Dual-OSDA Ultrafast Synthesis of AFX Zeolite for Enhanced Catalytic Performance in Selective Catalytic Reduction of NOx with NH3

Abstract

This paper presents a dual- OSDA approach for ultrafast synthesis of AFX zeolite, addressing challenges in terms of cost and synthesis efficiency. By partially replacing the expensive organic structure-directing agent, N,N,N’,N’-tetraethylbicyclo[2.2.2]oct-7-ene-2,3:5,6-dipyrrolidinium, with a more economical alternative, viz., N,N’-bis-triethylpentanediyldiammonium dibromide, this method successfully reduces the synthesis cost while maintaining high crystallinity. Compared with the conventionally synthesized samples, the samples synthesized via the dual-OSDA method exhibited high hydrothermal stability and excellent catalytic performance in the selective catalytic reduction of NOx with NH3 (SCR). Furthermore, employing tubular reactors into the synthesis process facilitated the ultrafast crystallization of AFX zeolite, thus significantly shortening the synthesis time.