Preparation of CuHY catalyst via solid-state ion exchange method and its catalytic performance in isobutane/2-butene alkylation

Abstract

CuHY samples prepared by solid-state ion exchange of HY zeolite with CuCl were used as catalysts in isobutane/2-butene alkylation. The results show that both the addition amount of CuCl and the calcination temperature affect the ion exchange degree. Cu⁺ can be introduced into Y zeolite by replacing H⁺ in the HY zeolite after the solid-state ion exchange, causing a decrease of the amount of Brønsted acid sites and an increase of that of Lewis acid sites. When taking CuHY as the catalyst in isobutane/2-butene alkylation, the 3d¹⁰4s⁰ valence electron configuration of Cu⁺ makes it favorable for inhibiting the oligomerization of 2-butene and accelerating the hydride transfer reaction rate by indirectly increasing the local isobutane/olefin ratio around the acid sites of the catalyst. As a result, the selectivity of C8 and trimethylpentanes over CuHY in alkylate are improved compared with those of HY.