Ruthenium-Tungsten Composite Catalyst for the Efficient and Contamination-Resistant Electrochemical Evolution of Hydrogen.
Ubisha JoshiSouradip MalkhandiYi RenTeck Leong TanSing Yang ChiamBoon Siang YeoPublished in: ACS applied materials & interfaces (2018)
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 H2SO4 electrolyte, this catalyst, which contained a miniscule loading of 2-5 nm sized Ru nanoparticles (5.6 μg Ru per cm2 of geometric surface area of the working electrode), required an overpotential of only 85 mV to drive 10 mA/cm2 of H2 evolution. Interestingly, our catalyst also exhibited good immunity against deactivation during HER from ionic contaminants, such as Cu2+ (over 24 h). We unravel the mechanism of synergy between W and Ru for catalyzing H2 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.
Keyphrases
- ionic liquid
- density functional theory
- energy transfer
- room temperature
- molecular dynamics
- metal organic framework
- reduced graphene oxide
- highly efficient
- gold nanoparticles
- carbon dioxide
- aqueous solution
- risk assessment
- high resolution
- molecular docking
- mental health
- solid state
- photodynamic therapy
- mass spectrometry
- molecular dynamics simulations
- quantum dots
- human health
- climate change
- electron transfer
- crystal structure
- health risk