机构地区: 四川大学化学学院化学系
出 处: 《天然气化工—C1化学与化工》 1995年第4期10-13,共4页
摘 要: 对比研究了不同还原温度下CO2与CO在Ni/Al2O3催化剂上的吸附行为。结果表明,在523K、573K、673K和723K还原后形成的Ni物种均是良好的CO吸附中心,且随着还原温度的升高,CO吸附量增大。但当还原温度升高至773K时,催化剂对CO的吸附能力急剧下降。对CO2而言,仅当催化剂经573K还原时可获得良好的CO2活化吸附中心,773K还原时则与CO的吸附相似,催化剂几乎丧失对CO2的吸附能力。不同的还原温度,不仅造成催化剂上吸附中心数目的改变,同时催化剂上吸附中心的性质也要发生变化。对CO2的活化吸附需要与CO不同的吸附中心。 he adsorption of CO and CO2 on Ni/Al2O3 catalyst at different reducing tempera tures is investigated comparatively. It is foundthat the nickel species formed by reducing thecatalyst at 523, 573, 673, and 723K act as favorable adsorption sites for CO, and the adsorbed CO amount increases with the reducingtemperatures. However, the adsorptive capacity of the catalyst for CO drastically decreaseswhen the reducing temperature rises up to773K. Only when reduced at 573K can thecatalyst exhibit better active adsorption capacity for CO2. Reduced at 773K, the catalyst almost loses its adsorbability for CO2. the sameas for CO. Variations of both the amount andcharacter of adsorption sites on the catalystwould occur at different reducing temperatures. The active adsorption sites for CO2 areneeded to be different froth those for CO.