采用等体积浸渍法制备了一系列负载型Pd＋M(M＝MgO、CaO、SrO、BaO )催化剂，运用BET、CO-化学吸附、XRD、H2-TPR 和 XPS 等表征手段对催化剂进行了表征，并考察其对甲醇的催化氧化性能.结果表明，添加碱土金属可使 Pd 粒子高度分散，催化剂表面易还原氧物种量增多，还原速率加快；XPS分析可知，碱土金属可增强 Pd-Ce 间相互作用，促使Pd向氧化态过渡，同时增加催化剂表面 Ce3＋浓度，改善催化剂的氧化还原性能，进而提高催化剂的催化活性.助催化效果递变规律为 BaO＞CaO＞MgO＞SrO.
A series of Pd+M(M=MgO,CaO,SrO,BaO)catalysts was prepared by impregnation method.Specif-ic surface area measurements (BET),CO-chemisorption,X-ray diffraction (XRD),H2-temperature-pro-grammed reduction (H2-TPR),were used to characterize the effect of alkaline earth metal on the physicochemi-cal properties of the catalysts.Their catalytic activity towards methanol oxidation was evaluated.The results show that the addition of alkaline earth metal increases palladium highly dispersed and enhances the amount of active oxygen.X-ray photoelectron spectroscopy (XPS)result shows that the electron effects between Pd and support was improved.It was favorable for maintaining Pd in a higher oxidized state and increasing the concen-tration of Ce3+on the catalyst surface,which led to a better redox property.The excellent redox property helped to improve the catalytic activities toward methanol over Pd-based catalysts.The aid catalytic activity was follow-ing the order:BaO>CaO>MgO>SrO.
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