This study focuses on the effect of gas composition during SO₂ poisoning over Cu/SSZ-13 for NH₃-SCR application and was performed by conducting SO₂-TPD experiments in a variety of lean gas compositions. In addition, the poisoned monoliths were characterized in detail using ICP-SFMS, UV–vis and XPS. During SO₂ poisoning under dry and lean conditions, two different sulfur species were found, which were assigned to weakly bound SO₂ and copper sulfate like species. Moreover, a significantly larger amount of copper sulfates was present in humid environment. The presence of NH₃ during the poisoning resulted in the formation of ammonium sulfate species which were decomposed at the same temperature independently if the poisoning with SO₂ was conducted in ammonia oxidation conditions or under standard or fast SCR conditions. Moreover, if the temperature ramp was conducted with O₂ and H₂O compared to Ar alone, more stable sulfate species were formed. In addition, SO₂ poisoning under standard SCR conditions resulted in mostly ammonium sulfate formation at 200 °C, whereas copper sulfates were predominant after poisoning at 400 °C. After hydrothermal aging at 800 °C, more reducible copper species were noticeable and UV–vis showed that copper oxides had been formed. Sulfur poisoning of the hydrothermally aged sample resulted in the additional formation of copper sulfates during poisoning at 200 °C, which was not the case for poisoning of the fresh catalyst. Thus, the copper oxide species enhanced the copper sulfate formation.

这项研究的重点是针对SO _3中的气体成分对Cu / SSZ-13的NH ₃ -SCR的影响，并通过在各种稀薄气体成分中进行SO ₂ -TPD实验来进行。此外，使用ICP-SFMS，UV-vis和XPS对中毒的整料进行了详细表征。在干燥和稀薄条件下的SO ₂中毒过程中，发现了两种不同的硫物质，它们分别属于弱结合的SO ₂和类似硫酸铜的物质。此外，在潮湿的环境中存在大量的硫酸铜。NH ₃的存在如果在氨氧化条件下或在标准或快速SCR条件下用SO ₂进行中毒，则中毒过程中会形成硫酸铵物种，这些硫酸铵物种会在相同温度下独立分解。此外，如果与单独使用Ar相比，使用O ₂和H ₂ O进行温度上升，则会形成更稳定的硫酸盐。此外，SO ₂在标准SCR条件下中毒会导致在200°C时形成大量硫酸铵，而在400°C中毒后硫酸铜则占主导地位。在800°C的水热老化后，可还原的铜种类更加明显，而UV-vis显示已经形成了氧化铜。水热老化样品的硫中毒导致在200°C的中毒过程中另外形成了硫酸铜，而新鲜催化剂中毒的情况并非如此。因此，氧化铜物质增强了硫酸铜的形成。