Preparation Of CuO-substrate Composite Oxide Catalysts And Their Catalytic Activities For CO Oxidation At Low Temperature

In this thesis, the preparation and properties of the non-noble metal catalysts with high stability were studied for CO oxidation reaction at low temperature. N2 adsorption-desorption, XRD, H2-TPR, CO-Pulse, CO-TPR, CO-TPD, EPR and so on were used to characterize the physicochemical properties of CuO-substrate catalysts (Cu-Ce-O and Cu-Mn-O) and the influences of doping a third component on the properties of catalysts. The followings are the major findings.The results show that, the catalytic activity of Cu-Ce-O catalyst decreased when doped with Mn or Ni. However, when Fe was doped in the Cu-Ce-O catalyst, its catalytic activity was improved largely. When the loading of Fe reached x=1, marked Cu1Ce8Fe1-O, its crystallite size was decreased from 7.8 nm to 5.2 nm and BET surface area was increased from 120 m2g-1 to 164 m2g-1 The presence of Fe in Cu1Ce8Fe1-O promotes obviously the performance of the catalyst surface oxygen species, resulting in an increase of its catalytic activity for the CO oxidation at low temperature.The influences of Cu/Ce ratio and preparation conditions (the calcination atmosphere and time, citric acid and pretreatment, etc.) on the Cu1Ce8Fe1-O properties were very obvious. The Cu1Ce8Fe1-O catalyst calcinated in N2 at 600℃for 2h, and then calcinated in air at 400℃for 2h, finally pretreated by 20%O2/He, exhibits good catalytic activity, such as its T90 for CO oxidation is 50℃.The influences of the calcination temperature, precipitant and composition on the catalytic activity of Cu-Mn-0 catalyst were investigated. The results show that, the catalyst prepared with the ratio of copper and manganese at 8:2 and ammonia as precipitant, and then calcinated at 300℃, exhibits higher catalytic activity for CO oxidation, such as its T90 is 68℃.