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There is an urgent need for cost‐effective strategies to produce hydrogen from renewable net‐zero carbon sources using renewable energies. In this context, the electrochemical hydrogen evolution reaction can be boosted by replacing the oxygen evolution reaction with the oxidation of small organic molecules, such as ethylene glycol (EG). EG is a particularly interesting organic liquid with two hydroxyl groups that can be transformed into a variety of C1 and C2 chemicals, depending on the catalyst and reaction conditions. Here, a catalyst is demonstrated for the selective EG oxidation reaction (EGOR) to formate on nickel selenide. The catalyst nanoparticle (NP) morphology and crystallographic phase are tuned to maximize its performance. The optimized NiS electrocatalyst requires just 1.395 V to drive a current density of 50 mA cm−2 in 1 m potassium hydroxide (KOH) and 1 m EG. A combination of in situ electrochemical infrared absorption spectroscopy (IRAS) to monitor the electrocatalytic process and ex situ analysis of the electrolyte composition shows the main EGOR product is formate, with a Faradaic efficiency above 80%. Additionally, C2 chemicals such as glycolate and oxalate are detected and quantified as minor products. Density functional theory (DFT) calculations of the reaction process show the glycol‐to‐oxalate pathway to be favored via the glycolate formation, where the CC bond is broken and further electro‐oxidized to formate. A combination of in situ and ex situ analysis shows the main product of the ethylene glycol (EG) oxidation reaction (EGOR) is formate with a Faradaic efficiency above 80%, and glycolate and oxalate as minor chemicals on nickel selenide nanoparticles (NPs). Further density functional theory (DFT) calculation reveals the electrooxidation mechanism to these products.

In this work, mandarin peel‐derived biocarbons synthesized by fast pyrolysis are tested as support materials for PtPd nanoparticles for the electrochemical oxidation of glycerol in an alkaline electrolyte. The biocarbons, synthesized at 300 °C (mandarin peel‐derived biocarbons (BCM)‐300) and 500 °C (BCM‐500), present good electronic conductivities and adequate surface properties. Bimetallic PtPd nanoparticles with average sizes between 3.5 and 3.9 nm and a Pt:Pd ratio of 3:1 are deposited over the biocarbons by a pulse microwave‐assisted polyol method. The electrochemical experiments show that the mass‐specific activity for the glycerol oxidation reaction of the PtPd particles supported over the biocarbons is higher than that reported for the bimetallic catalyst deposited over Vulcan carbon black. In addition, the catalyst deposited over the biocarbons presents lower potential onsets, lower apparent activation energies, and lower charge transfer resistances compared to the bimetallic particles supported over the commercial carbon material. The superior electrocatalytic performance of PtPd/BCM‐300 and PtPd/BCM‐500 catalysts is attributed to the synergistic effect between the bimetallic particles and the biocarbons, which promotes glycerol oxidation through both the electronic effects and the bifunctional mechanism. Mandarin peel‐derived biocarbons (BCM) are prepared via fast pyrolysis at low temperatures. BCM powders are used as support for the preparation of PtPd catalysts. PtPd/BCM catalysts perform better for the glycerol oxidation reaction (GOR) than the bimetallic system supported on Vulcan. It is observed that BCM supports induce a strong metal–support interaction and supply labile –OH groups for the oxidation of the adsorbed intermediates during the GOR process.

Tetracycline hydrochloride (TCH) electro-oxidation by commercial DSA® and commercial DSA® modified by platinum electrodeposition was evaluated. The electrodeposition was carried out at constant potential ( E  = − 0.73 V vs RHE) in different times (1200, 2400, and 4800 s). Scanning electron microscopy (SEM) images show that Pt electrodeposits have elongated shape particle forming a uniform surface, and energy dispersive spectroscopy (EDS) data confirms the presence of Pt on the surface. The electrochemical characterization by cyclic voltammetry showed an increase of the electrochemically active area ( E AA ) in function of the Pt electrodeposition time. The electro-oxidation of the TCH 0.45 mmol L −1 in H 2 SO 4 0.1 mol L −1 solution was evaluated according to the applied current densities ( j  = 25, 50, 100 mA cm −2 ). Both the amount of platinum deposited and j showed a slight improvement in the efficiency of TCH removal, reaching 97.2% of TCH removal to DSA®/Pt 4800 and 100 mA cm −2 . The TCH mineralization (TOC removal), the percentage of mineralization current efficiency (MCE%), and energy consumption were 15.8%, 0.2649%, and 7.4138 kWh (g TOC) −1 , respectively. The DSA®/Pt electrodes showed higher stability to TCH electro-oxidation, indicating to be a promising material for the electro-oxidation of organic pollutants.

