Solvent-free synthesis of aluminosilicate SSZ-39 zeolite

Abstract

Aluminosilicate SSZ-39 zeolite shows the excellent catalytic performance in selective catalytic reduction of NO x with NH 3 (NH 3 -SCR) reaction, but their synthesis is still not efficient due to the use of a large amount of water as a solvent under hydrothermal condition. Herein, for the first time, we report a solvent-free synthesis of aluminosilicate SSZ-39 zeolite without addition of water in the presence of N,N-dimethyl-3,5-dimethylpiperidine (DMDMP) cation as an organic structure-directing agent. Various characterizations, including powder X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry-differential thermal analysis (TG-DTA), N 2 sorption, inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis, solid nuclear magnetic resonance (NMR) and NH 3 -temperature-programmed desorption (NH 3 -TPD), show that the aluminosilicate SSZ-39 zeolite displays high crystallinity, uniform sheet-like morphology, large surface area, four-coordinated aluminum species, strong acidic sites and excellent hydrothermal stability. Compared with the conventional synthesis for aluminosilicate SSZ-39 zeolite, the solvent-free synthesis of aluminosilicate SSZ-39 zeolite has the obvious advantages such as high product yield, simple synthesis procedures, and the reduction of pollutants. More importantly, the copper-exchanged aluminosilicate SSZ-39 zeolite shows the good catalytic performance in NH 3 -SCR reaction, which is fully comparable with that of the Cu-SSZ-39 zeolite synthesized under hydrothermal condition from the reported literature. • Aluminosilicate SSZ-39 zeolite is synthesized under solvent-free condition. • This route enhances the utilization efficiency of both the raw materials and space. • The Cu-exchanged SSZ-39 zeolite shows good catalytic performance in NH 3 -SCR reaction. • This route is sustainable.