Monodispersed Cu-TCPP/Cu₂O Hybrid Microspheres: A Superior Cascade Electrocatalyst toward CO₂ Reduction to C₂ Products

The electrochemical conversion of carbon dioxide (CO₂) into valuable chemicals is a feasible way to mitigate the negative impacts of overmuch CO₂ emissions. Porphyrin-based metal organic frameworks (MOFs) are expected to be used for selective and efficient electrochemical CO₂ reduction (ECR) with porous structure and ordered active sites. Herein, we report the synthesis of a monodispersed and spherical organic/inorganic hybrid Cu-TCPP@Cu₂O electrocatalyst composed of Cu-TCPP (TCPP = tetrakis (4-carboxyphenyl) porphyrin) and Cu₂O, where TCPP plays significant roles in regulating the morphology. In-situ formed Cu during ECR process in combination with Cu-TCPP (Cu-TCPP@Cu) can suppress hydrogen evolution, enrich CO intermediate and promote C–C coupling toward C₂ products. The Cu-TCPP@Cu supported on porous carbon (PC) showed ultrafine Cu nanoclusters on PC, and displayed high ECR activity and selectivity toward C₂ products, with a C₂ faradaic efficiency of 62.3% at –1.0 V versus the reversible hydrogen electrode and a C₂ partial current density of 83.4 mA·cm^–2, which is 7.6 times and 13.1 times those of pure Cu₂O and TCPP, respectively. The morphology and hybrid structure of the catalyst were studied to improve the selectivity of ECR to produce C₂ products, which provides a new idea for the design of high-performance ECR catalyst.