With regard to the catalysts for NH selective catalytic reduction (NH-SCR), the acid sites distribution can affect the adsorption of reactants and formation of intermediates, thus determining the reaction routines. In this work, a representative acidic component, monoclinic-WO (m-WO), was used to probe the combination strategy of experimental and theoretical research, aiming at systematic understanding on the full-process mechanisms. Macro-scale characterizations, Temperature Programmed Desorption (TPD) and Temperature Programmed Reduction (TPR), are associated with the Density Functional Theory (DFT) calculations, by which W ion (Lewis acid site) is affirmed as the active sites. By comparing the energy barriers of possible pathways with DFT calculations, we identify that NHNO and NHNOH are responsible active intermediates. Both Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) pathways may take place on acid sites and the former on Lewis acid site is optimal, which agrees well the in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) analysis. This study offers a reasonable prototype for precisely examining the correlation between the catalyst and mechanisms of NH-SCR catalysts.

中文翻译：

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揭示酸性位点在确定 WO3 催化剂上的 NH3-SCR 机制中的重要性：实验和计算相结合的研究


对于NH选择性催化还原（NH-SCR）催化剂，酸位分布可以影响反应物的吸附和中间体的形成，从而决定反应程序。本工作利用代表性酸性组分单斜WO（m-WO）探索实验与理论研究的结合策略，旨在系统地了解全过程机制。宏观尺度表征、程序升温脱附（TPD）和程序升温还原（TPR）与密度泛函理论（DFT）计算相关，通过该计算，W离子（路易斯酸位点）被确认为活性位点。通过将可能路径的能垒与 DFT 计算进行比较，我们确定 NHNO 和 NHNOH 是负责任的活性中间体。 Langmuir-Hinshelwood (L-H) 和 Eley-Rideal (E-R) 途径都可能发生在酸性位点上，前者在 Lewis 酸性位点上是最佳的，这与原位漫反射红外傅里叶变换光谱 (in situ DRIFTS) 分析非常吻合。这项研究为精确检验催化剂与NH-SCR催化剂机理之间的相关性提供了合理的原型。