Glassy Carbon Surface Research Articles

Electrocatalytic Hydrogen Evolution Reaction from Acetic Acid over Gold Immobilized Glassy Carbon Surface

A hydrogen fuel cell is a highly promising alternative to fossil fuel sources owing to the emission of harmless byproducts. However, the operation of hydrogen fuel cells requires a constant supply of highly pure hydrogen gas. The scarcity of sustainable methods of producing such clean hydrogen hinders its global availability. In this work, a noble Au-atom-decorated glassy carbon electrode (Au/GCE) was prepared via a conventional electrodeposition technique and used to investigate the generation of hydrogen from acetic acid (AA) in a neutral electrolyte using 0.1 M KCl as the supporting electrolyte. Electrochemical impedance spectroscopy (EIS), open circuit potential measurement, cyclic voltammetry (CV), and rotating disk electrode voltammetry (RDE) were performed for the characterization and investigation of the catalytic properties. The constructed catalyst was able to produce hydrogen from acetic acid at a potential of approximately −0.2 V vs. RHE, which is much lower than a bare GCE surface. According to estimates, the Tafel slope and exchange current density are 178 mV dec−1 and 7.90×10−6 A cm−2, respectively. Furthermore, it was revealed that the hydrogen evolution reaction from acetic acid has a turnover frequency (TOF) of approximately 0.11 s−1.

Biocatalysis versus Molecular Recognition in Sialoside-Selective Neuraminidase Biosensing.

Sialic acid recognition and hydrolysis are essential parts of cellular function and pathogen infectivity. Neuraminidases are enzymes that detach sialic acid from sialosides, and their inhibition is a prime target for viral infection treatment. The connectivity and type of sialic acid influence the recognition and hydrolysis activity of the many different neuraminidases. The common strategies to evaluate neuraminidase activity, recognition, and inhibition rely on extensive labeling and require a large amount of sialylated glycans. The above limitations make the effort of finding viral inhibitors extremely difficult. We used synthetic sialylated glycans and developed a label-free electrochemical method to show that sialoside structural features lead to selective neuraminidase biosensing. We compared Neu5Ac to Neu5Gc sialosides to evaluate the organism-dependent neuraminidase selectivity-sensitivity relationship. We demonstrated that the type of surface and the glycan monolayer density direct the response to either binding or enzymatic activity. We proved that while the hydrophobic glassy carbon surface increases the interaction with the enzyme hydrophobic interface, the negatively charged interface of the lipoic acid monolayer on gold repels the protein and enables biocatalysis. We showed that the sialoside monolayers can serve as tools to evaluate the inhibition of neuraminidases both by biocatalysis and molecular recognition.

Development of Polydiphenylamine@Electrochemically Reduced Graphene Oxide Electrode for the D-Penicillamine Sensor from Human Blood Serum Samples Using Amperometry.

D-penicillamine (PA) is a sulfur group-containing drug prescribed for various health issues, but overdoses have adverse effects. Therefore, regular, selective, and sensitive sensing is essential to reduce the need for further treatment. In this study, diphenylamine (DPA) was electropolymerized in an aqueous acidic medium. The PA detection sensitivity, selectivity, and limit of detection were enhanced by electropolymerizing DPA on an electrochemically reduced graphene oxide (ERGO)/glassy carbon (GC) surface. The formation of p-DPA and ERGO was investigated using various techniques. The as-prepared p-DPA@ERGO/GC revealed the excellent redox-active (N-C to N=C) sites of p-DPA. The p-DPA@ERGO/GC electrode exhibited excellent electrochemical sensing ability towards PA determination because of the presence of the -NH-functional moiety and effective interactions with the -SH group of PA. The p-DPA@ERGO/GC exhibited a high surface coverage of 9.23 × 10-12 mol cm-2. The polymer-modified p-DPA@ERGO/GC electrode revealed the amperometric determination of PA concentration from the 1.4 to 541 μM wide range and the detection limit of 0.10 μM. The real-time feasibility of the developed p-DPA@ERGO/GC electrode was tested with a realistic PA finding in human blood serum samples and yielded a good recovery of 97.5-101.0%, confirming the potential suitability in bio-clinical applications.

Glassy Carbon Neural Interface for Chronic Epidural Stimulation in Rats with Cervical Spinal Cord Injury.

