Fabrication of a bimetallic Cu/Pt particle-modified carbon nanotube paste electrode and its use for the electrocatalytic oxidation of methanol

In this work, carbon nanotube paste electrode (CNTPE) was used as a substrate for deposition of bimetallic Cu/Pt particles. At first, a Cu film was prepared by electrochemical reduction of Cu ions onto the CNTPE in 0.1 M H₂SO₄ solution. Cu/Pt catalysts were prepared by partial galvanic replacement of Cu with Pt by simply immersion of the Cu-coated CNTPE in 2.0 mM H₂PtCl₆ solution. The nature and surface morphology of the bare CNTPE and fabricated Cu/Pt species were characterized by scanning electron microscopy and energy dispersive X-ray spectrometry. The Cu/Pt-modified CNTPE exhibits remarkable electrocatalytic activity towards methanol oxidation. It has been shown that carbon nanotubes improve the electrocatalytic activity of the catalysts towards oxidation. Then, the influence of various parameters such as Cu source concentration, electrodeposition time, replacement time, and methanol concentration on its oxidation as well as long-term stability of the modified electrode have been investigated by electrochemical methods.     

Tuning concave PtSn nanocubes for efficient ethylene glycol and glycerol electrocatalysis

Shape-controlled synthesis of well-defined nanostructures offers a great opportunity to promote electrocatalytic performances while reducing the mass loading of noble metals. Herein, we show how morphology can effectively affect the electrocatalytic properties of nanocrystals for alcohol electrooxidation reaction, a key barrier to the application of fuel cells. We report the synthesis of a new generation of alloyed PtSn concave nanocubes (CNCs) through a facile one-pot wet-chemical method. Owing to strong synergistic effect between Pt and Sn, modified electronic structure, as well as high surface areas, the as-obtained alloyed PtSn CNCs can display outstanding electrocatalytic performances for liquid fuel electrooxidation. Impressively, the optimized Pt₄Sn₁ concave nanocubes (CNCs) can achieve a factor of 5.1 enhancements in mass activity and a factor of 5.9 enhancements in specific activity towards ethylene glycol oxidation (EGOR) in comparison with commercial Pt/C catalysts. Moreover, 4.6 and 5.3-fold enhancements in mass and specific activity were also acquired for glycerol oxidation reaction (GOR) compared to those of the commercial Pt/C, holding great promise for future application in fuel cells.     

Amorphous NiB alloy decorated by Cu as the anode catalyst for a direct borohydride fuel cell

In this study, amorphous NiB alloy decorated by Cu is prepared by chemical reduction. Moreover, the effect of Cu addition for the electrocatalytic activity of borohydride (BH₄⁻) oxidation is studied. The physical characteristics of NiB or NiBCu_x nanoparticles are confirmed by transmission X-ray diffraction (XRD) and scanning electron microscopy (SEM). The physical characterization results demonstrate that the NiB or NiBCu_x nanoparticles have an amorphous structure and NiBCu_x nanoparticles have improved dispersity. The borohydride oxidation activity of the as-prepared catalysts is investigated by cyclic voltammetry (CV), linear scan voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). Results indicate that the NiBCu_x/C nanoparticles have higher electrocatalytic activity for borohydride oxidation than NiB/C, and the borohydride oxidation current of NiBCu_x/C nanoparticles initially increases and then decreases with the increase in Cu content. The optimum molar content of copper in the six prepared catalysts is 2.2%. It is proposed that the addition of Cu is conducive to sodium borohydride adsorption, thereby improving the electro-oxidation activity for borohydride. Hence, amorphous NiB alloy decorated by Cu can enhance the electro-oxidation performance for borohydride.     

