Synergistic Dual-Metal Active Sites in Metallophthalocyanine-Based 2D Conductive Metal-Organic Frameworks for...

Electrochemical glycerol oxidation reaction (GOR) represents a compelling strategy to simultaneously valorize biomass-derived waste and reduce the energy demand of hydrogen production. Herein, we report a systematic investigation of metal identity and spatial arrangement in a series of isoreticular metallophthalocyanine-based two-dimensional conductive metal-organic frameworks (2D cMOFs)-NiPc-O-Ni, CuPc-O-Ni, and CuPc-O-Cu-as bifunctional electrocatalysts for glycerol oxidation and hydrogen evolution. By isolating the roles of the phthalocyanine-centered metal and the bridging metal node within an M1Pc-O-M2 architecture, clear structure-activity relationships are established. Among the three analogs, NiPc-O-Ni exhibits the highest GOR activity and selectivity, achieving 10 mA cm-2 at an anodic potential of only 1.33 V (vs RHE) with a Faradaic efficiency of up to 71% for formate formation in alkaline media. In situ spectroscopic analyses reveal stable framework integrity under operating conditions and provide spectroscopic evidence for formate-related surface intermediates. Owing to its excellent bifunctional performance, NiPc-O-Ni enables efficient glycerol-assisted electrolysis when employed as both anode and cathode, delivering a cell voltage of 1.99 V at 10 mA cm-2-230 mV lower than conventional water splitting-while maintaining near-quantitative hydrogen evolution Faradaic efficiency. This work demonstrates the promise of rationally designed 2D cMOFs for coupling biomass oxidation with hydrogen production and offers fundamental insights into the role of metal site identity and cooperativity in complex electrocatalytic reactions.