摘要
采用等体积浸渍法将Mo、W氧化物负载在USY分子筛上,并通过固体核磁共振、X射线衍射、N2吸附-脱附、NH3程序升温脱附和吡啶红外吸附等分析手段,研究了Mo、W氧化物的负载对USY分子筛结构及酸性的影响。结果表明,当Mo、W氧化物负载质量分数不大于8%时,USY分子筛骨架结构依然存在,但结晶度下降。Mo、W氧化物的负载造成了分子筛骨架脱铝;且随负载量的增加,分子筛脱铝的程度加深。负载Mo氧化物之后,USY分子筛的总酸量和L酸量增加;但随负载量的提高,总酸量和中强酸降低,B酸减少。负载量相同时,Mo氧化物对分子筛的作用大于W氧化物。
Mo or W oxide were supported on a series of USY zeolite by means of incipient-wetness impregnation method.The structures of Mo(W)/USY samples were characterized by XRD and N2 adsorption-desorption,and the influences of Mo and W oxides on the chemical states of Al,Si and acidities in USY were investigated by MAS NMR,NH3-TPD and Pyridine-IR.Compared with parent USY zeolite,the faujasite framework of Mo(W)/USY samples were retained,but the crystallinity reduced.The phenomenon of zeolite dealumination was found after Mo or W oxide loaded.Simultaneously,the total acid amount,Brnsted and Lewis acid sites in the samples were increased,which,however,were decreased with the increase of Mo oxide amount.Moreover,the influence of Mo oxide was more obvious than that of W oxide with the same amount.
出处
《石油学报(石油加工)》
EI
CAS
CSCD
北大核心
2011年第5期668-673,共6页
Acta Petrolei Sinica(Petroleum Processing Section)
关键词
USY分子筛
改性
钼、钨氧化物
酸性
USY zeolite
modification
molybdenum or tungsten oxide
acidity