Glycerol is a cheap, non‐toxic, and renewable by‐product of the rapid expansion of biodiesel and soap producers around the world. Glycerol electroforming is a method of oxidizing glycerol into valuable chemicals of interest to the pharmaceutical, cosmetics, polymer, and food industries. One of the technologies that have been studied over the past decades is to couple glycerol oxidation with the production of pure hydrogen in an electrolysis cell (so‐called electrolyzer), which has shown the advantage of consuming a much lower theoretical amount of electricity than conventional water electrolysis. The efficiency of this device is influenced by the nature, structure, and composition of the electrode material. This mini‐review concerns the understanding of glycerol electro‐oxidation, a brief state of the art of nanomaterials currently used to prepare electrode materials, and some results concerning the performance of electrolyzers in alkaline conditions that combine the efficient production of value‐added chemicals and hydrogen.

CO impurity‐induced catalyst deactivation has long been one of the biggest challenges in proton‐exchange membrane fuel cells, with the poisoning phenomenon mainly attributed to the overly strong adsorption on the catalytic site. Here, we present a mechanistic study that overturns this understanding by using Rh‐based single‐atom catalysis centers as model catalysts. We precisely modulated the chelation structure of the Rh catalyst by coordinating Rh with C or N atoms, and probed the reaction mechanism by surface‐enhanced Raman spectroscopy. Direct spectroscopic evidence for intermediates indicates that the reactivity of adsorbed OH*, rather than the adsorption strength of CO*, dictates the CO electrocatalytic oxidation behavior. The RhN 4 sites, which adsorb the OH* intermediate more weakly than RhC 4 sites, showed prominent CO oxidation activity that not only far exceeded the traditional Pt/C but also the RhC 4 sites with similar CO adsorption strength. From this study, it is clear that a paradigm shift in future research should be considered to rationally design high‐performance CO electro‐oxidation reaction catalysts by sufficiently considering the water‐related reaction intermediate during catalysis.

Heterogeneous nanocomposites comprising chemically distinct constituents are particularly promising in electrocatalysis. We herein report a synthetic strategy that combines the reduction of Pt and Co ionic precursors at an appropriate ratio with the subsequent phosphating at an elevated temperature for forming heterogeneous nanocomposites consisting of quasi‐spherical Pt3Co alloy domains and rod‐like CoP2 domains for high‐efficiency methanol electro‐oxidation. The strong electronic coupling between Pt3Co and CoP2 domains in the nanocomposites render the electron density around Pt atoms to decrease, which is favorable for reducing the adsorption of poisoning CO‐like intermediates on the catalyst surfaces. Accordingly, the as‐prepared heterogeneous Pt3Co–CoP2 nanocomposites show good performance for methanol electro‐oxidation both in acidic and alkaline media. In specific, at a Pt loading of only 6.4% on a common carbon substrate, the mass‐based activity of Pt3Co–CoP2 nanocomposites in an acidic medium is about 2 and 1.5 times as high as that of commercial Pt/C catalyst (20% mass loading) and home‐made Pt3Co alloy nanoparticles (8.0% mass loading), while in the alkaline medium, these values are 3 and 2, respectively. Heterogeneous Pt3Co–CoP2 nanocomposites with favorable electronic configuration could weaken the absorption of poisoning CO‐like intermediates, which significantly boosts their catalytic activity and durability for the electrocatalytic oxidation of methanol.

