Enhancing performance of Fe-SSZ-13 and Cu-Fe-SSZ-13 zeolites for selective catalytic reduction reaction via post-treatment method

Fe-SSZ-13 zeolites were prepared via post-treatment method by using different concentrations of HNO3 solution. Prior to HNO3 treatment, Fe-SSZ-13 was synthesized by using Fe(III)-ethylenediaminetetraacetic acid as iron source. The evaluation of ammonia-assisted selective catalytic reduction reaction indicates that Fe-SSZ-13 and Cu-Fe-SSZ-13 after HNO3 treatment show enhanced catalytic performance compared with corresponding initial counterparts, respectively. Particularly, after hydrothermal ageing (HTA), Cu-Fe-SSZ-13-0.4-HTA with optimal HNO3 concentration of 0.4 M exhibits ∼5% higher NO conversion than Cu-Fe-SSZ-13-0-HTA at 150–250 °C and 450–550 °C. The superior NH3-SCR performance of HNO3-treated zeolites is attributed to that HNO3-treatment method can regulate the distribution of Fe species by decreasing FexOy and increasing isolated Fe3+ content.