The morphology effect of tungsten oxide on the NH₃-SCR activity of the supported CeO₂ catalyst was experimentally investigated by comparing the catalytic performance of WO₃ in different morphologies. Nanoparticles (W-NP), nanorods (W-NR) and microspheres self-assembled by nanorods (W-MP) of WO₃ were synthesized by using different carboxylic acid structure-directing agents. Based on this, the impregnation method was adopted to form the composite catalysts including the Ce/W-NP, the Ce/W-NR and the Ce/W-MP. After the impregnation of Ce species_, a new redox cycle of Ce⁴⁺+W⁵⁺↔Ce³⁺+W⁶⁺ is formed due to the interaction of W and Ce ions, which significantly facilitates the redox reaction on the composite catalyst. However, compared with nanorods (W-NR) and microspheres self-assembled by nanorods (W-MP), WO₃ nanoparticles (W-NP) enclosed with (0 0 1) facets of the hexagonal WO₃ shows the best redox ability due to the largest molar ratio of W⁵⁺/(W⁵⁺+W⁶⁺) and the highest concentration of Ce⁴⁺ on the surface of Ce/W-NP, which was proven by the results of XPS. As a consequence, the Ce/W-NP presents the strongest surface redox properties and the largest molar ratio of O_α/(O_α+O_β), which is beneficial to promote the NH₃-SCR activity of the catalyst. It is worth mentioning that the morphology of tungsten oxide that remarkably affects the activity of the catalyst is determined by tartaric acid, citric acid and oxalic acid, indicating the significance of the structure-directing agents for improving the NH₃-SCR activity of the impregnated Ce/W catalyst.

通过比较WO ₃在不同形态下的催化性能，实验研究了氧化钨对负载型CeO ₂催化剂的NH ₃ -SCR活性的形态学影响。利用不同的羧酸结构导向剂，合成了由WO ₃的纳米棒（W-MP）自组装的纳米粒子（W-NP），纳米棒（W-NR）和微球。在此基础上，采用浸渍法制备了Ce / W-NP，Ce / W-NR和Ce / W-MP复合催化剂。铈物种的浸渍后_，铈的一种新的氧化还原循环⁴⁺ + W ⁵⁺ ↔Ce ³⁺ + W ⁶⁺由于W和Ce离子的相互作用而形成了H 2 O 3，这大大促进了复合催化剂上的氧化还原反应。但是，与由纳米棒（W-MP）自组装的纳米棒（W-NR）和微球相比，被六方WO _3的（0 0 1）面包围的WO ₃纳米颗粒（W-NP）具有最佳的氧化还原能力XPS的结果证明，W ⁵⁺ /（W ⁵⁺ + W ⁶⁺）的最大摩尔比和Ce / W-NP表面的Ce ⁴⁺浓度最高。其结果是，Ce的/ W-NP呈现最强的表面氧化还原性质和的O-最大摩尔比_α /（O _α + O _β），这有利于促进催化剂的NH ₃ -SCR活性。值得一提的是，明显影响催化剂活性的氧化钨的形态是由酒石酸，柠檬酸和草酸决定的，表明结构导向剂对于提高浸渍后的NH ₃ -SCR活性的重要性。Ce / W催化剂。