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考察了银负载量及反应气预处理对银催化剂上CO选择氧化反应的影响 .结果表明 ,O2 转化率、CO的转化率及选择性都随着银负载量的增加而升高 ,CO氧化的选择性随着温度的降低而升高 ,低温下的选择性可达 70 %～ 80 % .CO TPR谱显示 ,产物CO2 脱附量及脱附温度的次序与CO选择氧化活性有一致的对应关系 .当反应气处理温度为 30 0℃时 ,催化剂上CO氧化活性最高 ;随着反应气处理温度的继续升高 ,CO氧化活性及选择性反而降低 .金属银的粒子尺寸随着银负载量的增加而增大 ;高温下反应气处理后 ,金属银粒子的尺寸明显减小 .催化剂上CO氧化活性及选择性与银粒子的大小及催化剂的表面结构有关
The effects of silver loading and reaction gas pretreatment on CO selective oxidation of silver catalysts were investigated.The results showed that the conversion of O2 and the conversion and selectivity of CO increased with the increase of silver loading. Selectivity increased with the decrease of temperature, and the selectivity was as low as 70% -80% at low temperature. The CO TPR spectra showed that the order of CO2 desorption and desorption temperature was consistent with the CO selective oxidation activity When the reaction gas temperature is 30 ℃, the oxidation activity of CO on the catalyst is the highest.With the increase of reaction gas temperature, the oxidation activity and selectivity of CO decrease but the particle size of metal silver decreases with the increase of silver loading Increases and increases; the size of the metallic silver particles decreases significantly after the reaction gas is treated at high temperature.The oxidation activity and selectivity of CO on the catalyst are related to the size of the silver particles and the surface structure of the catalyst