Optimized ultrafast flow synthesis of CON-type zeolite and improvement of its catalytic properties

Abstract

The synthesis time for CON-type aluminoborosilicate zeolite ([Al, B]-CON), a promising catalyst for methanol-to-olefin reactions, was reduced from 20 h to 45 min, the fastest reported so far for this zeolite. In addition to overcoming thermal lag by the use of tubular reactors at high temperatures, optimizing the reactant composition, choosing proper seed crystals, their quantity, size, and timing of addition were also instrumental in the fast-paced synthesis of [Al, B]-CON. It was found that obtaining a pure CON phase at a faster rate depends not only on the synthesis temperature, but also on the ageing temperature, amount of seed, and their partial dissolution. The fast synthesis of [Al, B]-CON could be an option for mass production using a demonstrated continuous flow synthesis system. The catalytic activity and stability of the fast-synthesized [Al, B]-CON was improved by the introduction of mesopores via alkaline treatment with amphiphilic molecules.