Ethylene Glycol Electrooxidation Research Articles

Polyol assisted formaldehyde reduction of bi-metallic Pt-Pd supported agro-waste derived carbon spheres as an efficient electrocatalyst for formic acid and ethylene glycol oxidation

This report explains, (i) the preparation of carbon spheres (CS) from agro-waste through hydrothermal carbonization (HTC) followed by high temperature carbonization, (ii) the decoration of bi-metallic Pt-Pd nanoparticles (Pt-Pd NPs) with different compositions (Pt/C, Pt0.5Pd1/C, Pt1Pd1/C and Pt1Pd0.5/C, Pd/C) on the carbon by ethylene glycol solvated polyol assisted formaldehyde reduction method and (iii) subsequently used as the electrocatalyst for formic acid (FA) and ethylene glycol (EG) electro-oxidation. The structural and morphological properties of the electrocatalysts were studied using advanced physicochemical characterization techniques. The obtained results well evidence the homogeneous dispersion of Pt-Pd NPs on the surface of the carbon. Especially, Pt0.5Pd1/C exhibited excellent electrocatalytic property towards formic acid electro-oxidation reaction (FAOR) with a higher current density (256 mA cm−2) and stability due to “third body effect”. On the other hand, Pt1Pd0.5/C expressed superior electrochemical performance towards ethylene glycol electro-oxidation reaction (EGOR) due to the strong interaction between high Pt content and Pd. Hence, this work reveals the improved electrocatalytic performance of bi-metallic Pt-Pd NPs supported biomass-derived carbon as a promising anodic electrocatalyst towards FAOR and EGOR.

Palladium/Copper Alloy Hollow Nanocubes Supported on Sulfur‐doped Graphene as Highly Efficient Catalyst for Ethylene Glycol Oxidation

AbstractTo control and regulate both the shape and size of metal nanoparticles is essential for the design and preparation of active and stable catalysts for fuel cell reactions such as the ethylene glycol (EG) electrooxidation reaction, which is highly sensitive to the structure of the catalysts. We report the synthetic strategy of PdCu alloy hollow nanocube supported on sulfur‐doped graphene (H‐PdCu/SG) catalyst through a self‐assembled hydrothermal process for ethylene glycol (EG) electrooxidation reaction. The as‐prepared hollow PdCu alloy nanocubes are well distributed on the SG surface with a relatively small particle size distribution. Additionally, the H‐PdCu/SG catalyst shows a superior electrocatalytic activity and stability toward EG oxidation.

Effect of molybdenum content on the morphology and electronic characteristics of Pd–MoOx nanomaterials and activity evaluation for ethylene glycol electro–oxidation

In this work, Pd–MoOx nanomaterials were developed changing the Mo/Pd precursor ratio and tested for ethylene glycol electro–oxidation reaction (EGOR) in alkaline medium. Mo atomic % compositions of 0, 15, 35, 45 and 75 at. % were evaluated. The increase of Mo at. % resulted in morphology changes due to the directing effect of hexadecyltrimethylammonium bromide (CTAB) on molybdenum passing from hemispheres to nanobelts + hemispheres (15 at. % Mo denoted as Pd85Mo15), then only nanobelts (35 at. % Mo, Pd65Mo35), and nanosheets (45 at. % Mo, Pd55Mo45), and hemispheres were newly obtained at the higher Mo concentration (75 at. % Mo, Pd25Mo75). The activity evaluation of EGOR at 60 °C indicated that Pd25Mo75 supported on Vulcan carbon (Pd25Mo75/C) displayed the highest current density (63.80 mA cm−2), and according with X–ray photoelectron spectroscopy (XPS) the highest activity of Pd25Mo75/C can be related to the abundance of Mo5+ species, which have oxygen vacancies with a single positive charge. Additionally, the analysis of O 1s core–level corroborated the abundance of oxygen with high number of defects sites. Thereby, it was found that Pd loading can be decreased without comprising the activity by increasing oxygen vacancies of MoOx as co–catalyst.

