A Type of 1 nm Molybdenum Carbide Confined within Carbon Nanomesh as Highly Efficient Bifunctional Electrocatalyst

Highly efficient platinum-alternative bifunctional catalysts by using abundant non-noble metal species are of critical importance to the future sustainable energy reserves. Unfortunately, current electrocatalysts toward hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) are far from satisfactory because of lacking reasonable design and assembly protocols. A type of 1-nm molybdenum carbide nanoparticles confined in mesh-like nitrogen-doped carbon (Mo₂C@NC nanomesh) with high specific surface area is reported here. In addition to the superior ORR performance comparable to platinum, the catalyst offers a high HER activity with small Tafel slope of 33.7 mV dec⁻¹ and low overpotential of 36 mV to reach −10 mA cm⁻². Theoretical calculations indicate that the active sites of the catalyst are mainly located at Mo atoms adjacent to the N-doped carbon layer, which contributes the high HER activity. These findings show the great potential of Mo₂C species in wide electrocatalysis applications.