Energy-conservative CO2 electroreduction for efficient formate co-generation

Developing energy-conservative and highly efficient electrochemical systems is an appealing approach to co-generating value-added chemicals while simultaneously reducing energy input. In this work, an integrated electrochemical system combining CO 2 electroreduction (CO 2 RR) and polyethylene terephthalate (PET) plastic upcycling is developed for the efficient co-generation of formate. The cathodic electrocatalyst, comprising BiOI nanoclusters confined within carbon nanospheres, demonstrates excellent selectivity and stability for formate formation. The strong electronic metal-support interaction between BiOI nanoclusters and carbon substrate not only enhances CO 2 adsorption and charge transfer capabilities but also effectively modulates the electronic structure to facilitate CO 2 RR. Coupled with a highly active anodic electrocatalyst, NiCo 2 O 4 nanosheets grown on Ni foam, this integrated system achieves a formate Faradaic efficiency (FE) of 90 % at the cathode and 85 % at the anode at 250 mA cm⁻² over 140 hours. Techno-economic analysis further underscores the system’s economic feasibility and underscores its significant potential for commercial applications. • High performance in formate formation is achieved at both the cathode and the anode. • Strong electronic metal-support interaction (ESMI) enhances electrocatalyst durability. • Polyethylene terephthalate (PET) plastic upcycling significantly increases anodic product value. • An energy-efficient electrochemical system demonstrating economic feasibility has been developed.