title: Boron-Dependency of Molybdenum Boride Electrocatalysts for the Hydrogen Evolution Reaction.
abstract: Molybdenum-based materials have been considered as alternative catalysts to noble metals, such as platinum, for the hydrogen evolution reaction (HER). We have synthesized four binary bulk molybdenum borides Mo2B, α-MoB, β-MoB, and MoB2by arc-melting. All four phases were tested for their electrocatalytic activity (linear sweep voltammetry) and stability (cyclic voltammetry) with respect to the HER in acidic conditions. Three of these phases were studied for their HER activity and by X-ray photoelectron spectroscopy (XPS) for the first time; MoB2and β-MoB show excellent activity in the same range as the recently reported α-MoB and β-Mo2C phases, while the molybdenum richest phase Mo2B show significantly lower HER activity, indicating a strong boron-dependency of these borides for the HER. In addition, MoB2and β-MoB show long-term cycle stability in acidic solution.
authors.affiliation: Department of Chemistry, University of California, Riverside, Riverside, CA, 92521, USA.|Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA, 92521, USA.
authors.forename: Hyounmyung
authors.initials: H
authors.lastname: Park
authors.affiliation: Department of Chemistry, University of California, Riverside, Riverside, CA, 92521, USA.|Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA, 92521, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Encinas
authors.affiliation: Department of Chemistry, University of California, Riverside, Riverside, CA, 92521, USA.
authors.forename: Jan P
authors.initials: JP
authors.lastname: Scheifers
authors.affiliation: Department of Chemistry, University of California, Riverside, Riverside, CA, 92521, USA.
authors.forename: Yuemei
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, University of California, Riverside, Riverside, CA, 92521, USA.|Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA, 92521, USA.
authors.forename: Boniface P T
authors.identifier: 0000-0001-9802-7815
authors.initials: BPT
authors.lastname: Fokwa
keywords: X-ray photoelectron spectroscopy; borides; electrolysis; hydrogen evolution reaction; molybdenum