Trimetallic PdCuIr nanocages as efficient bifunctional electrocatalysts for polyalcohol oxidation and hydrogen evolution reaction

Despite amounts of researches in recent years, it is still desirable but challenging to fabricate well-defined bifunctional catalysts with high performance towards alcohol oxidation and hydrogen evolution reaction (HER). Herein, a unique trimetallic PdCuIr catalyst with a nanocage (NC) structure is synthesized to be an excellent bifunctional catalyst by a seed-mediated growth strategy. The as-prepared PdCuIr NC catalyst exhibits remarkably enhanced mass activity and durability towards glycerol oxidation reaction (GOR) and ethylene glycol oxidation reaction (EGOR) as compared with commercial Pd/C catalyst. The optimal Pd₅₈Cu₃₂Ir₁₀ NCs show electrocatalytic activities of 2565.79 mA mg_Pd⁻¹ and 4498.30 mA mg_Pd⁻¹ for GOR and EGOR, respectively. Meanwhile, the well-defined PdCuIr NC catalyst also displays outstanding electrocatalytic performance for HER, and the overpotential of Pd₅₈Cu₃₂Ir₁₀ NCs only requires 54 mV to arrive at a current density of 10 mA cm⁻², along with excellent electrochemical durability. The enhancement of electrocatalytic properties is attributed to the introduction of Cu and Ir atoms, which could modify the electronic structure of Pd to optimize the adsorption of reactants and intermediates. Moreover, the unique NC structure also significantly increases the number of reaction active sites as well as accelerates mass transport. Following this method, the trimetallic PdCuRu NCs and PdCuRh NCs are also synthesized. This work not only offers a general strategy for the fabrication of well-defined ternary alloy nanocatalysts, but also presents an advanced class of bifunctional catalysts for polyalcohol electrooxidation and HER.     

Preparation and characterization of copper oxide particles/polypyrrole (Cu2O/PPy) via electrochemical method: Application in direct ethanol fuel cell

The electrocatalytic performance of Polypyrrole-Copper oxide particles modified carbon paste electrode (Cu₂O/PPy/CPE) for electrocatalytic oxidation of ethanol was reported for the first time in alkaline media. The composite Cu₂O/PPy was prepared using a facile approach consisting on the deposition of Polypyrrole film on CPE using galvanostatic mode then followed by the deposition of Copper particles at a constant potential. Scanning electron spectroscopy (SEM), infrared spectroscopy (FTIR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were employed to characterize the structural and electrochemical properties of the Cu₂O/PPy/CPE and to explain the mechanism of electrooxidation of ethanol. The experimental parameters that influence the electrooxidation of ethanol were investigated and optimized. Our findings suggest that the electrodeposition of Copper particles on Polypyrrole film enhanced the catalytic activity towards the ethanol oxidation with a peak current density of 2.25 mA cm⁻² at 0.8 V vs Ag/AgCl, which is 2.6 times higher than the peak current density obtained by PPy/CPE electrode. It important to note that the saturation limit reaches a value of 5 M. To summarize, the good catalytic activity, stability and easy preparation make the Cu₂O/PPy composite as an excellent electrocatalyst for ethanol oxidation.     

Effect of the structure of Ni nanoparticles on the electrocatalytic activity of Ni@Pd/C for formic acid oxidation

Ni@Pd/C catalysts were synthesized, using Ni/C with different crystalline structures prepared with various ligands. A series of characterizations were performed by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy. The results indicated the electrocatalysts with amorphous/crystalline (denoted as Ni_a and Ni_c) Ni structures decorated with Pd. The formic acid electrocatalytic oxidation results showed that the peak current of Ni_a@Pd/C was about 1.2 times higher than that of Ni_c@Pd/C. The good electrochemical performance and stability of Pd-modified amorphous Ni substrate reveals that the core structure plays an important role in the electrocatalytic activity and the change of the structure can improve the activity and stability of electrocatalysts.     

Electrocatalysis by design: Enhanced electro-oxidation of glycerol at NiOx nanoparticle modified 3D porous carbon felts

This paper addresses the preparation of three-dimensional functionalized carbon felts (CFs), which were coated with nickel (Ni) nanostructures and used as an electrocatalyst for glycerol electrooxidation in alkaline medium. The commercial CFs (3D-carbon fibers) were first functionalized with O- and S- like functionalities via electrochemical pretreatment in NaOH and H₂SO₄, then the impacts of this pretreatment on the electrodeposited Ni nanoparticles (NiNPs) morphology, distribution, structure and performance for glycerol electrooxidation was investigated. X-ray diffraction (XRD) together with cyclic voltammetry (CV) techniques were used to detect the changes of the electrodeposited Ni oxide phases. Contact angle was used to determine impact of pretreatment on the wettability of CF. X-ray photoelectron spectroscopy (XPS) was used to get information about the added functional groups while scanning electron microscope (SEM) was used to observe the changes of NiNPs morphology, distribution, and particle size. As-synthesized NiNPs modified functionalized CFs exhibited an excellent activity concurrent with good stability for glycerol electrooxidation. The pretreatment of CF in either NaOH or H₂SO₄ resulted in a significant increase in the Ni surface active sites and improved their electrocatalytic activity for glycerol electrooxidation.     

