结果表明:磷钨酸具有酸性强、低温活性高和二甲苯选择性高的特点,尤其是负载在SiO2上以后活性和稳定性有显著提高;磷钨酸负载在SiO2上以后,随着催化剂中磷钨酸含量的增加,均三甲苯转化率和二甲苯收率先增后减,当磷钨酸质量百分数为50%时,负载效果最好,440℃时均三甲苯的最大转化率为44.8%,420℃时二甲苯的选择性和收率的最大值分别为84.9%和34.8%。
H3 PW12O40 and H3 PW12O40 supported on Hβ or SiO2 were used in transalkylation and disproportionation of toluene with 1,3,5-trimethylbenzene to produce dimethylbenzene and the results were compared. Results showed that PW had a high acidity, which was able to promote effectively the alkylation and disproportionation reaction even at low temperatures and produce more dimethylbenzene. The activity and thermal stability of PW was increased remarkably when supported on SiO2. The conversion of 1,3,5-trimethylbenzene and the yield of dimethylbenzene first increased and then decreased when the PW loading was increased. The catalyst activity was the highest when PW loading was 50%, and the conversion of 1,3,5-trimethylbenzene was 44.8 % at 440 ℃. The selectivity was 84.9% and the yield was 34.8% at 420 ℃.
出处
《华东理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2008年第3期315-318,368,共5页
Journal of East China University of Science and Technology
关键词
杂多酸
磷钨酸
甲苯
均三甲苯
歧化
烷基转移
heteropoly acid
HaPW12 O40
toluene
1, 3, 5-trimethylbenzene
disproportionation
tansalkylation
