Highly Selective Carbonylation of CH₃Cl to Acetic Acid Catalyzed by Pyridine‐Treated MOR Zeolite

Abstract

The selective conversion of methane to high value-added chemicals under mild conditions is of great significance for the commercially viable and sustainable utilization of methane but remains a formidable challenge. Herein, we report a strategy for efficiently converting methane to acetic acid via CH 3 Cl as an intermediate. Up to 99.3 % acetic acid and methyl acetate (AA + MA) selectivity was achieved over pyridine-pretreated MOR (MOR-8) under moderate conditions of 523 K and 2.0 MPa. Water, conventionally detrimental to carbonylation reaction over zeolite catalysts, was conducive to the production of AA in the current reaction system. In the 100 h continuous test with the MOR-8 catalyst, the average AA + MA selectivity remained over 98 %. AA was formed by carbonylation of methoxy groups within 8-membered rings of MOR followed by hydrolysis. This strategy provided an approach for highly efficient utilization of methane to oxygenates under mild reaction conditions.

Cyclic Oxygenate-Based Deactivation Mechanism in Dimethyl Ether Carbonylation Reaction over a Pyridine-Modified H-MOR Catalyst

“…Moreover, these oxygenates are also detected in the spent catalyst when co-feeding CH 3 Cl and CO at 463 K and 2 MPa. It is known that Ac 2 O and the carbonylation of CH 3 Cl can produce acetyl groups on the zeolite catalyst. Thus, it is convincing that cyclic oxygenates can be produced by the acetyl groups.…”