Bimetallic organic framework derived Co-MoxN/Mo2C catalyst for HER/OER bifunctional electrocatalytic reaction

J Colloid Interface Sci. 2024 Nov 19;680(Pt B):427-436. doi: 10.1016/j.jcis.2024.11.116. Online ahead of print.

Abstract

Metal organic frameworks (MOFs) are widely used as precursors due to their tunable morphology and high specific surface area. Molybdenum nitride (MoN) and molybdenum carbide (Mo2C) are promising catalyst materials with electronic structures similar to the noble metal platinum. However, the preparation and modification of the composite systems comprising MoN and Mo2C are complex, often leading to significant agglomeration and limiting their application in various catalytic fields. In this work, we designed and developed a novel bimetallic Co-MOFs-Mo with a stable and unique framework morphology. By varying the organic ligand content, we controlled the morphology and enhanced the intrinsic electrocatalytic activity through Mo doping. Using the Co-MOFs-Mo sample as the Co source, we fabricated a Co-MoxN/Mo2C catalytic material with a special framework structure. Compared to Mo2N and Mo2N/Mo2C, this catalyst exhibits a larger specific surface area and superior performance in both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The Co-MoxN/Mo2C catalyst achieves an HER overpotential of 297 mV at a current density of 10 mA·cm-2 and an OER overpotential of 480 mV at 20 mA·cm-2. This research provides valuable insights into the rational design of molybdenum-based noble-metal-free catalyst materials.

Keywords: Electrocatalysis; Metal-organic framework materials; Molybdenum-based catalysts; Morphology control.