There is growing evidence on the efficacy of electrical stimulation delivered via spinal neural interfaces to improve functional recovery following spinal cord injury. For such interfaces, carbon-based neural arrays are fast becoming recognized as a compelling material and platform due to biocompatibility and long-term electrochemical stability. Here, we introduce the design, fabrication, and in vivo characterization of a novel cervical epidural implant with carbon-based surface electrodes. Through finite element analysis and mechanical load tests, we demonstrated that the array could safely withstand loads applied to it during implantation and natural movement of the subject with minimal stress levels. Furthermore, the long-term in vivo performance of this neural array consisting of glassy carbon surface electrodes was investigated through acute and chronic spinal motor evoked potential recordings and electrode impedance tests in rats. We demonstrated stable stimulation performance for at least four weeks in a rat model of spinal cord injury. Lastly, we found that impedance measurements on all carbon-based spinal arrays were generally stable over time up to four weeks after implantation, with a slight increase in impedance in subsequent weeks when tested in spinally injured rats. Taken together, this study demonstrated the potential for carbon-based electrodes as a spinal neural interface to accelerate both mechanistic research and functional restoration in animal models of spinal cord injury.

In situ observation of an atomically modified glassy carbon surface: From synthesis of an Fe-N-C catalyst to intrinsic combined reactions of hydrogen dissociation and the oxygen reduction reaction

We carried out an in situ ambient-pressure X-ray photoemission spectroscopy (AP-XPS) study on the catalytically active surface of glassy carbon subjected to nitrogen-ion implantation and subsequent iron deposition. We also used argon ions to intentionally induce carbon defects on the glassy carbon to compare the effects of substrate defects. Notably, water was produced spontaneously on the modified glassy carbon surface. We compared and clarified the surface structures of the samples in situ by AP-XPS and observed some differences among the pristine glassy carbon (PGC), Fe and N co-doped PGC, Ar-sputtered glassy carbon (AGC), and Fe and N co-doped AGC samples. These differences reveal the potential active site of oxygen reduction reaction and the inherent source for spontaneous dissociation of hydrogen molecules on the atomically modified surface of glassy carbon. The analysis illuminates the new property of glassy carbon itself and offer new direction of Fe-N-C catalyst preparation. • Spontaneous dissociative behavior of hydrogen molecules is possible on Ar sputtered glassy carbon. • Glassy carbon with N 2 sputtering and Fe thermal evaporation have catalytic ability for oxygen reduction. • Using AP-XPS, glassy carbon with treatments is observed in situ.

Ruthenium ion modification of glassy carbon: Implication on the structural evolution and migration behaviour of implanted Ru atoms

Glassy carbon samples were implanted with ruthenium ions to a fluence of 1 × 1016 cm−2 at room temperature (at 150 keV). The implanted samples were annealed isochronally in vacuum from 1000 to 1300 °C for 5 h. The resulting microstructural changes were investigated using X-ray diffraction (XRD), Raman spectroscopy and atomic force microscopy (AFM). The diffusion behaviour of ruthenium in glassy carbon was investigated using secondary-ion mass spectrometry (SIMS). Raman results showed that the implantation of ruthenium into glassy carbon caused amorphization and increase the tensile stress in the implanted region. XRD showed that the amount of tensile stress in virgin glassy carbon increased from 0.016 GPa to 0.19 GPa after ion implantation which is in qualitative agreement with the Raman results. Annealing of the samples exhibited more recrystallization and changed the tensile stress to compressive stress. SIMS results showed that annealing of the as-implanted samples at 1000 °C caused aggregation of the ruthenium atoms, while annealing at higher temperatures led to some segregation of ruthenium atoms at a depth of 155 nm below the glassy carbon surface. The aggregation of ruthenium atoms after annealing (as observed by SIMS) played a role in the surface roughness as observed by AFM.

Fast and Versatile Functionalization of Glassy Carbon

A rapid procedure for the functionalization of glassy carbon surfaces (GCSs) is disclosed. A three-step sequence of bromomethylation, azide displacement, and copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) allows ethynylated molecules to be attached covalently to the carbon surface through a methylene functional group. Redox-active ethynyl ferrocene and [RuII(Cl)(DMSO)(ethynyl-TPA)]1+ (DMSO = dimethylsulfoxide; TPA = tris(2-pyridylmethyl)amine) are attached with high coverages as assessed by cyclic voltammetry, and the elemental composition of the surface is confirmed by X-ray photoelectron spectroscopy. In less than 1 h, surface coverages of 1 × 1014 molecules/cm2 are possible that exhibit good durability in both acidic and basic media. Attached [RuII(Cl)(DMSO)(ethynyl-TPA)]1+ catalytically oxidizes alcohols, yet the currents and potentials are less impressive compared to an attachment without the intervening methylene group. The advantages of this covalent attachment procedure for GCSs are its short reaction times, mild reaction conditions, and the use of standard laboratory reagents and glassware, allowing for many types of ethynylated molecules to be attached rapidly to the surface.