Ultrafine bimetallic alloy supported on nitrogen doped reduced graphene oxide toward liquid-fuel oxidation: Profile of improved performance and extended durability

Herein, the ultrafine bimetallic alloy supported on nitrogen doped reduced graphene oxide (PtCu/NrGO) has been developed via wet-reflux strategy and applied as potential catalyst for electro-oxidation of liquid fuels in direct alcohol fuel cells (DAFCs). Possible conversion to PtCu/NrGO from the precursor materials was established in detail using transmission electron microscope (TEM), field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photo electron spectroscopy (XPS). The coupled structure of PtCu along with NrGO endowed an efficient catalyst with excellent catalytic activity and stability toward electro-oxidation of various alcohols compared to commercial Pt/C in acidic electrolyte. PtCu/NrGO exhibits the mass activity of 0.917, 0.620 and 0.495 A/mgPt toward the electro-oxidation of methanol, ethylene glycol and glycerol, about 6.8, 6.3 and 8.6 fold increment compared to Pt/C catalyst, respectively. Besides, PtCu/NrGO shows excellent durability with less activity decay even after 500 cycles.

Excavated and dendritic Pt-Co nanocubes as efficient ethylene glycol and glycerol oxidation electrocatalysts

Noble metal electrocatalysts with excavated and dendritic architectures have recently attracted growing attention for their large accessible surface areas and high density of under-coordinated atoms. However, it is a tough challenge to avoid the atoms migrating to the corners and kinks and finally obtain the excavated structure, after the complicated interaction among multiple factors during the synthesis process, let alone the growth control of dendritic shape. Herein we demonstrate a facile strategy to synthesize Pt-Co nanocubes having excavated and dendritic structure (Pt-Co EDNCs). Specifically, the Pt-Co EDNC nanocrystal is composed of a deeply excavated nanocube and nanodendrites selectively protruding on the vertexes. Further electrocatalytic investigations showed that Pt-Co EDNCs exhibited enhanced catalytic properties towards the electro-oxidation of ethylene glycol and glycerol compared with commercial Pt/C, which could be attributed to both its unique structure and the synergism between Pt and Co.

Pd-Ru-Bi nanoalloys modified three-dimensional reduced graphene oxide/MOF-199 composites as a highly efficient electrocatalyst for ethylene glycol electrooxidation

Abstract Well-dispersed trimetallic Pd-Ru-Bi alloy nanoparticles (NPs) were successfully embedded in the three-dimensional (3D) rGO/MOF-199 by a facile hydrothermal and in situ impregnation-reduction method. Among the mono-, bi- and tri-metal@rGO/MOF-199 electrocatalysts, the trimetallic PdRuBi@rGO/MOF-199 exhibited the highest catalytic activity and durability towards ethylene glycol oxidation reaction (EGOR) under the alkaline condition, as high as 213.93 mA cm−2, is about 7.23 times higher than that of commercial Pd/C. The outstanding electrocatalysis oxidation performance of the PdRuBi@rGO/MOF-199 is attributed to the unique 3D structures with trimetallic composition and strong synergistic effects of Pd, Ru and Bi nanoalloys that providing plenty of interfaces and achievable reaction active sites. Furthermore, the introduction of GO in MOF-199 matrix conduces to the superior electron transfer and large surface area, which are beneficial to improve the catalytic ability of the catalyst. The study on the new composites offers a conception and applicable way to develop the advanced Pd-based electrocatalysts for high performance direct ethylene glycol fuel cells.

