β Zeolite/bentonite composite as a novel catalyst for condensation of aniline to diphenylamine

β Zeolite/bentonite composite was synthesized by simple kneading as catalyst for condensation reaction of aniline to diphenylamine. The experiment which was conducted at 320 °C under 2 MPa with a liquid hourly space velocity (LHSV) of 2 h−1 showed that the Hβ zeolite loading 25% clay exhibited the highest activity (9.9% aniline conversion) and selectivity. Pilot experiments (315–320 °C, 2 MPa, LHSV of 0.20–0.22 h−1) have also confirmed that the catalyst had good stability. The crystalline structure, acidic property and textural property of the catalysts were characterized by XRD, Py-IR, N2 adsorption–desorption. Moreover, according to the thermodynamic analysis, the condensation of aniline to diphenylamine is an exothermic reaction, indicating that too high temperature operation is unfavorable for the reaction. The studied β zeolite/bentonite composite is of promising efficiency in condensation of aniline to diphenylamine.