Electrocatalytic Study of Ethylene Glycol Oxidation on Pt 3 Sn Alloy Nanoparticles

Potential cycling boosts the electrochemical conversion of polyethylene terephthalate-derived alcohol into valuable chemicals

The electrocatalytic valorization of polyethylene terephthalate-derived ethylene glycol to valuable glycolic acid offers considerable economic and environmental benefits. However, conventional methods face scalability issues due to rapid activity decay of noble metal electrocatalysts. We demonstrate that a dynamic potential cycling approach, which alternates the electrode potential between oxidizing and reducing values, significantly mitigates surface deactivation of noble metals during electrochemical oxidation of ethylene glycol. This method enhances catalyst activity by 20 times compared to a constant-potential approach, maintaining this performance for up to 60 h with minimal deactivation. In situ Raman and X-ray absorption spectroscopy show that this effectiveness results from efficient removal of surface oxide during the reaction. The strategy is applicable to polyethylene terephthalate hydrolysates and various noble metals, such as palladium, gold, and platinum, with palladium showing a high conversion rate in recent studies. Our approach offers an efficient and durable method for electrochemical upcycling of biomass-derived compounds.

Carbon Nanotube PtSn Nanoparticles for Enhanced Complete Biocatalytic Oxidation of Ethylene Glycol in Biofuel Cells

We report a hybrid catalytic system containing metallic PtSn nanoparticles deposited on multiwalled carbon nanotubes (Pt₆₅Sn₃₅/MWCNTs), prepared by the microwave-assisted method, coupled to the enzyme oxalate oxidase (OxOx) for complete ethylene glycol (EG) electrooxidation. Pt₆₅Sn₃₅/MWCNTs, without OxOx, showed good electrochemical activity toward EG oxidation and all the byproducts. Pt₆₅Sn₃₅/MWCNTs cleaved the glyoxilic acid C-C bond, producing CO₂ and formic acid, which was further oxidized at the electrode. Concerning EG oxidation, the catalytic activity of the hybrid system (Pt₆₅Sn₃₅/MWCNTs+OxOx) was twice the catalytic activity of Pt₆₅Sn₃₅/MWCNTs. Long-term electrolysis revealed that Pt₆₅Sn₃₅/MWCNTs+OxOx was much more active for EG oxidation than Pt₆₅Sn₃₅/MWCNTs: the charge increased by 65%. The chromatographic results proved that Pt₆₅Sn₃₅/MWCNTs+OxOx collected all of the 10 electrons per molecule of the fuel and was able to catalyze EG oxidation to CO₂ due to the associative oxidation between the metallic nanoparticles and the enzymatic pathway. Overall, Pt₆₅Sn₃₅/MWCNTs+OxOx proved to be a promising system to enhance the development of enzymatic biofuel cells for further application in the bioelectrochemistry field.

Effect of Anode Material on Electrochemical Oxidation of Low Molecular Weight Alcohols-A Review

The growing climate crisis inspires one of the greatest challenges of the 21st century-developing novel power sources. One of the concepts that offer clean, non-fossil electricity production is fuel cells, especially when the role of fuel is played by simple organic molecules, such as low molecular weight alcohols. The greatest drawback of this technology is the lack of electrocatalytic materials that would enhance reaction kinetics and good stability under process conditions. Currently, electrodes for direct alcohol fuel cells (DAFCs) are mainly based on platinum, which not only provides a poor reaction rate but also readily deactivates because of poisoning by reaction products. Because of these disadvantages, many researchers have focused on developing novel electrode materials with electrocatalytic properties towards the oxidation of simple alcohols, such as methanol, ethanol, ethylene glycol or propanol. This paper presents the development of electrode materials and addresses future challenges that still need to be overcome before direct alcohol fuel cells can be commercialized.

Facet-Dependent Long-Term Stability of Gold Aerogels toward Ethylene Glycol Oxidation Reaction

In this work, a series of Au_PNR^6 - 50 aerogels with different percentages of {110} facets (from ∼12 to 36%) were controllably prepared and then used to investigate their performance (specific activity and long-term stability) toward ethylene glycol oxidation reaction (EGOR), in which PNR represents the particle number ratio of 6 nm Au NPs to 50 nm Au NPs. It is found that their specific activity and long-term stability highly depend on the sum of the percentage of the {100} and {111} facets and the percentage of {110} facets, respectively. In addition, Au₂₄^6 - 50 aerogels with the highest percentage of {110} facets can possess excellent long-term stability (retaining about 95% of the initial current) but still have excellent specific activity (about 90.42 mA cm^-2). Thus, the specific activity and long-time stability of Au_PNR^6 - 50 aerogels toward EGOR can be well balanced by controlling the proper percentage of {110} facets on their surfaces. Therefore, the successful fabrication of Au_PNR^6 - 50 aerogels with greatly improved long-term stability and excellent specific activity not only provides a novel method for the design of electrocatalysts but also would boost the commercial development of direct ethylene glycol fuel cells.

Electrochemical pretreatment of coal gasification wastewater with Bi-doped PbO2 electrode: Preparation of anode, efficiency and mechanism

Coal gasification wastewater (CGW) contains a large amount of toxic pollutants, which seriously affects the subsequent biochemical treatment. In order to investigate the efficiency of electrocatalytic oxidation on pretreatment of CGW, lead dioxide electrodes doped with PEG and Bi were successfully prepared. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were comprehensively used to characterize the lead dioxide electrode and the electrochemical performance was also tested by linear sweep voltammetry curve, cyclic voltammetry curve and AC impedance. Biodegradability and toxicity of CGW were evaluated by dehydrogenase activity and acute toxicity, respectively. Results showed that the doping of PEG and Bi significantly improved the electrochemical performance and catalytic oxidation performance of lead dioxide electrodes. The degradation rate of phenol by Sn-Sb/PbO₂ (PEG + Bi) electrode were 1.57 times of that by pure lead dioxide electrode. The removal of TOC and total phenols were 53.2% and 82.7%, respectively at 120 min under 40 mA cm^-2 by Sn-Sb/PbO₂ (PEG + Bi) electrode. The changes of biodegradability, biological toxicity and by-products were analyzed. Furthermore, 3,5-dimethylphenol was used as characteristic pollutant to study the degradation mechanism of phenolic pollutants in electrocatalytic system. According to the intermediate products detected by GC-MS, possible degradation pathways in electrocatalytic system were proposed.

Platinum–palladium alloy nanotetrahedra with tuneable lattice-strain for enhanced intrinsic activity

Understanding how to regulate lattice strain of PtPd NTDs and the correlation of PtPd NTDs between the compositions, tuneable lattice strain and the electrocatalytic properties.