Sulfur Resistance and Activity of Pt/CeO2-ZrO2-La2O3 Diesel Oxidation Catalysts

Three Pt/CeO2-ZrO2-La2O3 diesel oxidation catalysts were prepared by two different routes and characterized by X-ray diffraction, N2 adsorption, temperature-programmed reduction, temperature-programmed desorption, X-ray photoelectron spectroscopy, and infrared spectroscopy. The synthesis procedure affected the structure, texture, sulfur resistance, and catalytic activity of the catalysts. Sulfur poisoning increased the light-off temperature of all the catalysts, but the Pt/CeO2-ZrO2-La2O3 catalyst prepared by depositing ZrO2 and La2O3 on the surface of CeO2 nanoparticles exhibited better sulfur tolerance and catalytic activity with simulated diesel emission due to the high dispersion of Pt on CeO2-ZrO2-La2O3 oxide with a Zr-rich surface.

摘要：采用两种方法制备了三种 Pt/CeO2-ZrO2-La2O3 柴油车尾气氧化催化剂, 并用 X 射线衍射、N2 物理吸附、程序升温还原、程序升温脱附、X 射线荧光光谱和红外光谱等方法对其进行了表征. 结果发现, 制备方法对催化剂的结构、织构、抗硫性能及催化性能的影响非常大. 对其进行硫中毒, 导致起燃温度明显升高. 将 ZrO2 和 La2O3 沉积在 CeO2 表面所制得的 Pt/CeO2-ZrO2-La2O3 催化剂表现出更高的抗硫及催化氧化性能, 这主要归功于 Pt 在富 Zr 载体表面具有更高的分散性.

The Pt loaded on CeO2-ZrO2-La2O3 prepared by deposition-precipitation methods (a and b) exhibits excellent sulfur tolerance and catalytic activity compared to co-precipitation methods (c and d) due to the better dispersion.Figure optionsDownload as PowerPoint slide