Electrochemical quinuclidine-mediated C–H activation: Intermediates and mechanism

• Hydrogen Peroxide is the terminal oxidant in the reaction. • Quinuclidine is oxidized by hydrogen peroxide to quinuclidine N -oxide. • 1,1,1,3,3,3-hexafluoropropan-2-ol is consumed during oxygen reduction and oxidation to 1,1,1,3,3,3-hexafluoroacetone. • 0.1 M 1,1,1,3,3,3-hexafluoropropan-2-ol is optimal for quinuclidine’s oxidation. The reaction mechanism of quinuclidine mediated C–H oxidation of unactivated C–H bonds has been elucidated. In-situ cathodically generated H 2 O 2 was shown to diffuse to the anode where it is oxidized and participates in the ketonization reaction. Further oxidation of H 2 O 2 to H 2 O, O 2 and H + leads to glassy carbon surface degradation. Oxidation of quinuclidine was shown be kinetic-diffusion control limited and shown to be irreversible at 0 and 1 M 1,1,1,3,3,3-hexafluoroisopropan-2-ol solutions, and quasi-reversible at 0.1 M. Competing side reactions of quinuclidine with hexafluroisopropanol and hydrogen peroxide were identified that lead to decreased reaction efficiency, which explains why quinuclidine needs to be used stoichiometrically.

Acid phosphate-activated glassy carbon electrode for simultaneous detection of cadmium and lead

• Greatly enhanced electron transfer rate was realized by direct electrochemical activation of glassy carbon in acidic PB. • Phosphate anchored on activated glassy carbon was responsible for enrichment of metal ions. • The activated glassy carbon electrode can simultaneously monitor Cd 2+ and Pb 2+ with high sensitivity and low detection limit. • This electrode was featured with easy and fast eco-friendly activation process without adding extra reagents. Lead and cadmium are the most common toxic heavy metals exist in the environment, so it is of significant to develop highly efficient detection methods to monitor lead ions (Pb 2+ ) and cadmium ions (Cd 2+ ). In this work, a simple and eco-friendly electrochemical activation method, for the detection of Pb 2+ and Cd 2+ at trace concentration levels, was successfully utilized to activate the glassy carbon electrode (AGCE), and a great enhancement of the electron transfer ability was achieved. The effect of various activation conditions on electrochemical characteristics of AGCE and on the simultaneous current responses to Cd 2+ and Pb 2+ were investigated. Field emission scanning electron microscopy characterization revealed that phosphate was anchored on the activated glassy carbon surface. At the optimal condition, the AGCE could dual detect Cd 2+ and Pb 2+ with lowest detection limits of 17 and 0.3 nM, and linear concentration ranges of both in 0.05–5 µM. Furthermore, satisfactory recoveries in the analysis of real water samples were achieved, indicating the promising applicability of AGGE for real water monitoring.

Co-electrodeposited PtPd anodic catalyst for the direct formic acid fuel cells

This investigation displayed a superb catalytic performance toward the formic acid electro-oxidation reaction (FAOR) in an alkaline medium at a binary catalyst composed of Pt and Pd that were simultaneously electrodeposited onto a glassy carbon (GC) surface. Interestingly, the proposed PtPd/GC catalyst displayed a significant enhancement in the catalytic activity (by ca. 12 times higher direct (Ipd) to indirect (Ipind) current ratio concurrently with ca. -91 mV shift in the onset potential (Eonset) and stability (ca. 2.5 times higher current density after 3600 s of continuous electrolysis) toward FAOR if compared to the Pt/GC catalyst. The catalytic enhancement was thought to arise mostly from minimizing the CO adsorption, i.e., third body effect, at the Pt surface during FAOR.

