Low-temperature operation of urea/NH₃-SCR converters, required by recent emission regulations, is challenging due to technological limits related to poor catalytic activity, difficult urea decomposition and undesired ammonium nitrate formation. Herein, we present a novel concept of a catalytic device, which adds a NO_x storage functionality to a typical SCR catalyst. This enables capture and storage of NO_x in lean exhaust streams already at room temperature, with significant efficiencies under dry conditions, as well as direct reduction of the stored NO_x at higher temperatures. The proposed system (AdSCR = adsorption + selective catalytic reduction) is intrinsically different from the well-known existing NO_x storage reduction (LNT) + SCR systems. In fact, it is free of PGM materials and does not require lean–rich cycling, being operated just like an SCR catalyst. It has therefore potential advantages both in terms of costs and flexibility of the aftertreatment configuration: in principle, it can be integrated into conventional SCR converters, leading to improved deNO_x efficiencies without additional modifications of the aftertreatment architecture.

中文翻译：

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不含PGM的NO _x吸附剂+选择性催化还原催化剂系统（AdSCR），用于在低温下捕集和还原稀薄排气流中的NO _x †

由于与不良的催化活性，难于的尿素分解和不希望的硝酸铵形成有关的技术限制，最近的排放法规要求尿素/ NH ₃ -SCR转化器的低温操作是具有挑战性的。在此，我们提出了一个催化装置，其增加了NO的一种新颖的概念_X存储功能，以典型的SCR催化剂。这使得能够在室温下已经在稀薄的排气流中捕获和存储NO _x，并且在干燥条件下具有显着的效率，并且能够在较高温度下直接还原所存储的NO _x。所提出的系统（ADSCR =吸附+选择性催化还原）是从公知的现有NO本质不同_X减少存储（LNT）+ SCR系统。实际上，它不含PGM材料，不需要像SCR催化剂一样操作的贫富循环。它既有在成本和后处理配置的灵活性方面因此潜在的优点：在原理上，可以被集成到现有的SCR转换器，从而导致改善DENO _X效率而不后处理体系结构的附加的修改。