A multi-site kinetic model was developed to predict the effect of sulfur dioxide on Cu-SSZ-13 for the NH₃ selective catalytic reduction (NH₃-SCR) of NO_x. To develop a mechanism-based kinetic model, two different Cu sites were assumed describing the formation–decomposition of S intermediates i.e. copper bisulfite on ZCuOH (site 1, S1) and ammonium sulfate on Z₂Cu (site 2, S2). Transient kinetics of SO₂ interactions with Cu-SSZ-13 were simulated, exploiting SO₂ and SO₂ + NH₃ temperature programmed desorption (TPD) experiments. Besides S1 and S2, a 3rd site was assumed to account for the Brønsted acid site and NH₃ adsorption on that site. The model also accounts for NH₃-SCR activity over fresh, sulfated and regenerated (at 550 °C) Cu-SSZ-13 samples with different Si : Al and Cu : Al ratios. Finally, the model was capable of describing fresh SCR for commercial and prepared samples without tuning any kinetic parameters, but by only varying ZCuOH and ZCu site densities obtained utilizing H₂ temperature programmed reduction (H₂-TPR) and inductively coupled plasma optical emission spectroscopy (ICP-OES).

中文翻译：

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用于NH ₃ -SCR应用的Cu-SSZ-13硫化和脱硫的基于机理的动力学建模†

多站点动力学模型的开发是为了预测为NH二氧化硫对Cu-SSZ-13的效果₃选择性催化还原（NH ₃ -SCR）NO的_X。为了建立基于机理的动力学模型，假设使用两个不同的Cu位点来描述S中间体的形成和分解，即ZCuOH上的亚硫酸氢铜（位点1，S1）和Z ₂ Cu上的硫酸铵（位点2，S2）。利用SO ₂和SO ₂ + NH ₃模拟了SO ₂与Cu-SSZ-13相互作用的瞬态动力学。程序升温脱附（TPD）实验。除S1和S2外，还假设第三个位点是Brønsted酸位点和该位置上NH ₃吸附的原因。该模型还说明了在具有不同Si：Al和Cu：Al比例的新鲜，硫酸化和再生（在550°C）Cu-SSZ-13样品上NH ₃ -SCR的活性。最后，该模型能够描述商业和制备样品的新鲜SCR，而无需调整任何动力学参数，而仅改变通过使用H ₂程序升温还原（H ₂ -TPR）和电感耦合等离子体发射光谱法获得的ZCuOH和ZCu位置密度（ICP-OES）。