NH4F modified β zeolite for aniline condensation to diphenylamine and its catalytic mechanism

Abstract

The main factors affecting the performance of solid acid catalyzed liquid-phase condensation of aniline to diphenylamine are acidity and pore structure. Fluorine has strong electron affinity due to its special electronic structure, which can adjust the acidity and pore structure of zeolite. β zeolite was modified with different concentrations of NH4F solution. The aluminum in the framework of aluminosilicate zeolite was removed to a certain extent, and the acidity and pore size of β zeolite were controlled. Combined with XRD, Py-IR, Al MAS NMR and DRIFTS the active center and reaction mechanism of the catalytic reaction were discussed.