Efficient photocatalytic hydrogen production by doped ZnS grown on Ni foam as porous immobilized photocatalysts

Ni-doped ZnS nanomaterials were decorated on the surfaces of porous Ni foam as immobilized photocatalysts for H₂ production by a solvothermal process. Effects of the Ni dopant content on the photocatalytic hydrogen production activity, morphology, optical property, crystalline properties, surface wetting, and photocurrent were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), photoluminescence (PL), photocurrent response, and contact angle meter. The surface changed from hydrophobic to superhydrophilic by decorating Ni-doped ZnS on the NiO/Ni foam substrate. A mechanism is proposed to elucidate the band positions of ZnS and NiO, together with the transfer of photoinduced electrons among ZnS, NiO, and Ni foam. The Ni-doped ZnS/NiO/Ni foam photocatalyst NZ5 showed much higher photocatalytic activity because of the matched band structure and the high conductivity of Ni foam. Meanwhile, the porous texture and superhydrophilic nature of the photocatalyst favor the light trapping, effective mass transfer of reactant molecules, and provide large contact area. Ni doping leads to a decreased band gap. The highest photocatalytic H₂ generation activity reached 2500 μmol/g⁻¹ h⁻¹. After being operated for 3 cycles, the activity of the third run was 85% of that obtained at the first run.     

Electrodeposited Pd nanoparticles on polypyrole/nickel foam for efficient methanol oxidation

The present work describes the Ni foam (Ni–F)/polypyrrole (PPy)/palladium (Pd) (Ni–F/PPy/Pd) multilayered catalysts via a facile electrochemical technique. Potentiostatic deposition of PPy on the surface of Ni–F is followed by galvanostatic deposition of Pd nanoparticles on Ni–F/PPy acted as supports for electrochemical deposition of Pd nanoparticles. The produced catalysts are utilized for electrocatalytic methanol oxidation in alkaline media. Chronoamperometry (CA), cyclic voltammetry (CVs), and electrochemical impedance spectroscopy (EIS) techniques are used to examine the electrocatalytic performance of Ni–F/PPy/Pd based electrodes for methanol oxidation. The polypyrrole modification on Ni–F leads to an improvement in the electrocatalytic activity of the Ni-F/PPY-Pd catalysts toward methanol oxidation. As an open-pored, porous metal with high electrical conductivity, nickel foam produces a substantial amount of active area during the modification of Pd and polypyrrole, which results in significant catalytic activity and a rapid rate charge transfer reaction kinetics on methanol oxidation. The Ni–F/PPy/Pd10 catalyst exhibits enhanced specific activity than its counterparts and a reduced onset potential for methanol oxidation, as well as a low Tafel slope. Based on these results, Ni–F/PPy/Pd10 is suggested as a good material for the anode in the electrocatalytic oxidation of methanol.     

Modification of palladium surfaces by bismuth adatoms or clusters: Effect on electrochemical activity and selectivity towards polyol electrooxidation

The syntheses of Bi-modified Pd catalysts with a controlled size distribution are presented as well as the characterizations of their structures and of their surfaces. Effects of the modification either of non-supported Pd nanospheres by spontaneous deposition of Bi or of carbon-supported Pd-based nanomaterials by decoration with bismuth clusters on the electrocatalytic activity towards glycerol electrooxidation were evaluated and compared in alkaline medium. The method of bismuth deposition has a dramatic effect on the activity of the palladium based catalysts: spontaneous deposition of Bi on non-supported Pd nanoparticles leads to relatively low activity enhancement, whereas decoration of carbon-supported Pd nanoparticles by Bi₂O₃ and Bi(OH)₃ clusters leads to very high activity increase at low overpotentials. In situ infrared spectroscopy indicated that the modification of Pd by Bi did not affect the selectivity of glycerol oxidation, whereas in the case of Pt containing catalyst, a dramatic change in selectivity occurred at low potentials.     

