Oxidative coupling of carbon monoxide to dimethyl oxalate: catalysts design, reaction mechanism and process intensification

Significant efforts have been directed toward the advancement of active and durable Pd−based catalysts for the gas−solid phase oxidative coupling of carbon monoxide (CO) to dimethyl oxalate (DMO). The reaction takes place under moderate conditions with high selectivity above > 95% following the C1 chemistry route and converting C1 feedstocks, i.e. CO and methanol (CH3OH) to DMO product. The inaugural plant capable of processing 200,000 tons annually, was commissioned in 2009, and as of 2023 more than 30 such plants are in operation. Noteworthy attention has been dedicated to enhancing catalytic activity while minimizing the Pd active component, achieved through the construction of efficient nanostructured catalysts. In this review, we highlight the recent advances in the CO oxidative coupling to DMO, particularly focusing on the design of Pd−based catalysts, structure−function relationship, catalytic reaction mechanism and process intensification utilizing structured catalysts. Additionally, an overview addressing challenges and opportunities for future research associated with CO oxidative coupling to DMO is presented.