Investigation of the electrocatalytic activity for ethanol oxidation of Pt nanoparticles modified with small amount (≤5 wt%) of CeO2

Research on UO2 modification of a direct ethanol fuel cell Pt/C catalyst

Radioactive UO₂ powder was prepared by hydrothermal method and a set of Pt–xUO₂/C catalysts were synthesized by impregnation method for solving the problem of low activity and easy poisoning of anode Pt/C catalysts for a direct ethanol fuel cell. XRD, TEM, EDS, XPS and ICP-MS characterization showed the successful loading of Pt and UO₂ onto the carbon carrier. Electrochemical workstation and single cell test results confirm that the catalytic performance of Pt–10% UO₂/C is significantly better than Pt/C-eg. It is speculated that the synergistic effect of Pt and U enhances the catalytic activity and UO₂ improves the resistance to CO poisoning by releasing O₂ stored in the lattice space, while the α-particles released by ²³⁵U can also generate radiolysis product OH and promote the oxidative desorption of CO from the Pt surface.

The Pt–xUO₂/C catalyst modified by UO₂ in DEFC shows better catalytic activity, durability and resistance to CO poisoning ability than the anode Pt/C catalyst.

A comprehensive and critical review of the recent progress in electrocatalysts for the ethanol oxidation reaction

The human craving for energy is continually mounting and becoming progressively difficult to gratify. At present, the world's massive energy demands are chiefly encountered by nonrenewable and benign fossil fuels. However, the development of dynamic energy cradles for a gradually thriving world to lessen fossil fuel reserve depletion and environmental concerns is currently a persistent issue for society. The discovery of copious nonconventional resources to fill the gap between energy requirements and supply is the extreme obligation of the modern era. A new emergent, clean, and robust alternative to fossil fuels is the fuel cell. Among the different types of fuel cells, the direct ethanol fuel cell (DEFCs) is an outstanding option for light-duty vehicles and portable devices. A critical tactic for obtaining sustainable energy sources is the production of highly proficient, economical and green catalysts for energy storage and conversion devices. To date, a broad range of research is available for using Pt and modified Pt-based electrocatalysts to augment the C₂H₅OH oxidation process. Pt-based nanocubes, nanorods, nanoflowers, and the hybrids of Pt with metal oxides such as Fe₂O₃, TiO₂, SnO₂, MnO, Cu₂O, and ZnO, and with conducting polymers are extensively utilized in both acidic and basic media. Moreover, Pd-based materials, transition metal-based materials, as well as transition metal-based materials are also points of interest for researchers nowadays. This review article delivers a broad vision of the current progress of the EOR process concerning noble metals and transition metals-based materials.

Well-defined polyindole–Au NPs nanobrush as a platform for electrochemical oxidation of ethanol

Over the recent decades, conducting polymers have received great interest in many fields including microelectronics, energy conversion devices, and biosensing due to their unique properties like electrical conductivity, stability, and simple synthesis. Modification of conducting polymers with noble metals e.g. gold enhances their properties and opens new opportunities to also apply them in other fields like electrocatalysis. Here, we focus on the synthesis of hybrid material based on polyindole (PIN) nanobrush modified with gold nanoparticles and its application towards electrooxidation of ethanol. The paper presents systematic studies from synthesis to electrochemical sensing applications. For the characterization of PIN–Au composites, scanning electron microscopy and X-ray diffraction analyses were used. The electrocatalytic performance of the proposed hybrid material towards alcohol oxidation was studied in alkaline media by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy techniques. The results show that PIN–Au hybrid can be employed as an effective and sensitive platform for the detection of alcohols, which makes it a promising material in electrocatalysis or sensors. Moreover, the proposed composite exhibits electrocatalytic activity towards ethanol oxidation, which combined with its good long-term stability opens the opportunity for its application in fuel cells.

Ethanol Electrooxidation at Platinum-Rare Earth (RE = Ce, Sm, Ho, Dy) Binary Alloys

Proton exchange membrane fuel cells and direct alcohol fuel cells have been extensively studied over the last three decades or so. They have emerged as potential systems to power portable applications, providing clean energy, and offering good commercial viability. Ethanol is considered one of the most interesting fuels in this field. Herein, platinum-rare earth (Pt-RE) binary alloys (RE = Ce, Sm, Ho, Dy, nominal composition 50 at.% Pt) were produced and studied as anodes for ethanol oxidation reaction (EOR) in alkaline medium. A Pt-Dy alloy with nominal composition 40 at.% Pt was also tested. Their electrocatalytic performance was evaluated by voltammetric and chronoamperometric measurements in 2 M NaOH solution with different ethanol concentrations (0.2–0.8 M) in the 25–45 °C temperature range. Several EOR kinetic parameters were determined for the Pt-RE alloys, namely the charge transfer and diffusion coefficients, and the number of exchanged electrons. Charge transfer coefficients ranging from 0.60 to 0.69 and n values as high as 0.7 were obtained for the Pt0.5Sm0.5 electrode. The EOR reaction order at the Pt-RE alloys was found to vary between 0.4 and 0.9. The Pt-RE electrodes displayed superior performance for EOR than bare Pt, with Pt0.5Sm0.5 exhibiting the highest electrocatalytic activity. The improved electrocatalytic activity in all of the evaluated Pt-RE binary alloys suggests a strategy for the solution of the existing anode issues due to the structure-sensitive EOR.

Advanced Catalytic Materials for Ethanol Oxidation in Direct Ethanol Fuel Cells

Direct ethanol fuel cells (DEFCs) have emerged as promising and advanced power systems that can considerably reduce fossil fuel dependence, and thus have attracted worldwide attention. DEFCs have many apparent merits over the analogous devices fed with hydrogen or methanol. As the key constituents, the catalysts for both cathodes and anodes usually face some problems (such as high cost, low conversion efficiency, and inferior durability) that hinder the commercialization of DEFCs. This review mainly focuses on the most recent advances in nanostructured catalysts for anode materials in DEFCS. First, we summarize the effective strategies used to achieve highly active Pt- and Pd-based catalysts for ethanol electro-oxidation, including composition control, microstructure design, and the optimization of support materials. Second, a few non-precious catalysts based on transition metals (such as Fe, Co, and Ni) are introduced. Finally, we outline the concerns and future development of anode catalysts for DEFCs. This review provides a comprehensive understanding of anode catalysts for ethanol oxidation in DEFCs.