To shed light on the relationships among catalyst calcination temperature, physicochemical properties and catalytic properties of Fe-SSZ-13, a series of catalysts prepared by aqueous post-synthetic exchange and calcined at different temperatures are characterized and evaluated in NH₃-SCR reaction. The characterizations and kinetic analysis indicate that the calcination temperature has a great effect on the acidity, Fe species distribution and catalytic properties of the Fe-SSZ-13 catalyst. The rise of calcination temperature decreases the low-temperature activity (< 425℃) and conversely improves the high-temperature activity of Fe-SSZ-13. It could be attributed to the following reasons: under low calcination temperatures, more isolated Fe³⁺ ions are maintained which can behave as Lewis acid sites and active sites in low reaction temperatures. Simultaneously, stronger surface acidity helps to alleviate NH₃ inhibition effect at low temperatures, resulting in good low-temperature activity. On the other hand, the high calcination temperature brings about slight aggregation of isolated Fe³⁺ to form dimeric/oligomeric Fe clusters, leading more superior high-temperature activity. On the whole, the major active Fe species as well as the contribution of acid sites for low/high temperature activity are different. It could be concluded that the isolated Fe³⁺ ions and oligomeric Fe clusters are the active sites for low/high SCR reaction temperature, respectively. And zeolite acidity plays a more important role in low-temperature SCR reaction catalyzed by Fe-SSZ-13.

为了阐明催化剂煅烧温度、物理化学性质和Fe-SSZ-13催化性能之间的关系，对一系列通过水合成后交换制备并在不同温度下煅烧的催化剂在NH ₃ -SCR反应中进行了表征和评价。表征和动力学分析表明，煅烧温度对Fe-SSZ-13催化剂的酸度、Fe物种分布和催化性能有很大影响。煅烧温度的升高降低了Fe-SSZ-13的低温活性（<425℃），反之提高了Fe-SSZ-13的高温活性。可归因于以下原因：在较低的煅烧温度下，更多的Fe ³⁺在低反应温度下可作为路易斯酸位点和活性位点的离子得以保留。同时，较强的表面酸性有助于缓解低温下的NH ₃抑制作用，从而产生良好的低温活性。另一方面，较高的煅烧温度导致孤立的Fe ³⁺轻微聚集形成二聚/低聚Fe簇，从而导致更优异的高温活性。总体而言，主要的活性铁物种以及酸位对低温/高温活性的贡献是不同的。可以得出结论，分离的 Fe ³⁺离子和低聚铁簇分别是低/高 SCR 反应温度的活性位点。而沸石酸度在Fe-SSZ-13催化的低温SCR反应中起更重要的作用。