Palladium/Copper Nanoalloy Supported on Carbon Nanotubes for the Electrooxidation of Methanol and Ethylene Glycol

AbstractHerein, we demonstrate the ultrasonic‐assisted synthesis of Palladium/Copper nanoalloy supported on carbon nanotubes (PdCu/CNT) towards the electro‐oxidation of methanol and ethylene glycol using Triton X‐100 as a stabilizer. Structural and morphological analysis manifests the formation of PdCu nanoalloy on the surface of CNTs. For the electrochemical comparison, PdCu on Vulcan carbon (PdCu/VC) also synthesized in the same procedure and characterized thoroughly. The electrochemical evaluations of the PdCu/CNT reveal the better mass activity of 1021.6 mA mg[pd]−1 which is 1.6‐fold higher than PdCu/VC and 5.9 times advanced than commercial Pd/C catalysts towards methanol electrooxidation. Also, for electrooxidation of ethylene glycol, the mass activity of the PdCu/CNT is more of about 1219.8 mA mg[pd]−1 which is around 1.7 times enhanced than PdCu/VC and 4.1 times improved than commercial Pd/C catalysts. Furthermore, sonochemically prepared PdCu/CNT provides improved stability up to 3600s in both methanol and ethylene glycol oxidation reactions. The accredited activity enhancement due to its unique construction of zero‐dimensional structured PdCu nanoalloy with one‐dimensional CNTs and modified electronic effect of Pd on it.

Monodispersed bimetallic platinum-copper alloy nanospheres as efficient catalysts for ethylene glycol electrooxidation

Designing and fabricating highly active and efficient catalysts are of vital importance for the practical applications of direct ethylene glycol fuel cells (DEGFCs). In this study, we employ a feasible one-pot synthetic method to construct highly monodispersed PtCu nanospheres (NSs) as high-efficiency anode electrocatalysts for DEGFCs. Interestingly, the optimized carbon supported Pt1Cu1 NSs can display the highest mass activity of 2146.9 mA mg−1 in 1 M KOH + 1 M EG solution under the scan rate of 50 mV s−1, which is 1.9 times higher than that of commercial Pt/C catalysts. This is ascribed to the favorable electronic effect between Pt and Cu, which is beneficial for ethylene glycol oxidation reaction (EGOR) in fuel cells. Meanwhile, such monodispersed Pt1Cu1 NSs can also exhibit excellent durability, where the Pt1Cu1 catalyst retains 62.6% of the initial value after the cyclic voltammetry of 500 cycles. This work not only provides a significant approach for designing catalysts for fuel cells, but also constructs a novel class of active and stable electrocatalysts for EGOR.

Electro-oxidation of ethylene glycol on Pt[sbnd]Co metal synergy for direct ethylene glycol fuel cells: Reduced graphene oxide imparting a notable surface of action

Slow electro-oxidation reaction and low power output are two major limiting factors in successful commercialization of fuel cell technology. An efficient and stable electro-catalyst with effectual metal combination supported on a durable matrix may provide a viable solution to overcome these issues. The direct ethylene glycol fuel cell consisting of bimetallic anode catalysts are expected to lead out the high-power output issues. In the present paper, we emphasized on the synthesis of a high performing CO poisoning resistant Pt based binary anode catalysts for the electro-oxidation of ethylene glycol (EG) using a chemical reduction route. The electrocatalysts consists of PtCo alloy nanoparticles with different composition of Pt and Co, supported on reduced graphene oxide (rGO). Physical characterizations revealed the formation of bi-metallic catalysts within the size ranges from 2 nm to 3 nm. Electrochemical analysis revealed that PtxCoy/rGO electrocatalyst with x: y molar ratio of 1:9 imparts the highest peak current and power density as compared to commercially available Pt/C and PtCo/C anode catalysts for ethylene glycol electro-oxidation. The power density (81.1 mW/cm2) obtained using PtxCoy/rGO with x:y molar ratio of 1:9 metal catalyst in DEGFC is more than other synthesized catalysts at an operating temperature of 100 °C and the operating pressure of 1 bar with 2 M ethylene glycol as anode fuel and anode and cathode platinum metal loading of 2 mg/cm2.

