Universal Electrode Interface for Electrocatalytic Oxidation of Liquid Fuels

Abstract

Electrocatalytic oxidations of liquid fuels from alcohols, carboxylic acids, and aldehydes were realized on a universal electrode interface. Such an interface was fabricated using carbon nanotubes (CNTs) as the catalyst support and palladium nanoparticles (Pd NPs) as the electrocatalysts. The Pd NPs/CNTs nanocomposite was synthesized using the ethylene glycol reduction method. It was characterized using transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, voltammetry, and impedance. On the Pd NPs/CNTs nanocomposite coated electrode, the oxidations of those liquid fuels occur similarly in two steps: the oxidations of freshly chemisorbed species in the forward (positive-potential) scan and then, in the reverse scan (negative-potential), the oxidations of the incompletely oxidized carbonaceous species formed during the forward scan. The oxidation charges were adopted to study their oxidation mechanisms and oxidation efficiencies. The oxidation efficiency follows the order of aldehyde (formaldehyde) > carboxylic acid (formic acid) > alcohols (ethanol > methanol > glycol > propanol). Such a Pd NPs/CNTs nanocomposite coated electrode is thus promising to be applied as the anode for the facilitation of direct fuel cells.

Nitrogen-doped porous carbon sphere supported Pt nanoparticles for methanol and ethanol electro-oxidation in alkaline media

“…The peaks in the forward scan correspond to the oxidation of alcohol on the catalyst, while those in the backward scan are due to the oxidation of intermediate products produced from the forward scan. 35 It can clearly be observed that Pt/MNCS exhibits a higher electro-catalytic activity than Pt/C for the oxidation of both methanol and ethanol. The electrochemical performance parameters of different catalysts were compared and are summarized in Table 1 .…”

Structure‐Performance Relationship of LaFe1‐xCoxO3Electrocatalysts for Oxygen Evolution, Isopropanol Oxidation, and Glycerol Oxidation

“…For the aforementioned reactions, high‐performance electrocatalysts were reported which made use of noble metal‐based materials, for example Ir and Ru oxides in case of the OER, [10–12] and Pt, Pd and Au‐based materials for the iPOR [4,13–20] and the GOR [5,21–32] . However, in addition to their scarcity and expensiveness, their severe CO poisoning [33,34] is problematic for alcohol oxidation as for these reactions all intermediates contain CO species [5,6] .…”

“…[5,6] For example, lactic acid finds applications in different industries such as food, cosmetics, textiles and dairy as pH regulator, preservative, antibacterial and moisturiser, [7] while glycolic acid serves as a degreasing agent and is used in skin care products. [8,9] For the aforementioned reactions, high-performance electrocatalysts were reported which made use of noble metalbased materials, for example Ir and Ru oxides in case of the OER, [10][11][12] and Pt, Pd and Au-based materials for the iPOR [4,[13][14][15][16][17][18][19][20] and the GOR. [5,[21][22][23][24][25][26][27][28][29][30][31][32] However, in addition to their scarcity and expensiveness, their severe CO poisoning [33,34] is problematic for alcohol oxidation as for these reactions all intermediates contain CO species.…”

Bio‐Based Graphene Sheet/Copolymer Composite as Supporting Material for Nanocatalysts towards Electrochemical Studies and Direct Alkaline Alcohol Fuel Cells

“…The catalyst's activity and stability of alcohol oxidation in alkaline medium depend not only on the presence of metal nanoparticles but also on the properties of support material and interactions between the metal particles and support materials. Generally, conductive polymers [11]; carbon-based materials like graphene, carbon nanotubes, carbon fibers, and mesoporous carbon [12][13][14][15]; metal sulfides [16]; and zeolites [17] are used as catalyst supports for various applications.…”