Boosted formic acid electro-oxidation on platinum nanoparticles and "mixed-valence" iron and nickel oxides.
Bilquis Ali Al-QodamiSayed Youssef SayedHafsa H AlalawyIslam M Al-AkraaNageh K AllamAhmad M MohammadPublished in: RSC advances (2023)
The modification of Pt nanoparticles (nano-Pt, assembled electrochemically onto a glassy carbon (GC) substrate) with hybrid multivalent nickel (nano-NiO x ) and iron (nano-FeO x ) oxide nanostructures was intended to steer the mechanism of the formic acid electro-oxidation (FAO) in the desirable dehydrogenation pathway. This binary modification with inexpensive oxides succeeded in mediating the reaction mechanism of FAO by boosting reaction kinetics "electron transfer" and amending the surface geometry of the catalyst against poisoning. The sequence of deposition was optimized where the a-FeO x /NiO x /Pt/GC catalyst (where "a" denotes a post-activation step for the catalyst at -0.5 V in 0.5 mol L -1 NaOH) reserved the best hierarchy. Morphologically, while nano-Pt appeared to be spherical ( ca. 100 nm in average diameter), nano-NiO x appeared as flowered nanoaggregates ( ca. 56 nm in average diameter) and nano-FeO x (after activation) retained a plate-like nanostructure ( ca. 38 nm in average diameter and 167 nm in average length). This a-FeO x /NiO x /Pt/GC catalyst demonstrated a remarkable catalytic efficiency (125 mA mg Pt -1 ) for FAO that was ca. 12.5 times that of the pristine Pt/GC catalyst with up to five times improvement in the catalytic tolerance against poisoning and up to -214 mV shift in the FAO's onset potential. Evidences for equipping the a-FeO x /NiO x /Pt/GC catalyst with the least charge transfer resistance and the highest stability among the whole investigated catalysts are provided and discussed.
Keyphrases
- reduced graphene oxide
- metal organic framework
- ionic liquid
- highly efficient
- room temperature
- electron transfer
- visible light
- photodynamic therapy
- carbon dioxide
- gold nanoparticles
- gas chromatography
- optic nerve
- nitric oxide
- protein kinase
- walled carbon nanotubes
- carbon nanotubes
- atomic force microscopy
- amino acid
- light emitting
- single molecule
- crystal structure
- liquid chromatography
- tandem mass spectrometry
- solid phase extraction