Electrochemical performance of α-Mo2C as catalyst for the hydrogen evolution reaction

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Switzerland), 2017-05, Vol.793, p.235-241
• Main Authors: García, G., Roca-Ayats, M., Guillén-Villafuerte, O., Rodríguez, J.L., Arévalo, M.C., Pastor, E.
• Format: Article
• Language: English
• Subjects: DEMS; Electrochemical stability; Hydrogen evolution reaction; Molybdenum carbide
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2017.01.038

Hexagonal molybdenum carbide (α-Mo2C) was evaluated as platinum-free catalyst for the hydrogen evolution reaction (HER) in sulphuric acid medium. With this end in view, α-Mo2C was synthesized following a simple carbothermal route that conceives large amount of the transition metal carbide with nanometric size and pure crystalline phase. The synthesized nanoparticles were characterized by XRD, EDX and XPS, and the performance of α-Mo2C catalyst during the HER was investigated using a rotating disk electrode (RDE). In addition, differential electrochemical mass spectrometry (DEMS) was employed for an accurate determination of the onset potential of the reaction (−0.075V vs RHE) and to study the degradation process of the catalyst. Main results indicate high catalytic activity of the active phase (α-Mo2C) toward the HER and suitable stability, although both properties were strongly affected after a strong oxidative degradation test. These three parameters (onset potential, activity and stability) can be improved by decreasing the degree of surface oxide species, which is currently under investigation. [Display omitted] •Nanometric α-Mo2C particles were synthesized by a simple carbothermal route.•α-Mo2C was employed as platinum-free catalyst for the hydrogen evolution reaction (HER).•The catalytic performance toward the HER was studied by differential electrochemical mass spectrometry (DEMS).•Very low onset potential of −0.075V for the HER was accurately determined by DEMS.•α-Mo2C catalyst revealed elevated catalytic activity toward the HER in acidic medium.