(Digital Presentation) Electrochemical Analysis of Oxygen Reduction in Phosphonium Ionic Liquids Based on Rotating Ring-Disk Electrode Method

Ionic liquids (ILs) have characteristic physicochemical properties such as high thermal stability, low volatility, low melting point, and flame resistance. Moreover, ILs exhibit also excellent electrochemical properties represented by a wide potential window.[1] Hence, they have a great potential for electrochemical applications such as electrolytes for batteries, capacitors, fuel-cells and so on. Phosphonium ILs have unique physical characters such as lower viscosity and higher ionic conductivity compared with corresponding structured ammonium ILs.[2] Recently, we have evaluated the diffusion coefficient and the solubility of oxygen molecules in phosphonium ILs and have clarified that such oxygen behaviors strongly depends on the chemical structure of cation rather than that of anions. In the present study, we demonstrated the proton effect for the ORR in phosphonium ILs using rotating ring disk electrode (RRDE) technique.[3] Tetraalkyl-phosphonium(PXXXY+ and bis(trifluoromethane sulfone) imide (TFSA-)) ILs were used for electrolytes.Cyclic voltammetry (CV) and convective voltammogram were performed using a three electrode cell at 25oC. The RRDE constructed a glassy carbon (GC) or platinum (Pt) disk, and Pt ring electrodes were used as the working electrodes. The ring current was measured at a potential of 1.0 V vs. Ag/Ag+ reference electrode, where the intermediate oxidation reaction enough attached to diffusion limit.In the non-protonic media, ORR currents were observed from –0.6 V on GC disk electrode and –0.5 V on Pt disk electrode respectively, which were corresponding to the one-electron reduction reaction in ORR. On the other hand, the on-set potential of ORR in protonic media was higher than that in non-protonic media on both electrodes. Such potential shifts were strongly appeared on the Pt disk electrode than that on the GC disk electrode. Moreover, the diffusion limiting current was observed on Pt disk electrode at higher potential region in protonic media, and the current increased with increasing H-TFSA content. Therefore, the limiting current originated from not the transport of oxygen molecules, but that of proton, while the ring current oppositely decreased with increasing H-TFSA content. The ring current originated from intermediate formed on Pt disk electrode was smaller than that on GC disk electrode. These results indicated that the number of electrons in ORR increased by the existence of proton, and the effect of proton was promoted on Pt surface better than the GC surface.[1] A. Khan, C. Zhao, ACS sustainable Chem. Eng. 4, 506 (2016)[2] K. Tsunashima, and M. Sugiya, Electrochemistry Communications, 9, 2353- 2358(2007)[3] M. Hildera, et al, Electrochimica Acta, 202, 100-109(2016).

Preparation, optical and electrochemical properties of unsymmetrical tetrazaporphyrins with a diarylchalcogenophene unit

Unsymmetrically substituted tetraazaporphyrins, dithienylthienotris(dialkyloxybenzo)tetraazaporphyrins (alkyl = butyl and octyl), were prepared by the reaction of 2,5-dithienyl-3,4-dicyanothiophene with 2,5-di(alkyloxy)phthalonitriles in the presence of lithium alkoxide. Similar reactions of 3,4-dicyanothiophene, 2,5-diphenyl-3,4-dicyanothiophene, and 2,5-diphenyl-3,4-dicyanoselenophene with 2,5-di(octyloxy)phthalonitrile gave thieno, diphenylthieno, and diphenylselenolotris(dioctyloxybenzo)tetraazaporphyrins, respectively. The structures of the products were determined by 1H NMR spectroscopy and high-resolution FAB MS spectrometry. Optical and electrochemical properties of the products were determined by UV–vis spectroscopy and cyclic voltammetry using Ag/AgNO3 as a reference electrode (solvent: dichloromethane; counter electrode: Pt; electrolyte: n-Bu4NClO4). An insoluble thin film was produced on the glassy carbon and ITO electrode surfaces by the electrochemical oxidation of dithienylthienotris(dibutoxybenzo)tetraazaporphyrin. The optical and electrochemical properties of the film were determined by UV–vis spectroscopy and cyclic voltammetry. The structures of simplified model compounds were optimized using the DFT method with the Gaussian 09 program at the B3LYP/6-31G(d,p) level.

Revealing the Heterogeneity of Large-Area MoS2 Layers in the Electrocatalytic Hydrogen Evolution Reaction.

The electrocatalytic activity concerning the hydrogen evolution reaction (HER) of micrometer‐sized MoS2 layers transferred on a glassy carbon surface was evaluated by scanning electrochemical cell microscopy (SECCM) in a high‐throughput approach. Multiple areas on single or multiple MoS2 layers were assessed using a hopping mode nanocapillary positioning with a hopping distance of 500 nm and a nanopipette size of around 55 nm. The locally recorded linear sweep voltammograms revealed a high lateral heterogeneity over the MoS2 sheet regarding their HER activity, with currents between −40 and −60 pA recorded at −0.89 V vs. reversible hygrogen electrode over about 4400 different measured areas on the MoS2 sheet. Stacked MoS2 layers did not show different electrocatalytic activity than the single MoS2 sheet, suggesting that the interlayer resistance influences the electrocatalytic activity less than the resistances induced by possible polymer residues or water layers formed between the transferred MoS2 sheet and the glassy carbon electrode.