Ultrafine two-dimensional alloyed PdCu nanosheets-constructed three-dimensional nanoflowers enable efficient ethylene glycol electrooxidation

Constructing efficient catalysts for the electrooxidation of fuels is of vital importance for realizing the commercialization of fuel cells. Unfortunately, most of catalysts (e.g. Pt) suffer from limited activity and poor durability for the electrooxidation of liquid fuel. Also, the drawbacks of extremely high cost and nature scarcity have also severely hindered their large-scale applications. Here, we demonstrated the synthesis of a new class of well-defined and three-dimensional (3D) flower-like nanocatalysts which assembled by ultrafine two-dimensional (2D) alloyed PdCu nanosheets. Structurally, the as-obtained PdCu alloy nanoflowers (NFs) possessed high surface area with abundant surface active sites. Benefiting from the unique structural properties and the strong alloy effect, the as-obtained PdCu NFs can display greatly enhanced performances toward ethylene glycol oxidation reaction (EGOR) with the mass/specific activity of 4714.1 mA mg−1/13.7 mA cm−2, which are 4.4 and 6.85 times of Pd/C catalysts, respectively. Most strikingly, such 2D nanosheets-constructed 3D nanoflower-like structure also enables the PdCu catalysts with high long-term stability for EGOR. As a proof of concept, this work not only presents the rational design and construction of catalysts with well-defined structure for the fuel cells reactions but also provides a promising method to largely promote the electrochemical performances of catalysts.

The Catalytic Activity of Pt:Ru Nanoparticles for Ethylene Glycol and Ethanol Electrooxidation in a Direct Alcohol Fuel Cell

In this study, we investigated the carbon-supported PtRu nanoparticles with atomic ratios of Pt:Ru of 100:0, 90:10, 70:30, and 50:50 for ethanol and ethylene glycol electrooxidation in alkaline media. The nanoparticles were synthesized using sodium borohydride method with 20 wt% of metals loading on carbon. The nanoparticle mean sizes were 7.3 nm, 5.7 nm, 5.2 nm, and 5.1 nm for Pt/C, Pt90Ru10/C, Pt70Ru30/C, and Pt50Ru50/C, respectively. X-ray diffraction (XRD) analysis revealed that Pt and PtRu electrocatalysts have face-centered cubic (fcc) structure and suggests the alloy formation for all PtRu/C materials, which was further supported by the X-ray photoelectron spectroscopy (XPS). Based on XPS analysis, Pt50Ru50/C has higher amount of Pt oxides on the surface than Pt70Ru30/C. Electrochemical results demonstrated that the addition of Ru to Pt enhances the catalytic activity towards ethanol and ethylene glycol electrooxidadion. The catalyst of Pt50Ru50/C composition showed the lowest onset potential for ethanol and ethylene glycol electrooxidation, which were 160 and 70 mV lower than for Pt/C, respectively. Furthermore, this catalyst outperformed Pt/C and other PtRu/C compositions in chronoamperometric and direct alcohol fuel cell (DAFC) experiments. DAFC experiments using Pt50Ru50/C as anode had the power density 40 and 14% higher than using Pt/C for ethanol and ethylene glycol, respectively. The promotion is due to the bi-functional mechanism and/or electronic effect of two metals in the alloy.

Ultrafine Pt Nanoparticles Stabilized by MoS2/N-Doped Reduced Graphene Oxide as a Durable Electrocatalyst for Alcohol Oxidation and Oxygen Reduction Reactions.

