The bimetallic Pd–Pt/Al₂O₃ supported catalysts with different Pd/Pt ratios have been prepared and studied in methane oxidation reaction. Comparison of their catalytic properties with those of monometallic Pd/Al₂O₃ and Pt/Al₂O₃ samples has shown that the bimetallic catalysts with a relatively low Pt loading (less than 0.4 mol%) are more active than the monometallic ones indicating the synergy effect. An increase in Pt loading above 0.5 mol% decreases the catalytic activity, so that these catalysts become less active than the monometallic Pd/Al₂O₃ catalysts, but still keep an activity higher than that of the least active monometallic Pt/Al₂O₃ sample. The chemical states of the palladium and platinum for all the catalysts produced depending on the reaction conditions have been investigated with in situ XPS. It has been shown that even at room temperature the reaction mixture affects the surface composition of the catalysts, which does not change much at higher reaction temperatures. The data have led us to suggestion that activity in the total methane oxidation is promoted by formation of Pd²⁺, surface fraction of which depends on Pt content in the bimetallic catalysts.

制备了具有不同Pd / Pt比的双金属Pd-Pt / Al ₂ O ₃载体催化剂，并进行了甲烷氧化反应研究。将它们与单金属Pd / Al ₂ O ₃和Pt / Al ₂ O ₃样品的催化性能进行比较表明，Pt含量较低（小于0.4 mol％）的双金属催化剂比单金属催化剂更具活性。协同效应。Pt负载量增加到0.5 mol％以上会降低催化活性，因此这些催化剂的活性低于单金属Pd / Al ₂ O _3。催化剂，但仍保持其活性高于最低活性的单金属Pt / Al ₂ O ₃样品的活性。已经使用原位XPS研究了根据反应条件生产的所有催化剂的钯和铂的化学状态。已经表明，即使在室温下，反应混合物也会影响催化剂的表面组成，在较高的反应温度下，其表面变化不会太大。数据使我们建议，通过形成Pd ²⁺可以促进甲烷总氧化中的活性，Pd ^2+的表面分数取决于双金属催化剂中Pt的含量。