摘要
研究了ZSM-5中不同SiO_2/Al_2O_3比,不同改性元素以及调变HZSM-5表面酸对丙烷转化生成芳烃的活性和选择性的影响。结果表明:低SiO_2/Al_2O_3比对生成芳烃有利,但适当降低HZSM-5的强酸中心可抑制甲烷生成,提高生成芳烃的选择性。较好的改性元素是Zn、Ga、Pt及其双组分改性,另外也提出了改性元素如Ga,Zn等高选择性地生成芳烃是因它们在高温下可使丙烷直接脱H而活化的观点。
The effects of SiO_2/Al_2O_3 ratio, modifying element and surface acidity of HZSM-5 on the activity and selectivity of the catalyst for the conversion of propane to aromatios were studied. The conclusion is: low SiO_2/Al_2O_3 ratio improves the yield of aromatics, and reducing the density of strong acid centers improves the aromatic selectivity by inhibiting the production of methane. It can be seen from the study of ZSM-5 catalyst modified by various elements that besides Zn, Ga and Pt, Re in ⅦB and Cr in ⅥB also give good results. The former helps in the activation of propane, and the latter improves the selectivity to aromatics. Dual elements such as Zn-Pt, Ga-Pt, Zn-Pd etc. as modifiers for ZSM-5 catalysts can improve the selectivity of propane to aromatics. Experimental results from Ga modified catalysts with various acidity show that prop(?)ne is readily activated and dehydrogenated to propylene by Ga centers at higher temperature. Basd on results obtained with HZSM-5 catalysts of different acidity, the process of propane conversion has also been discussed.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
1991年第2期126-134,共9页
Journal of Fuel Chemistry and Technology
关键词
芳烃
丙烷
分子筛
镓
改性
aromatization
propane
ZSM-5
Gallium