Electrodeposited Ni–Pt binary alloys as electrocatalysts for oxidation of ammonia

Electrocatalytic activity of Ni–Pt binary alloy electrodes fabricated by electrolytic deposition for oxidation of ammonia was investigated by cyclic voltammetry and surface analysis techniques. The parametric effects, including ammonia concentration, KOH concentration and temperature, on ammonia electro-oxidation on Ni–Pt electrode were investigated. It is found that electrocatalytic activity of the fabricated Ni–Pt electrode with only 1 mg cm⁻² of Pt loading for ammonia oxidation is comparable to that of pure Pt electrode. With the increases in Pt loading concentration on Ni surface, the catalytic activity for ammonia oxidation further increases. Electro-oxidation of ammonia is rate-limited by diffusion of NH₃ towards the electrode surface. The NH₃ adsorption then occurs at the active spots that are associated with the deposited Pt on Ni surface. With the increase of Pt loading concentration, the Pt distribution is more uniform and the size of Pt particles becomes smaller within the range of nano-scale, resulting in the significant increase of total active area for NH₃ adsorption and further oxidation. It is demonstrated that fabrication by electrolytic deposition of Ni–Pt binary alloy electrode provides a promising alternative for development of low-cost, high-performance electrocatalyst for electro-oxidation of ammonia.     

Carbon nanofibers decorated SiC foam monoliths as the support of anti-sintering Ni catalyst for methane dry reforming

A silicon carbide (SiC) foam monolith decorated with a carbon nanofibers (CNFs) layer was employed as the catalyst support for Ni-based catalyst preparation, used for the CO₂ dry reforming of methane (DRM) reaction. The loading amount of CNFs on the SiC foam monolith was 6.6 wt.%, which obviously increased the surface area of the pristine SiC foam from 4 m²/g to 24 m²/g. The prepared CNFs layer strongly attached to the pristine SiC surface and was considerably stable even after 100 h time on stream (TOS) DRM reaction. The CNFs decorated SiC composite support provided more anchorage sites for improving the dispersion of the Ni particles and enhanced the metal-support interaction compared to the pristine SiC support. Compared with other catalysts such as Ni/SiC and Ni/CNFs, the Ni/CNFs-SiC catalyst exhibited not only the highest activity but also remarkable stability during DRM reaction. The XPS and SEM-EDS results showed that the carbon deposition over the nickel surface of Ni/CNFs-SiC catalyst was much less than those of Ni/SiC and Ni/CNFs catalysts. In addition, the XRD analysis verified that almost no sintering of nickel particle was detected over the Ni/CNFs-SiC catalyst, which was prepared with CNFs-SiC composite as catalyst support, even after 100 h TOS DRM reaction at 750 °C.     

Electrochemical preparation and characterization of Pt particles on ITO substrate: Morphological effect on ammonia oxidation

Pt particles with different surface morphology (spherical, flower-like or sheet-like) were successfully deposited on the ITO substrate by controlling the deposition current density using the electrochemical deposition method. The prepared Pt/ITO electrodes were characterized by scanning electron microscopy, inductively coupled plasma, X-ray diffraction and cyclic voltammetry. The results showed that the fabricated Pt/ITO electrode can be successfully used for the electro-oxidation of ammonia. Furthermore, the surface morphology of the Pt particles on the ITO substrates has a significant influence on the electrocatalytic activity for ammonia oxidation. The flower-like and sheet-like Pt particles have a much higher electrocatalytic activity for ammonia oxidation than the smooth spherical Pt particles. The high electrocatalytic activity of the former is not only due to their larger electrochemical active surface area, but also due to their special morphology. There are many tips or edges on the surface of the flower-like or sheet-like Pt particles which may contribute to their high electrocatalytic activity per unit electroactive surface area, as confirmed by the electrochemical tests.     

