添加Ru的Mo/HZSM-5催化体系上的甲烷无氧脱氢芳构化

研究了在Ｍｏ／ＨＺＳＭ５催化剂中添加过渡金属阳离子以改变催化剂的反应性能，提高甲烷无氧脱氢芳构化的反应活性和稳定性．在添加第二组分的催化剂中，ＭｏＲｕ／ＨＺＳＭ５具有最佳的反应活性和稳定性．Ｒｕ的加入使甲烷的转化率由原来的６％～７％提高到９８％．采用比表面积及孔分布测定，Ｘ射线衍射，程序升温还原，程序升温氨脱附和差热分析等表征方法研究了ＭｏＲｕ／ＨＺＳＭ５催化剂的物理化学性质．结果表明，Ｒｕ的加入引起Ｍｏ／ＨＺＳＭ５催化剂强酸酸量的下降，并促进了Ｍｏ物种的还原．

THE EFFECT OF Ru ON THE DEHYDROGENATION AND AROMATIZATION OF METHANE IN THE ABSENCE OF OXYGEN OVER Mo/HZSM 5 CATALYSTS

The effect of adding second metal cation to Mo/HZSM 5 catalysts on the performance of dehydrogenation and aromatization of methane in the absence of oxygen was studied by means of XRD, TPR, NH 3 TPD and DTA. The results show that Ru is the best promoter among the tested transition metal cations. The Mo Ru/HZSM 5 catalyst gives a conversion of about 10% and a selectivity for aromatics of above 90% and shows better stability. The catalysts with Ru loading from 0 3% to 0 7% have better catalytic performances. The study of NH 3 TPD shows that the addition of Ru to Mo/HZSM 5 causes a decrease in amount of strong acid sites. TPR and DTA experiments demonstrate that the exsistence of Ru promotes the reduction of Mo species.