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用程序升温还原 ( TPR)、程序升温脱附 ( TPD)、X射线粉末衍射 ( XRD)及透射电子显微镜 ( TEM)等法对分步浸渍法制备的一系列 Mo-Ni/ γ-Al2 O3甲烷化催化剂的结构进行了表征 .考察了浸渍液的 p H值、焙烧温度及还原温度对催化剂的表面结构的影响 .结果表明∶先浸 Mo时 ,调 ( NH4 ) 6Mo7O2 4 溶液的 p H=3、浸 Mo后 50 0℃焙烧的催化剂易于还原 ,而且能抑制后浸 Ni时 ,难还原铝酸盐的形成 ;浸 Ni时 ,调 Ni( NO3) 2 溶液的 p H=8,浸后 4 30℃焙烧的催化剂易于还原 ;浸 Mo后 ,650℃焙烧易形成难还原的 Al2 ( Mo O4 ) 3,浸 Ni后 530℃焙烧的催化剂易形成难还原的 Ni Al2 O4 与类 Ni Al2 O4 铝酸盐 .催化剂于 50 0℃还原时 ,还原态的 Ni最多 ,4 50℃还原时有利于 Mo-Ni合金的形成
A series of Mo-Ni / γ-Al 2 O 3 methane catalysts prepared by the stepwise impregnation method were investigated by temperature programmed reduction (TPR), temperature programmed desorption (TPD), X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) The effects of p H value, calcination temperature and reduction temperature on the surface structure of the catalysts were investigated. The results show that the p H of the (NH4) 6Mo7O2 4 solution , The catalyst calcined at 500 ℃ after Mo impregnation is easy to reduce, and the formation of aluminate is inhibited when it is immersed in Ni. When Ni is immersed in Ni, the pH of Ni (NO3) 2 solution is adjusted to 8, ℃ calcined catalyst is easy to reduce. After Mo impregnation, it is easy to form refractory Al2 (MoO4) 3 when it is calcined at 650 ℃, and the catalyst calcined at 530 ℃ after Ni impregnation is easy to form Ni Al2 O4 and NiAl2O4 aluminate When the catalyst is reduced at 50 ℃, the maximum amount of Ni is reduced, which is beneficial to the formation of Mo-Ni alloy when it is reduced at 450 ℃