Abstract Herein, the influence of ammonia titration on the NH3-SCR activity of the tungsten-doped CeO2 catalyst synthesized via the starch bio-template spread self-combustion (SSC) method was investigated. The titration of ammonia water restrains the growth up of cubic CeO2 crystallite and the formation of Ce4W9O33 in Ce4W2Oz(w/o) when the titration pH value of solution is up to 7.0, thus enhances the dispersion of cerium species and the concentration of tungsten on the surface of catalyst. Meanwhile, the further titration of ammonia water promotes the growth up of cubic CeO2 in Ce4W2Oz(pH ≈ 7), decreases its BET surface area and increases its surface concentration of cerium species. And Ce4W2Oz(pH ≈ 9) presents less surface acid sites than Ce4W2Oz(pH ≈ 7) and Ce4W2Oz(w/o), although its surface concentration of tungsten species is higher than that of Ce4W2Oz(w/o). Ce4W2Oz(pH ≈ 7) exhibits the best NH3-SCR activity with more than 86% NOx conversion obtained at the temperature range of 275–500 °C. In addition, the formation of the smaller particle size cubic CeO2 crystallite plays an important role on the catalytic performance of the tungsten-doped CeO2 catalyst synthesized via the starch bio-template SSC method.

中文翻译：

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用 NH3 选择性催化还原 NO 的 W 掺杂 CeO2 的淀粉生物模板合成：氨滴定的影响

摘要 本文研究了氨滴定对淀粉生物模板扩散自燃法合成的掺钨 CeO2 催化剂 NH3-SCR 活性的影响。当溶液的滴定pH值达到7.0时，氨水滴定抑制了立方CeO2微晶的生长和Ce4W2Oz(w/o)中Ce4W9O33的形成，从而增强了铈物种的分散和钨的浓度。催化剂表面。同时，氨水的进一步滴定促进了Ce4W2Oz(pH ≈ 7)中立方CeO2的生长，降低了其BET表面积并增加了铈物种的表面浓度。Ce4W2Oz(pH ≈ 9) 的表面酸性位点比 Ce4W2Oz(pH ≈ 7) 和 Ce4W2Oz(w/o) 少，尽管其表面钨物质浓度高于 Ce4W2Oz(w/o)。Ce4W2Oz(pH ≈ 7) 表现出最佳的 NH3-SCR 活性，在 275–500 °C 的温度范围内获得超过 86% 的 NOx 转化率。此外，较小粒径的立方CeO2微晶的形成对通过淀粉生物模板SSC法合成的钨掺杂CeO2催化剂的催化性能起着重要作用。