A novel co-electrodeposited Co/MoSe2/reduced graphene oxide nanocomposite as electrocatalyst for hydrogen evolution

In this study, a simple and fast electrochemical method was employed to synthesis molybdenum diselenide thin film. The morphology, structure and chemical composition of the nanocomposites were investigated by field emission scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The progressive effects of transition metal ions including Ni, Cu, and Co were surveyed on the hydrogen evolution activity of MoSe₂ thin films. Co/MoSe₂ nanocomposite thin films has significant electrocatalytic activity as compared to other samples, In order to achieve higher performance, preparing Co/MoSe₂/RGO nanocomposite thin film, two strategies including layer by layer electrodeposition and co-electrodeposition has been employed. The presence of reduced graphene oxide leading to the onset potential shifts to more positive values and increase the current density. Also, results showed that the Co/MoSe₂/RGO nanocomposite prepared by co-electrodeposition exhibits the best electrochemical hydrogen evolution at onset potential of −0.18 with an overpotential of −0.45 V.     

Electrodeposited Ni on pencil graphite electrode for glycerol electrooxidation in alkaline media

In this study, we report the electrocatalytic oxidation of glycerol in alkaline solution onto Ni modified pencil graphite electrodes (Ni/PGEs). Field-emission gun scanning electron microscopy (FEG-SEM) and energy-dispersive X-ray spectroscopy (EDX), as well as cyclic voltammetry (CV) have been used for the clarification of the physicochemical and electrochemical properties of Ni/PGEs. The electrocatalytic performance of Ni/PGEs towards glycerol electrooxidation was investigated using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). Ni/PGE elaborated at pH = 6.92 showed the best performance for glycerol electrooxidation reaction in alkaline media. The direct comparison of glycerol, methanol, and ethanol electrooxidation revealed that glycerol is better than ethanol at 35 and 45 °C with a lower onset potentials and higher current densities. Ni/PGE characteristics surpass other nickel based electrodes and therefore promote its use as glycerol electrocatalyst.     

Comparison of electrocatalytic activity of carbon-supported Au–M (M = Fe,Co, Ni,Cu and Zn) bimetallic nanoparticles for direct borohydride fuel cells

The Au–M (M = Fe, Co, Ni, Cu and Zn) bimetallic nanoparticles supported on the Vulcan XC-72R (Au–M/C) were synthesized by a reverse micelle method. The structures and compositions of the carbon supported Au–M catalysts were characterized by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDS). The electrocatalytic activity of the Au–M bimetallic nanoparticles with respect to borohydride electro-oxidation for the application of fuel cell was investigated by voltammetry, chronoamperometry and chronopotentiometry. The results showed that alloying Au with 3d transition metals Fe, Co, Ni, Cu or Zn, a metal that leads to the maximum eight-electron oxidation of BH₄⁻, not only improved the electrode kinetics of BH₄⁻ oxidation but also reduced catalyst cost. Among the various investigated Au–M/C electrocatalysts, the Au–Zn, Au–Fe and Au–Cu catalysts showed no activity of NaBH₄ hydrolysis, and Au–Zn presented an attractive catalytic activity for borohydride oxidation.     

Enhanced electrocatalytic activity of nickel particles electrodeposited onto poly (m-toluidine) film prepared in presence of CTAB surfactant on carbon paste electrode for formaldehyde oxidation in alkaline medium

In this work, carbon paste electrode is coated with poly (m-toluidine) film by potentiodynamic electropolymerization of m-toluidine monomer in the presence of cetyltrimethyl ammonium bromide (CTAB-PMT/MCPE). Then electrolysis at fixed potential (−1.0 V versus reference electrode for 15 min) is employed for electrodepositing of Ni from 1.5 M NiSO₄ acidic solution at the surface of polymer-modified electrode for preparation of Ni/CTAB-PMT/MCPE. The general electrochemical behaviors of these modified electrodes are characterized by cyclic voltammetry in alkaline media. In alkaline medium (i.e. NaOH 0.1 M) a good redox behavior of Ni(III)/Ni(II) couple at the surface of these electrodes can be observed. The nickel particles electrodeposited at the surface of Ni/CTAB-PMT/MCPE exhibits a significant electrocatalytic activity towards oxidation of formaldehyde. Moreover, the effects of various parameters such as concentration of CTAB, concentration of formaldehyde, film thickness and monomer concentration on the electrooxidation of formaldehyde as well as long-term stability of the Ni/CTAB-PMT/MCPE have also been investigated.     

