Document Type

Article

Publication Date

4-1-2019

Abstract

The highly efficient electrochemical hydrogen evolution reaction (HER) provides a promising way to solve energy and environment problems. In this work, various transition metals (Fe, Co, Ni, Cu, Ag, and Pt) were selected to support on molybdenum carbides by a simple organic-inorganic precursor carburization process. X-ray diffraction (XRD) analysis results indicated that the ß-MO₂C phase was formed in all metal-doped samples. X-ray photo­electron spectroscopy analysis indicated that the binding energy of MO₂+ species (MO₂C) shifted to a lower value after metal was doped on the molybdenum carbide surface. Comparing with pure ß-MO₂C, the elec­trocatalytic activity for HER was improved by transition metal doping on the surface. Remarkably, the catalytic activity improvement was more obvious when Pt was doped on molybdenum carbide (2% Pt-MO₂C). The 2% Pt-MO₂C required a ?_10 of 79 mV, and outperformed that of pure ß-MO₂C (?10 = 410 mV) and other transition metal doped molybdenum carbides, with a small Tafel slope (55 mV/dec) and a low onset overpo­tential (32 mV) in 0.5 M H₂SO₄. Also, the 2% Pt-MO₂C catalyst demonstrated a high stability for the HER in 0.5 M H₂SO₄. This work highlights a feasible strategy to explore efficient electrocatalysts with low cost via engineering on the composition and nanostructure.

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