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以θ-Al2O3为载体,采用浸渍法制备了PdO/θ-Al2O3和PdO/CeO2/θ-Al2O3催化剂,比较了催化剂的CO氧化活性和热稳定性。运用X射线粉末衍射(XRD),程序升温还原(H2-TPR),拉曼光谱(Raman),CO化学吸附和物理吸附(BET)等技术对催化剂进行了表征。结果表明,PdO/θ-Al2O3催化剂经过1000℃焙烧后CO氧化活性较低;而PdO/CeO2/θ-Al2O3催化剂经过1000℃焙烧后CO氧化活性反而高于500℃焙烧的活性。CeO2能有效提高PdO/CeO2/θ-Al2O3催化剂的热稳定性,在10 h的稳定性实验中无失活现象发生。PdO/CeO2/θ-Al2O3-1000催化剂具有最高的转换频率(TOF=3.36 s-1)。
PdO / θ-Al2O3 and PdO / CeO2 / θ-Al2O3 catalysts were prepared by impregnation method using θ-Al2O3 as support, and the CO oxidation activity and thermal stability of the catalysts were compared. The catalysts were characterized by XRD, H2-TPR, Raman, CO chemisorption and BET. The results show that the catalytic activity of CO oxidation is lower when the PdO / θ-Al2O3 catalyst is calcined at 1000 ℃ than that of the PdO / θO2-Al2O3 catalyst after calcination at 1000 ℃. CeO2 can effectively improve the thermal stability of PdO / CeO2 / θ-Al2O3 catalyst and did not deactivate during the stability test of 10 h. The PdO / CeO2 / θ-Al2O3-1000 catalyst has the highest switching frequency (TOF = 3.36 s-1).