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用浸渍法制备了一系列以各种分子筛为载体、银及氧化钼为活性组分的负载型催化剂。在以分子氧为氧化剂 ,且原料气中不添加任何抑制剂的情况下 ,采用微反 色谱联合装置考察了催化剂对丙烯气相一步氧化制环氧丙烷的催化性能。结果表明 ,Ag含量、反应温度、载体及助剂对催化剂环氧化性能的影响非常明显。以MCM 4 1为载体的Ag MoO3 催化剂具有较好的催化性能 ,在 30 0℃下 ,环氧丙烷的选择性和氧气的转化率可分别达到 5 5 4 %和 2 2 % ;另外 ,0 1 %NaCl改性的 2 0 %Ag5 %MoO3 NaZSM 5催化剂在 35 0℃下 ,环氧丙烷的选择性从未改性的 9 1 %提高到 34 7%。
A series of supported catalysts with various molecular sieves as support and silver and molybdenum oxide as active components were prepared by impregnation method. In the presence of molecular oxygen as oxidant and without adding any inhibitor to the feed gas, the catalytic performance of the catalyst for propylene oxide gas-phase one-step oxidation of propylene oxide was investigated by a micro-chromatography combined device. The results show that the effect of Ag content, reaction temperature, carrier and additives on the epoxidation performance of the catalyst is very obvious. The catalytic activity of Ag MoO3 with MCM 4 1 as a carrier has good catalytic performance. The selectivity of propylene oxide and the conversion of oxygen can reach 55.4% and 22% respectively at 30 0 ℃. In addition, The% NaCl-modified 20% Ag5% MoO3 NaZSM5 catalyst increased the propylene oxide selectivity from 35% unmodified to 34.7% at 350C.