Abstract

The different forms of Ca (CaCl₂ and Ca(OH)₂) poisoned manganese and cerium oxides supported on TiO₂ catalysts were prepared by impregnation method and used for selective catalytic reduction (SCR) of NO with NH₃. The Ca poisoning effects were investigated by many characterization methods including N₂ adsorption/desorption, X-ray diffraction, X-ray photoelectron spectroscopy, H₂-temperature programmed reduction and NH₃-temperature programmed desorption techniques. The results showed that the addition of Ca led to greatly decrease of catalytic activity of catalysts and the catalytic activity was ranked in the order: CaCl₂ poisoned catalyst < Ca(OH)₂ poisoned catalyst < fresh catalyst, which indicated that the poisoning effect of different forms of Ca was different and the deactivation caused by CaCl₂ was more serious. The characterization results demonstrated the addition of Ca greatly decreased the specific surface area of catalysts, the contents of surface active species (Mn⁴⁺ and Ce³⁺), the amounts of weak Brønsted acid sites and the low-temperature redox ability, especially for the CaCl₂ poisoned catalyst, all of which led to the weaken of the catalytic activity of catalysts.

中文翻译：

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不同Ca前体对TiO 2上负载锰和铈氧化物减少NO活性的影响。

抽象的

通过浸渍法制备了负载在TiO ₂催化剂上的不同形式的Ca（CaCl ₂和Ca（OH）₂）中毒的锰和铈氧化物，并用于NH ₃对NO的选择性催化还原（SCR）。通过许多表征方法，包括N ₂吸附/解吸，X射线衍射，X射线光电子能谱，H ₂程序升温还原和NH ₃程序升温脱附技术，研究了Ca中毒作用。结果表明，Ca的加入导致催化剂的催化活性大大降低，催化活性按以下顺序排列：CaCl ₂中毒催化剂<Ca（OH）₂中毒催化剂<新鲜催化剂，表明不同形式的Ca的中毒效果不同，CaCl ₂引起的失活更为严重。表征结果表明，Ca的添加大大降低了催化剂的比表面积，表面活性物质（Mn ⁴⁺和Ce ³⁺）的含量，弱布朗斯台德酸位的数量以及低温氧化还原能力，特别是对于CaCl ₂中毒的催化剂，所有这些都导致催化剂的催化活性减弱。