甲烷在铕改性Mo/HZSM-5催化剂上的直接芳构化反应 Ⅰ.制备条件及反应性能的考察

STUDY ON METHANE AROMATIZATION OVER EUROPIUMMODIFIED Mo/HZSM5 CATALYSTⅠ. Preparation of the Catalyst and the Catalytic activity

研究了稀土元素Ｅｕ对Ｍｏ／ＨＺＳＭ－５催化剂催化甲烷芳构化反应的影响，发现适量的稀土元素Ｅｕ可提高催化剂的甲烷转化率及苯选择性，在１０２３Ｋ反应时，甲烷的转化率达１９．３％，苯的选择性达９７．５％，且铕的促进作用随硅铝比的增加而加强．失活催化剂经氢气吹扫后，其活性较初活性略有提高．积炭分析表明，铕加速了催化剂的积炭，且适量积炭对芳构化反应也具有促进作用．

Under nonoxidizing condition and different reaction temperatures and different space velocities, the conversion of methane aromatization over Eu modified Mo/HZSM5 catalyst was investigated. The results showed that appropriate quantity of Eu could considerably improve the activity of the catalyst and selectivity for benzene. The conversion of methane reached 193% and the selectivity for benzene was about 975% at 1023 K. The Mo/HZSM5(n(SiO2)/n(Al2O3)=25) catalyst showed better performance than Mo/HZSM5(n(SiO2)/n(Al2O3)=38) for methane aromatization. Deposited carbon on the catalyst was removed by hydrogen treatment at 1023 K, the catalyst being regenerated. Carbon accumulation on the catalyst was studied by means of TG method. It was demonstrated that Eu enhanced carbon deposition on the catalyst and appropriate quantity of deposited carbon improved the activity of the catalyst.