Synthesis and Characterization of Magnesium-Manganese Based Oxide on Nickel Foam for Electrochemical CO₂ Reduction to Formate

Abstract

The increasing levels of atmospheric CO₂ from industrial activities necessitate effective technologies to mitigate climate change. Electrochemical CO₂ reduction offers a promising route to convert CO₂ into valuable products like formate, but challenges such as high overpotential, low selectivity, and catalyst instability hinder its efficiency. Conventional catalysts, while effective, often suffer from low performance or high costs, driving the search for alternative materials. This research explores magnesium-manganese oxide-based catalysts on nickel foam, leveraging their synergistic effects, unique structural properties, and cost-effectiveness to enhance Electrochemical CO2 reduction efficiency. The catalysts were directly grown on nickel foam via immersion in a precursor solution followed by calcination at 600°C. Structural and compositional analysis through X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) confirmed the formation of crystalline phases, including Ni₆MnO₈, NiO, and NiMnO₃, with magnesium likely incorporated into the manganese oxide lattice. SEM revealed coral reef-like morphology, while elemental analysis indicated a uniform distribution of magnesium (1.1%) and manganese (22.1%) within the porous nickel foam. The optimized catalyst, Mg1.1-Mn22.1-Ox/NiF, exhibited superior electrocatalytic performance, achieving a high current density of -63.24 mA cm⁻² at -0.85 V vs. RHE and a low onset potential of 0.07 V, indicating improved charge transfer capabilities. These findings highlight the structural and compositional advantages of magnesium integration, significantly enhancing catalytic activity and stability. This work provides valuable insights into the design of advanced electrocatalysts for efficient CO₂ reduction, paving the way for further optimization and exploration of magnesium-manganese-based oxides systems.