柠檬酸络合浸渍法制备的Ag-Mn/γ-Al_2O_3-TiO_2催化剂用于丙烷催化燃烧

采用不同浸渍方法制备了系列Ag-Mn/γ-Al_2O_3-TiO_2催化剂,利用BET、XRD、TEM、XPS和H_2-TPR等技术对催化剂进行了表征,通过丙烷催化燃烧反应考察了催化性能。结果表明,与常规浸渍法相比,柠檬酸络合浸渍法促进了催化剂表面Ag与Mn颗粒的分散及加强了Ag与Mn之间的相互作用,从而提高了活性氧物种的相对含量和催化剂的低温还原性能,进而促进丙烷催化燃烧活性的提升。其中,络合浸渍法制备的Ag_1Mn_3/γ-Al_2O_3-TiO_2催化剂在263℃时丙烷转化率即可达90%。

Preparation of Ag-Mn/γ-Al2O3-TiO2 catalysts by complexation-impregnation process with citric acid and its application in propane catalytic combustion

A series of Ag-Mn/γ-Al₂O₃-TiO₂ catalysts were prepared by different impregnation procedures. The catalysts were characterized by BET, XRD, TEM, XPS and H₂-TPR, and the catalytic properties were investigated by propane catalytic combustion. Results show that compared with the conventional impregnation method, complexation-impregnation procedure with citric acid promotes the dispersion of Ag and Mn particles on the surface of catalyst and strengthens the interaction between Ag and Mn, so as to increase the relative content of reactive oxygen species and improve the reducibility of catalysts, which further improves the catalytic activity of propane combustion reaction. Especially, the Ag₁Mn₃/γ-Al₂O₃-TiO₂ catalyst prepared by complexation-impregnation process with citric acid exhibits the best activity for propane catalytic combustion with 90% conversion at 263℃.