One-pot synthesis of FeCu–SSZ-13 using Cu–TEPA as the template by adding iron complexes†
When Cu–TEPA (Cu2+ coordinated with tetraethylenepentamine) is used as a template in the one-pot synthesis of Cu–SSZ-13, Cu2+ will be reduced to Cu0, resulting in a too high Cu content in the product. Herein, by adding iron complexes to the precursor, the reduction of Cu2+ could be inhibited and FeCu–SSZ-13 samples with rational Cu and Fe contents were prepared by a simple one-pot strategy. Although these samples show high activity in the NH3-SCR at low temperature, their high temperature performance is poor due to the lack of strong NH3 adsorption sites such as Brønsted acid sites. Meanwhile, different iron complexes were used as iron sources to synthesize FeCu–SSZ-13, and among them the sample with sodium nitroprusside shows the highest activity. Due to the large ionic radius of K+, it is easily retained which blocks the pores, so the performance of the samples synthesized with a K-type iron source is poorer than that of their Na-type counterparts. Moreover, the activity of the catalyst synthesized with an Fe3+ source is higher than that synthesized with an Fe2+ source because the valence state of Fe sources has a great influence on the Fe chemical state in the catalysts.