【摘要】 制备贵金属低温催化氧化甲醛催化剂,研究了催化剂结构特征及催化氧化甲醛机理,并考察了催化剂性能。采用沉积-沉淀法制备负载型贵金属低温催化氧化甲醛催化剂,优化组成及制备条件,采用XRD、FT-IR、H₂-TPR、拉曼等对催化剂进行表征分析。催化剂最佳制备条件:NaOH为沉淀剂,载体n（Cu）/n（Mn）摩尔比为1∶2,Pt负载量（质量分数）为1%,载体制备pH为9—10,贵金属负载pH为9.5。Pt₁/Cu_0.5Mn催化剂以非化学计量比Cu_0.9Mn_1.8O₄无定形态晶体特征峰存在,Pt金属在载体表面分布均匀,且贵金属与载体相互作用使催化剂表面氧缺位浓度增加,表面活性氧物种增多,催化剂在室温下表现出良好的稳定性和重复性。室温下甲醛和氧气在催化剂表面共吸附,甲醛首先被催化剂表面活性氧氧化为DOM,由于DOM很活跃,在催化剂上很快被表面氧氧化成甲酸根,甲酸根在催化剂表面氧和气相氧的共同作用下氧化生成CO,最终被完全氧化为CO₂。其中甲酸盐物种向CO转化步骤是整个反应的速控步骤。更多还原

【Abstract】 A serious of noble metal catalysts for the oxidation of formaldehyde at low temperature was prepared. The structural characteristics and catalytic oxidation mechanism of formaldehyde of the catalysts were studied. The catalysts were prepared by a precipitation method and characterized by XRD, FT-IR, H₂-TPR, Raman spectroscopy. The results show that the Pt/CuMn catalysts exhibited high activity and the best preparation conditions are as follows: NaOH as precipitation agent, Cu/Mn ratio of carrier is 1 ∶2, Pt load（mass fraction） of 1%, carrier precipitation pH is 9-10, catalyst preparation pH is 9.5. The main phases of Pt1/Cu0.5 Mn catalyst were Cu_0.9Mn_1.8O₄ under the preparation conditions, Pt uniform distribution in the surface of carrier and the surface reactive oxygen species of the catalyst was promoted by the synergetic effect of Pt and carrier as well as the catalytic activity, the catalyst showed good stability and repeatability at room temperature. It was found that formaldehyde could be oxidized to DOM first by surface reactive oxygen species when formaldehyde and oxygen adsorption to the catalyst surface together, and then DOM will be oxidized to formate quickly, formate be oxidized to CO and CO₂ completely by surface reactive oxygen and gas phase finally, and the decomposition of formate was the key step in the whole reaction.更多还原