In-situ interzeolite transformation synthesis Cu-SSZ-13 from coal fly ash-derived zeolite for NH3-SCR reaction.

Cu-SSZ-13 catalyst has excellent performance for removing NO x. In this study, the in-situ inter-zeolite transformation (IZT) method was proposed to prepare Cu-SSZ-13 catalyst. The coal fly ash-derived zeolite acted as a raw material rather than the chemical silicon and aluminum source. A series of catalysts were prepared using the in-situ IZT method with different ratios of the two template agents. The NO conversion of Cu-SSZ-13 catalysts was above 90 % within the temperature range of 200–700 °C, whereas the N 2 selectivity was maintained at about 100 %. The as-synthesized catalysts had higher conversion rates for Si and Al, higher copper loading and more isolated Cu²⁺. The selective catalytic reduction (SCR) reaction mechanisms of Cu-SSZ-13 catalyst prepared using the in-situ IZT method followed both the Eley-Rideal (E-R) mechanism and the Langmuir-Hinshelwood (L-H) mechanism, though it was mainly based on the E-R reaction. In this study, the Cu-SSZ-13 catalysts were synthesized using coal fly ash based zeolite in one step. This study further improved the synthesis process route from coal based solid waste to SCR catalyst, shortened the preparation cycle, and improved catalyst performance. [Display omitted] • Propossing a new synthesis method of high Si/Al ratio molecular sieve catalysts. • Synthesized Cu-SSZ-13 catalyst by one step using coal fly ash-derived zeolite. • Adjust the Si/Al ratio and Cu location by changing the ratio of the two templates. • High NO conversion and N 2 selectivity in the wide temperature range of 200–700 °C. [ABSTRACT FROM AUTHOR]