Mn-Interconnected NiCo Layered Double Hydroxide Nanosheets on Ni Foam for Electrocatalytic Concurrent Glycerol Conversion to Hydrogen and Formate

Utilizing KMnO4 and glycerol as co-precursors in a previously unexplored manner, we hydrothermally synthesized Mn-interconnected NiCo layered double hydroxide (LDH) ultrathin nanosheets directly grown on nickel foam (denoted as Mn–NiCo@NF-G). KMnO4 was used as a Mn source and a strong oxidant for generating Ni2+, while glycerol provided interlayer CO32– ions and facilitated the formation of ultrathin LDH architectures. Comprehensive characterizations revealed that Mn was selectively incorporated into vacancy clusters of the Ni substrate and linked with Co, Mn, and O atoms via Mn---Co–O bonds, resulting in a robust interfacial coupling between the nanosheets and support. This unique structural configuration substantially enhanced charge transport and exposed a large electrochemically active surface area. The Mn–NiCo@NF-G electrode generated a current density of 10 mA·cm–2 at a low overpotential of 1.30 V vs RHE, and its Tafel slope was small (72 mV·dec–1). Furthermore, the electrocatalyst remained stable for 20 h of continuous operation. Remarkably, the catalyst exhibited over 90% selectivity for oxidizing glycerol to formate, demonstrating its potential for efficient and selective biomass conversion. These findings suggested a Mn–NiCo@NF-G electrode to be an effective bifunctional electrocatalyst for concurrent hydrogen production and synthesizing value-added chemicals.