Particle size-control enables extraordinary activity of ruthenium nanoparticles/multiwalled carbon nanotube catalysts towards the oxygen reduction reaction.
Chang LiuGailing BaiZhifeng JiaoBaoying LvYunwei WangXili TongNianjun YangPublished in: Nanoscale (2019)
Catalysts with high efficiency for the oxygen reduction reaction (ORR) play a vital important role in fuel cells and metal-air batteries. Herein, Ru nanoparticles are highly dispersed on functional multi-walled carbon nanotubes (MWCNTs) by a facile impregnation-reduction method. The particle sizes of Ru nanoparticles are simply and effectively adjusted by the concentration of the Ru precursor. Benefiting from the optimal Ru particle size (2.1 nm), a large electrochemically active surface area and fast electron transport, the Ru/MWCNT catalyst shows outstanding ORR activity and durability via a four-electron pathway, producing a diffusion-limited current density of 4.7 mA cm-2 with a half-wave potential of 0.72 V (vs. RHE). Such performance is better than that of a commercial 10 wt% Pt/C catalyst. Density functional theory calculation results reveal that the Oads adsorption on the surface of Ru increases gradually with the addition of the RuOx layer. The Ru/MWCNT catalyst with a particle size of 2.1 nm features appropriate Oads adsorption energy due to the formation of an optimal RuOx/Ru interface for the facilitation of the ORR.
Keyphrases
- energy transfer
- walled carbon nanotubes
- highly efficient
- density functional theory
- metal organic framework
- high efficiency
- reduced graphene oxide
- ionic liquid
- carbon nanotubes
- room temperature
- photodynamic therapy
- induced apoptosis
- molecular dynamics
- carbon dioxide
- cell proliferation
- visible light
- climate change
- single cell
- oxidative stress
- pi k akt