Physicochemical properties of Pd/Al₂O₃-TiO₂ catalysts with different amounts of TiO₂ contents were investigated by XRD, nitrogen adsorption-desorption, FTIR, NH₃-TPD, H₂-TPR and XPS techniques. Catalysts of different compositions were tested in the ethanol oxidation reaction to study the effects of TiO₂ contents. Double peaks and symmetric path phenomena were observed at certain temperatures with the increase in TiO₂ contents. The symmetric peak phenomena and the diverse activity fluctuations have been ascribed to the controlling factors such as temperature and compositions. With the increase in TiO₂ content, the surface area, adsorbed oxygen contents and surface acid quantity decreased gradually. The large surface area and adsorbed oxygen contents were conducive to the performance, while increased acid amounts were not beneficial for ethanol oxidation. At 150 and 175 °C, Pd/AT(X¹) (X < 50) catalysts performed better in ethanol oxidation because of the main factors of surface area and adsorbed oxygen. Owing to the stronger effects of acid quantity compared to other factors, Pd/AT(X) (X < 50) catalysts showed lower catalytic performance at 200 and 225 °C. The higher contents of low-temperature acid in the NH₃-TPD results and the larger difference between Pd⁰ and Pd²⁺ in XPS analyses were the origins of the double peaks of higher activity for the Pd/AT20 and Pd/AT80 catalysts.

通过XRD，氮吸附-解吸，FTIR，NH ₃ -TPD，H ₂ -TPR和XPS技术研究了不同TiO ₂含量的Pd / Al ₂ O ₃ -TiO ₂催化剂的理化性质。在乙醇氧化反应中测试了不同组成的催化剂，以研究TiO ₂含量的影响。随着TiO ₂含量的增加，在一定温度下观察到双峰和对称路径现象。对称峰现象和各种活性波动已归因于诸如温度和组成的控制因素。随着TiO ₂的增加含量，表面积，吸附氧含量和表面酸量逐渐降低。大的表面积和吸附的氧含量有利于性能，而增加的酸量不利于乙醇氧化。在150和175°C下，由于表面积和吸附氧的主要因素，Pd / AT（X ¹）（X <50）催化剂在乙醇氧化中的表现更好。与其他因素相比，由于酸量的影响更大，因此Pd / AT（X）（X <50）催化剂在200和225°C下显示出较低的催化性能。NH ₃ -TPD中的低温酸含量越高，Pd ⁰和Pd ²⁺之间的差异越大 在XPS分析中，Pd / AT20和Pd / AT80催化剂具有更高活性的双峰起源。