  Electrocatalytic hydrogen evolution reaction (HER) in alkaline media is a
promising electrochemical energy conversion strategy. Ruthenium (Ru) is an
efficient catalyst with a desirable cost for HER, however, the sluggish H2O
dissociation process, due to the low H2O adsorption on its surface, currently
hampers the performances of this catalyst in alkaline HER. Herein, we
demonstrate that the H2O adsorption improves significantly by the construction
of Ru-O-Mo sites. We prepared Ru/MoO2 catalysts with Ru-O-Mo sites through a
facile thermal treatment process and assessed the creation of Ru-O-Mo
interfaces by transmission electron microscope (TEM) and extended X-ray
absorption fine structure (EXAFS). By using Fourier-transform infrared
spectroscopy (FTIR) and H2O adsorption tests, we proved Ru-O-Mo sites have
tenfold stronger H2O adsorption ability than that of Ru catalyst. The catalysts
with Ru-O-Mo sites exhibited a state-of-the-art overpotential of 16 mV at 10 mA
cm-2 in 1 M KOH electrolyte, demonstrating a threefold reduction than the
previous bests of Ru (59 mV) and commercial Pt (31 mV) catalysts. We proved the
stability of these performances over 40 hours without decline. These results
could open a new path for designing efficient and stable catalysts.
