A Janus conductive MOF-on-conductive-MOF heterostructure enables simultaneous production of H2O2 and active chlorine by seawater electrolysis

Seawater electrolysis is an ideal strategy for the simultaneous production of H2O2 and active chlorine, but it has yet to be realized. In this study, a rationally designed conductive metal–organic framework (cMOF)-on-cMOF electrocatalyst is presented for seawater electrolysis. The negatively charged Co-cMOF and positively charged Cu-cMOF units respectively facilitate Cl− repulsion at the cathode and Cl− enrichment at the anode. Moreover, the formation of interfacial Cu–O–Co bonds generates anisotropic active sites with tailored electronic structures for H2O2 and chlorine generation. Additionally, the cMOF-on-cMOF design provides a built-in electric field and enhanced charge transfer. Consequently, the Janus electrocatalyst delivers high production rates and Faradaic efficiencies for both H2O2 (9.34 mol gcat−1 h−1 and 95.1%) and chlorine (9.26 mol gcat−1 h−1 and 94.3%), with a long-term stability of over 100 h in an integrated seawater electrolyzer. This work provides insights into the design of both advanced materials and electrocatalytic systems for the production of value-added chemicals in seawater.