Hyounmyung Park, Yuemei Zhang, Eunsoo Lee
Jul 10, 2019
Citations
0
Influential Citations
35
Citations
Journal
ChemSusChem
Abstract
Transition metal borides belong to a small class of non-noble-metal electrocatalysts which exhibit excellent activity toward hydrogen evolution reaction (HER) already in bulk form, especially those containing the graphene-like (flat) boron layers such as α-MoB2 are particularly promising. In this study, we report on the first tungsten-based boride HER electrocatalysts studied experimentally and theoretically. We show that tungsten, whose diborides (α- and β-WB2) contain both the active graphene-like (flat) boron layer and the less active phosphorene-like (puckered) boron layer, can be successfully substituted (up to 30 at.%) for molybdenum in α-MoB2. The resulting α-Mo1-xWxB2 exhibits better HER activity and stability than the binaries WB2 and MoB2, especially at high current density in acidic electrolytes. DFT calculations show that the graphene-like boron layer is the most active among the studied surfaces and that tungsten promotes hydrogen generation by facilitating bonding between hydrogen atoms in contrast to molybdenum. These results should pave the way for high current density, abundant and inexpensive bulk and nanoscale HER catalysts by applying structure-activity relationships.