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Ultrafine Molybdenum Carbide Nanoparticles Composited with Carbon as a Highly Active Hydrogen‐Evolution Electrocatalyst
Author(s) -
Ma Ruguang,
Zhou Yao,
Chen Yongfang,
Li Pengxi,
Liu Qian,
Wang Jiacheng
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201506727
Subject(s) - tafel equation , electrocatalyst , catalysis , ammonium molybdate , molybdenum , materials science , graphene , nanoparticle , exchange current density , chemical engineering , platinum , carbon fibers , carbide , inorganic chemistry , chemistry , nanotechnology , electrochemistry , composite number , metallurgy , electrode , organic chemistry , composite material , engineering , zinc
The replacement of platinum with non‐precious‐metal electrocatalysts with high efficiency and superior stability for the hydrogen‐evolution reaction (HER) remains a great challenge. Herein, we report the one‐step synthesis of uniform, ultrafine molybdenum carbide (Mo 2 C) nanoparticles (NPs) within a carbon matrix from inexpensive starting materials (dicyanamide and ammonium molybdate). The optimized catalyst consisting of Mo 2 C NPs with sizes lower than 3 nm encapsulated by ultrathin graphene shells (ca. 1–3 layers) showed superior HER activity in acidic media, with a very low onset potential of −6 mV, a small Tafel slope of 41 mV dec −1 , and a large exchange current density of 0.179 mA cm −2 , as well as good stability during operation for 12 h. These excellent properties are similar to those of state‐of‐the‐art 20 % Pt/C and make the catalyst one of the most active acid‐stable electrocatalysts ever reported for HER.