CO2-H2O co-electrolysis to CO/O2 for safe oxidative double carbonylation of ethylene/acetylene

Upgrading carbon dioxide (CO 2 ) into value-added bulk chemicals offers a dual-benefit strategy for the carbon neutrality and circular carbon economy. Herein, we develop an integrated CO 2 valorization strategy that synergizes CO 2 -H 2 O co-electrolysis (producing CO/O 2 feeds) with oxidative double carbonylation of ethylene/acetylene to synthesize CO 2 -derived C4 diesters (dimethyl succinate, fumarate, and maleate). A group of versatile building blocks for manufacturing plasticizers, biodegradable polymers, and pharmaceutical intermediates. Remarkably, CO 2 exhibits dual functionality: serving simultaneously as a CO/O 2 source and an explosion suppressant during the oxidative carbonylation process. We systematically investigated the explosion-suppressing efficacy of CO 2 in flammable gas mixtures (CO/O 2 , C 2 H 4 /CO/O 2 , and C 2 H 2 /CO/O 2 ) across varying concentrations. Notably, the mixed gas stream from CO 2 /H 2 O co-electrolysis at an industrial-scale current densities of 400 mA/cm 2 , enabling direct utilization in oxidative double carbonylation reactions with exceptional compatibility and inherent safety. Extended applications were demonstrated through substrate scope expansion and gram-scale synthesis. This study establishes not only a safe protocol for oxidative carbonylation processes, but also opens an innovative pathway for sustainable CO 2 valorization, including CO surrogate and explosion suppressant. Safeguarded C4 diesters production: CO 2 -H 2 O co-electrolysis coupled to ethylene/acetylene oxidative double carbonylation.