Taurine Electrografting onto Porous Electrodes Improves Redox Flow Battery Performance

The surface properties of porous carbonaceous electrodes govern the performance, durability, and ultimately the cost of redox flow batteries (RFBs). State-of-the-art carbon fiber-based electrode interfaces suffer from limited kinetic activity and incomplete wettability, fundamentally limiting the performance. Surface treatments for electrodes such as thermal and acid activation are a common practice to make them more suitable for aqueous RFBs; however, these treatments offer limited control over the desired functional properties. Here, we propose, for the first time, electrografting as a facile, rapid, and versatile technique to enable task-specific functionalization of porous carbonaceous electrodes for use in RFBs. Electrografting allows covalent attachment of organic molecules on conductive substrates upon application of an electrochemical driving force, and the vast library of available organic molecules can unlock a broad range of desired functional properties. To showcase the potential of electrografting for RFBs, we elect to investigate taurine, an amine with a highly hydrophilic sulfonic acid tail. Oxidative electrografting with cyclic voltammetry allows covalent attachment of taurine through the amine group to the fiber surface, resulting in taurine-functionalized carbon cloth electrodes. In situ polarization and impedance spectroscopy in single-electrolyte flow cells reveal that taurine-treated cloth electrodes result in 40% lower charge transfer and 25% lower mass transfer resistances than off-the-shelf cloth electrodes. We find that taurine-treated electrode interfaces promote faster Fe3+ reduction reaction kinetics as the electrochemical surface area normalized current densities are 2-fold and 4-fold higher than oxidized and untreated glassy carbon surfaces, respectively. Improved mass transfer of taurine-treated electrodes is attributed to their superior wettability, as revealed by operando neutron radiography within a flow cell setup. Through demonstrating promising results for aqueous systems with the model molecule taurine, this work aims to bring forth electrografting as a facile technique to tailor electrode surfaces for other RFB chemistries and electrochemical technologies.

Spontaneous Decarboxylation of Ferrocenecarboxylate using 1,4‐Benzoquinone as Oxidant: Application to the Chemical Grafting of Glassy Carbon Surfaces

AbstractThe covalent modification of glassy carbon electrode with ferrocenyl moieties was performed in acetonitrile using a mixture of ferrocenecarboxylate (FcCOO−) and ferrocenecarboxylic acid (FcCOOH). This process is activated by 1,4‐benzoquinone (Q), which plays the role of oxidant. The carboxylate induces the redox reduction of the quinone whereas an excess of the carboxylic acid drives the protonation of the reduced quinone to yield hydroquinone (QH2) as a reaction product. Due to the homogeneous oxidation of the carboxylate derivative, carbon dioxide and ferrocenyl radicals (Fc⋅) are released, such as occurs in the classical Kolbe reaction. The generation of ferrocenyl radicals allows the chemical derivatization of non‐connected glassy carbon surfaces. The homogeneous redox reaction between the 1,4‐benzoquinone and ferrocenecarboxylate proceeded slowly and permitted the covalent attachment of a thin film with ferrocenyl moieties, whose presence on the carbon surface was evidenced from cyclic voltammetry and atomic force microscopy (AFM) measurements.

Sensitive Electrochemical Detection of Thiabendazole in Fruits Using Ag−MoS2 Electrode

AbstractHerein, Ag nanoparticles (NPs) modified MoS2 (Ag−MoS2) was applied to the surface of glassy carbon (GC) to produce a robust electrochemical sensor for the detection of thiabendazole, a common antifungal in the post‐harvesting of fruits. Cyclic voltammetry studies confirmed thiabendazole exhibited an irreversible, diffusion‐controlled process on Ag−MoS2 with a two‐fold increase in peak current than the pristine MoS2. A square wave voltammetry was used for the detection of TBZ. The developed sensor exhibited a linear range between 1–10 μM with LOD down to 0.1 μM (S/N>3). Analysis of TBZ in mango and banana matrices gave a recovery of 91.6–100.4 % indicating the suitability of the sensor for food safety monitoring.

Poly(Thiophene)/Graphene Oxide-Modified Electrodes for Amperometric Glucose Biosensing.

