The water promotion mechanism in the Fe-BEA catalyst on the NH₃-SCR activity was investigated by in situ DRIFT studies. While a significant amount (mol/g) of Lewis acid sites was formed on the surface of the Fe-BEA without water addition, supplementary hydroxyl species caused Lewis acid sites to be transformed into Brønsted acid sites, thus resulting in more NO₃⁻/NO₂⁻ and NH₄⁺ species adsorbed on the surface which increased the SCR activity under the presence of water.

中文翻译：

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Fe-BEA催化剂上NH ₃ -SCR的水促进机理

通过原位DRIFT研究了Fe-BEA催化剂中水促进NH ₃ -SCR活性的机理。虽然铁-BEA的表面上形成了显著量（微摩尔/克）的路易斯酸位点，而不加入水，补充羟基物质引起路易斯酸位点被转化为布朗斯台德酸位点，从而导致更多的NO ₃ ^- / NO ₂ ^-和NH ₄ ⁺物种吸附其下的水的存在增加了SCR活性的表面上。