Ni-Mo-O催化剂中协同作用对丙烷氧化脱氢的影响

在 Ni-Mo-O体系中 ,加入 Mo O3 能极大地提高丙烷氧化脱氢制丙烯的反应活性。选用固混法、沉淀法、柠檬酸法制备了 Mo O3 过量 1 5 % (摩尔分数 )的α -Ni Mo O4催化剂 ,其中用沉淀法制得催化剂在 5 0 0℃ ,V( C3 H8) /V ( O2 ) /V ( N2 ) =1 0 /1 0 /5 0 ,反应气流量为 70 m L/min的条件下丙烷转化率可达 38.7% ,丙烯选择性达 70 .1 4 %。经 XRD,XPS,TPR表征说明 ,在含有过量 Mo O3 的催化剂中 ,α -Ni Mo O4与 Mo O3 两种晶体之间可产生微小的相互吸引 ;从而发挥协同作用 ,是提高催化剂活性

SYNERGISTIC EFFECT OF Ni-Mo-O CATALYSTS IN OXIDATIVE DEHYDROGENATION OF PROPANE TO PROPENE

Three kinds of Ni Mo O catalysts were prepared by precipitation, mixing and citric acid decomposition methods. Although XRD patterns showed that all the three kinds of catalyst have almost the same crystal structure of α NiMoO 4 and MoO 3, XPS and TPR measurements provided evidence for the synergistic effects between α NiMoO 4 and MoO 3 phases in the catalyst prepared by precipitation method. using this catalyst in oxidative dehydrogenation of propane, the conversion of propane and the selectivity to propene were 38.7% and 70.1% respectively at 500 ℃, V(C 3H 8)∶V(O 2)∶V(N 2)=10∶10∶50 and gas flow 70 mL/min.