Mechanism of glycerol oxidation reaction on silver-modified palladium electrode in alkaline medium

The silver-modified Pd (Ag/Pd) electrode was prepared by underpotential deposition of Cu adatoms, followed by galvanic displacement with Ag atoms to investigate the effect of silver modification on the catalysis and mechanism for glycerol oxidation reaction (GOR) of Pd. Cyclic voltammograms in alkaline glycerol solution exhibited that the Ag/Pd electrode had ca. 100 mV less positive onset potential of the GOR current density and higher peak current density than the Pd electrode, indicating that the GOR activity of Pd was enhanced by surface modification with Ag atoms. In potentiostatic electrolysis at ?0.1 V vs. Hg/HgO, GOR mainly began with the oxidation of a terminal OH group for both electrodes, and glycerate and glycolate were major products. The glycolate production was more active for the Ag/Pd electrode. The in situ infrared reflectance-absorption spectra (IRAS) exhibited that GOR products with one or two carbons were detected at lower potentials for the Ag/Pd electrode, indicating that the CC bond cleavage was facilitated by the Ag modification.     

Electrooxidation of ethanol and glycerol on carbon supported PtCu nanoparticles

Four carbon supported PtCu nanostructured catalysts with Pt:Cu atomic ratios of 1:3.20, 1:2.23, 1:0.61 and 1:0.35 were synthesized by a two-step route, involving the chemical reduction of Cu ions on the carbon support, followed by the partial galvanic replacement of Cu atoms by Pt. Bimetallic nanostructured particles with average sizes in the range of 2.3–3.2 nm were obtained. The bimetallic catalysts with surface Pt contents between 20 and 55 at. % were formed by a Cu-rich core surrounded by a Pt-Cu shell, while that with the highest Pt content presented a uniform alloy structure instead of a core-shell arrangement. The electrocatalytic performance of the as-prepared materials toward ethanol electrooxidation in acid and alkaline media and glycerol oxidation in alkaline environment was investigated by cyclic voltammetry and chronoamperometry. It was observed that the electrocatalytic activity of PtCu nanoparticles was found to depend on the surface composition, platinum utilization efficiency, structure and Pt ensemble. Among the as-prepared catalysts, Pt_0·62Cu_0·38/C core-shell material showed the best performance for ethanol oxidation in both acid and alkaline environments, while Pt_0·24Cu_0·76/C and Pt_0·31Cu_0·69/C core-shell catalysts exhibited the highest activity for glycerol oxidation in alkaline medium. The electrochemical results showed that the catalytic activity of the bimetallic Cu@PtCu core-shell nanostructured nanoparticles is between four and ten times higher than that of a commercial Pt_0·51Ru_0·49/C catalyst.     

Enhanced electrocatalytic activity of NiO nanoparticles supported on graphite planes towards urea electro-oxidation in NaOH solution

Nickel oxide nanoparticles are fabricated onto graphite planes [NiO/Gt] by chemical precipitation of Ni(OH)₂ particles with consecutive calcination at 400 °C. The formed electrocatalysts are characterized using X-ray diffraction (XRD) and Transmission electron microscopy (TEM). TEM images demonstrate the deposition of NiO nanoparticles on graphite surface through their crystallite lattice fringes with spacing values of 2.45 Å (111), 2.10 Å (200) and 1.48 Å (220). The electrocatalytic activity of NiO/Gt electrocatalyst is examined towards urea electro-oxidation in NaOH solution using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. Urea oxidation peak current density is observed at NiO/Gt electrocatalyst containing 15 wt% NiO [NiO/Gt?15] at a potential value of +640 mV (Ag/AgCl) with a current density value of 17.63 mA cm^?2. The loading amount of NiO in the prepared electrocatalyst significantly affects its electrocatalytic performance. NiO/Gt?15 exhibits the highest urea oxidation current density with the desired stability. The lower Tafel slope, charge transfer resistance and the higher exchange current density and diffusion coefficient values of urea molecules at NiO/Gt?15 surface elect its application as a promising electrocatalyst material during urea oxidation reaction in fuel cells.