Abstract In this study, 1 wt.% Pd/Al2O3 sphere catalysts were prepared using the wet-impregnation (WI) and deposition-precipitation (DP) method using palladium chloride and tetraamminepalladium (II) nitrate as salt precursors. All catalysts were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier-transform infrared (FTIR) spectroscopy. The catalytic activity in toluene oxidation under gas-phase conditions was measured. The obtained results showed that metal dispersion and catalytic activity were strongly dependent on the salt precursor and method of catalyst preparation. The use of tetraamminepalladium (II) nitrate as the precursor presented smaller particle size, an enhanced dispersion and higher specific surface area. Moreover, the catalyst prepared with this precursor also showed higher catalytic activity than that prepared with palladium chloride. At 1 wt.% Pd loading, complete oxidation of toluene was achieved at 250°C. However, there was only approximately 80–90% efficient at the same temperature when the catalyst was prepared with palladium chloride as the precursor.

中文翻译：

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氧化铝球催化剂负载钯纳米粒子低温催化氧化甲苯：钯前驱体的影响及制备方法

摘要 在本研究中，以氯化钯和硝酸四氨合钯 (II) 为盐前体，采用湿浸渍 (WI) 和沉积-沉淀 (DP) 法制备了 1 wt.% Pd/Al2O3 球形催化剂。使用 X 射线衍射 (XRD)、透射电子显微镜 (TEM) 和傅里叶变换红外 (FTIR) 光谱对所有催化剂进行表征。测量了气相条件下甲苯氧化的催化活性。所得结果表明金属分散和催化活性强烈依赖于盐前体和催化剂制备方法。使用硝酸四氨合钯 (II) 作为前体表现出更小的粒径、增强的分散性和更高的比表面积。而且，用这种前体制备的催化剂也表现出比用氯化钯制备的催化剂更高的催化活性。在 1 wt.% Pd 负载下，甲苯在 250°C 下完全氧化。然而，当以氯化钯为前驱体制备催化剂时，在相同温度下只有大约 80-90% 的效率。