Due to their environmentally friendly nature and high energy density, direct ethanol fuel cells have attracted extensive research attention in recent decades. However, the actual Faraday efficiency of the ethanol oxidation reaction (EOR) is much lower than its theoretical value and the reaction kinetics of the EOR is sluggish due to insufficient active sites on the electrocatalyst surface. Pt/C is recognized as one of the most promising electrocatalysts for the EOR. Thus, the microscopic interfacial reaction mechanisms of the EOR on Pt/C were systematically studied in this work. In metal hydroxide solutions, hydrated alkali cations were found to bind with OH ad through noncovalent interactions to form clusters and occupy the active sites on the Pt/C electrocatalyst surface, thus resulting in low Faraday efficiency and sluggish kinetics of the EOR. To reduce the negative effect of the noncovalent interactions on the EOR, a shield was made on the electrocatalyst surface using 4‐trifluoromethylphenyl, resulting in twice the EOR catalytic reactivity of Pt/C.

A high methanol electro-oxidation (MOR) and carbon monoxide (CO) tolerance satisfied the electrochemical requirements of direct methanol fuel cells (DMFCs). The study investigated strontium molybdate (SrMoO4) mixed with Vulcan XC-72, carbon-loaded with 20% Pt. The electrochemical performance was confirmed by MOR and CO tolerance activities measured via cyclic voltammetry (CV). The synergistic effect between Pt and SrMoO4 is essential to affect the electrochemical characteristic. SrMoO4 can help remove CO-like intermediate products on the Pt surface, enhancing electrochemical performance for DMFCs. In addition, HxMoO3/HyMoO3 existence in Sr0.5Mo0.5O4−δ can quickly remove intermediates from Pt surfaces and accelerate the transformation of adsorbed intermediates to CO2. The results obtained showed that 20%-Pt/uncalcined Sr0.5Mo0.5O4−δ-C electrocatalyst has higher MOR and CO tolerance ability in DMFCs. Furthermore, the fabricated DMFC shows excellent long-term electrochemical stability after 1000 cycles and a maximum power density (1.42 mW/cm2) higher than commercial 20%-Pt/C (1.27 mW/cm2).

Salicylaldehyde (SA) is used in numerous biological, pharmaceutical, and industrial applications. Releasing effluents from these industries contaminates water. So the degradation of salicylaldehyde is necessitated. The electrochemical degradation of salicylaldehyde in buffered media was studied using the eco-friendly cyclic voltammetry (CV) technique on a platinum electrode at different scan rates. Kinetic and electrochemical parameters were evaluated for the reaction such as standard heterogeneous rate constant (k0,2.468×103 s-1 ), anodic electron transfer rate constant (kox,2.507×103 s-1), electron transfer coefficient of reaction (?,0.673), and formal potential (E0, 1.0937) under the influence of scan rate. The nature of the reaction is found to be diffusion controlled. The concentration study in the range of 1 mM to 4 mM was calibrated. The limit of detection and the limit of quantification were calculated to be 0.0031 mM and 0.0103 mM respectively.

By combining the hydrothermal and pulsed laser deposition methods, several three‐dimensional Pt catalysts on TiO2 structures are prepared and used for the electro‐oxidation of ethanol in acidic medium. SEM reveals that TiO2 prepared with 0.6 M of HCl consist of a mixture of nanowires and nanorods. For higher HCl concentrations, the TiO2 are either in the form of vertically aligned bars or large branched crystals in the form of flowers‐like. Despite having the same loading of Pt, among the 3D Pt/TiO2/Ti structures, only those with TiO2 prepared with 0.6 M of HCl shows a higher area specific activity and current mass activities exceptionally superior of about >50 times than those of unsupported Pt/Ti catalyst toward ethanol oxidation reaction, which suggests a promising application in ethanol fuel cells. The combination of hydrothermal synthesis and pulser laser deposition technique allowed to construct three‐dimensional Pt catalysts on TiO2 structures. These 3D structured catalysts displayed higher area specific activity and current mass activities exceptionally superior of about more than 50 times than those of unsupported Pt/Ti catalyst towards ethanol oxidation reaction, a reaction of technological importance for direct ethanol fuel cells.