1 research outputs found
Ruthenium–Tungsten Composite Catalyst for the Efficient and Contamination-Resistant Electrochemical Evolution of Hydrogen
A new
catalyst, prepared by a simple physical mixing of ruthenium (Ru) and
tungsten (W) powders, has been discovered to interact synergistically to enhance the electrochemical
hydrogen evolution reaction (HER). In an aqueous 0.5 M H<sub>2</sub>SO<sub>4</sub> electrolyte, this catalyst, which contained a miniscule
loading of 2–5 nm sized Ru nanoparticles (5.6 μg Ru per
cm<sup>2</sup> of geometric surface area of the working electrode),
required an overpotential of only 85 mV to drive 10 mA/cm<sup>2</sup> of H<sub>2</sub> evolution. Interestingly, our catalyst also exhibited
good immunity against deactivation during HER from ionic contaminants,
such as Cu<sup>2+</sup> (over 24 h). We unravel the mechanism of synergy
between W and Ru for catalyzing H<sub>2</sub> evolution using Cu underpotential
deposition, photoelectron spectroscopy, and density functional theory
(DFT) calculations. We found a decrease in the d-band and an increase
in the electron work function of Ru in the mixed composite, which
made it bind to H more weakly (more Pt-like). The H-adsorption energy
on Ru deposited on W was found, by DFT, to be very close to that of
Pt(111), explaining the improved HER activity