The availability of fast and non-expensive analytical methods for the determination of widespread interest analytes such as glucose is an object of large relevance; this is so not only in the field of analytical chemistry, but also in medicinal and in food chemistry. In this context, electrochemical biosensors have been proposed in different arrangements, according to the mode of electron transfer between the bioreceptor and the electrode. An efficient immobilization of an enzyme on the electrode surface is essential to assure satisfactory analytical performances of the biosensor in terms of sensitivity, limit of detection, selectivity, and linear range of employment. Here, we report the use of a thiophene monomer, (2,5-di(2-thienyl)thieno [3,2-b]thiophene (dTT-bT), as a precursor of an electrogenerated conducting film to immobilize the glucose oxidase (GOx) enzyme on Pt, glassy carbon (GC), and Au electrode surfaces. In addition, the polymer film electrochemically synthetized on a glassy carbon electrode was modified with graphene oxide before the deposition of GOx; the analytical performances of both the arrangements (without and with graphene oxide) in the glucose detection were compared. The biosensor containing graphene oxide showed satisfactory values of linear dynamic range (1.0–10 mM), limit of detection (0.036 mM), and sensitivity (9.4 µA mM−1 cm−2). Finally, it was tested in the determination of glucose in fruit juices; the interference from fructose, saccharose, and ascorbic acid was evaluated.

Nanostructured Cyclodextrin-Mediated Surface for Capacitive Determination of Cortisol in Multiple Biofluids.

The aim of this work is to develop a reusable polypropylene glycol (PPG):β-cyclodextrin (βCD) biosensor for cortisol detection. To achieve the most stable support for βCD, we developed two PPG surfaces. The first surface is based on a gold surface modified with SAM of 3-mercaptopropionic acid (3MPA), and the second surface is based on a glassy carbon surface grafted with 4-carboxyphenyl diazonium salt. We characterized both surfaces by EIS, XPS, and ATR-FTIR and evaluated the stability and reusability of each surface. We found the GC-carboxyphenyl-PPG:βCD is stable for at least 1 month. We have also demonstrated the reusability of the surface up to 10 times. In detecting cortisol, we used a nonfaradaic electrochemical impedance capacitive model to interpret the surface confirmation changes. We achieved sensitive detection of cortisol in PBS buffer, urine, and saliva with limit of detection of 2.13, 1.29, and 1.33 nM, respectively.

Experimental determination of the spectral absorption coefficient of a plasma-erosion torch on the surface of carbon-bearing materials

In the work, the spectral coefficient of the plasma-erosion torch on the glassy carbon surface was determined on the basis of the Wien violation law and the experimental determination of the brightness temperature. The possibility of using a micropyrometer to determine the spectral factor can be a plasma-erosion torch, with the help of which (spectral absorption coefficient) it is rather quick to determine the thermodynamic temperature of the plasma-erosion torch.

Surface engineering of Pt surfaces with Au and cobalt oxide nanostructures for enhanced formic acid electro-oxidation

A novel n-CoOx/n-Au/n-Pt nanocatalyst assembled onto a glassy carbon (GC) substrate is recommended for efficient formic acid electro-oxidation (FAEO), the principal anodic reaction in the direct formic acid fuel cells (DFAFCs). • A catalyst composed of Pt nanoparticles was engineered with Au and cobalt oxide nanostructures. • It showed a promising catalytic performance toward the formic acid electro-oxidation. • Adjusting its loading hierarchy drove the reaction mechanism to the desirable dehydrogenation pathway. • Geometric and electronic enhancements were elucidated and quantified. This study aims to mitigate the CO poisoning of platinum (Pt) surfaces during formic acid electro-oxidation (FAEO), the essential anodic reaction in the direct formic acid fuel cells (DFAFCs). For this purpose, a glassy carbon (GC) electrode was amended sequentially with Pt (n-Pt), gold (n-Au), and cobalt oxide (n-CoOx) nanostructures. Fascinatingly, the ternary modified n-CoOx/n-Au/n-Pt/GC catalyst (for which n-Pt, n-Au, and n-CoOx were sequentially and respectively assembled onto the GC surface) exhibited a remarkable electrocatalytic enhancement toward FAEO, which surpassed ca. 53 times that of the Pt/GC catalyst. Additionally, it exhibited a much (ca. 18 times) higher stability after 3000 s of continuous electrolysis. The observed enhancement was proven to originate from driving the reaction mechanism principally to the desirable direct dehydrogenation pathway on the expense of the poisoning dehydration path. The impedance and CO stripping measurements confirmed the prevailing of both the electronic and third body effects in the catalytic enhancement.