Direct alcohol fuel cells play a pivotal role in the synthesis of catalysts because of their low cost, high catalytic activity, and long durability in half-cell reactions, which include anode (alcohol oxidation) and cathode (oxygen reduction) reactions. However, platinum catalysts suffer from CO tolerance, which affects their stability. The present study focuses on ultrafine Pt nanoparticles stabilized by flowerlike MoS2/N-doped reduced graphene oxide (Pt@MoS2/NrGO) architecture, developed via a facile and cost-competitive approach that was performed through the hydrothermal method followed by the wet-reflux strategy. Fourier transform infrared spectra, X-ray diffraction patterns, Raman spectra, X-ray photoelectron spectra, field-emission scanning electron microscopy, and transmission electron microscopy verified the conversion to Pt@MoS2/NrGO. Pt@MoS2/NrGO was applied as a potential electrocatalyst toward the anode reaction (liquid fuel oxidation) and the cathode reaction (oxygen reduction). In the anode reaction, Pt@MoS2/NrGO showed superior activity toward electro-oxidation of methanol, ethylene glycol, and glycerol with mass activities of 448.0, 158.0, and 147.0 mA/mgPt, respectively, approximately 4.14, 2.82, and 3.34 times that of a commercial Pt-C (20%) catalyst. The durability of the Pt@MoS2/NrGO catalyst was tested via 500 potential cycles, demonstrating less than 20% of catalytic activity loss for alcohol fuels. In the cathode reaction, oxygen reduction reaction results showed excellent catalytic activity with higher half-wave potential at 0.895 V versus a reversible hydrogen electrode for Pt@MoS2/NrGO. The durability of the Pt@MoS2/NrGO catalyst was tested via 30 000 potential cycles and showed only 15 mV reduction in the half-wave potential, whereas the Pt@NrGO and Pt-C catalysts experienced a much greater shift (Pt@NrGO, ∼23 mV; Pt-C, ∼20 mV).

Palladium-loaded tantalum oxide modified Pt electrode toward electrochemical oxidation of ethylene glycol

The study of the microstructure and electrochemical property of palladium-loaded tantalum oxide (Pd/Ta2O5) particles is presented. Pd/Ta2O5 belongs to the orthorhombic phase. The palladium states onto the Pd/Ta2O5 surface are Pd0 and Pd2+ forms. From the morphology and size analysis of the loaded Pd particles using transmission electron microscopy, one can see that the nanosized-Pd particles are loaded onto the Ta2O5 surface. A Pd/Ta2O5 film-modified Pt (Pd/Ta2O5-Pt) electrode further exhibits excellent catalytic activity toward electro-oxidation of ethylene glycol (EG) in acid conditions. Density functional theory was also utilized to clarify the effect on microstructure of Ta2O5 after Pd loading showing that the density of states is increased and the density of electrons in the loading region is enlarged after Ta2O5 is loaded with Pd. Therefore, Pd loading improves the conductivity and electrochemical property of the Pd/Ta2O5-Pt electrode.

Uniform PdCu coated Te nanowires as efficient catalysts for electrooxidation of ethylene glycol

The renewable alcohol oxidation reaction is critical to conversion and storage of clean energy, but the design and construction of highly efficient catalysts for boosting the electrooxidation reaction, remains a grand challenge. Here, we propose a facile approach for the large-scale generation of uniform PdCuTe nanowires (NWs) by using Te NWs as the template. Impressively, as a robust integrated one-dimensional (1D) anode catalyst, the as-obtained PdCuTe NWs shows high specific/mass activity of 7.9 mA cm−2 and 3872.6 mA mg−1 for the ethylene glycol (EG) oxidation reaction, being 3.4 and 4.2-fold enhancement than commercial Pd/C, respectively. Moreover, the ternary PdCuTe nanowires also display excellent stability with less activity degradation after long-term electrochemical tests. Combining physicochemical characterizations and electrochemical results, we found that the 1D Te NWs template was significant for promoting the electrocatalytic activity of PdCuTe NWs, because such nanowire template was the key, leading to the attachment of active PdCu nanoparticles which successfully exposed abundant active sites and contributed to large promotion of electrocatalytic performances. This work highlights the utilization efficiency improvement via morphology design for the promotion of electrocatalytic performances.

Facile Synthesis of a Tailored-Designed Au/Pt Nanoanode for Enhanced Formic Acid, Methanol, and Ethylene Glycol Electrooxidation

The recent revolution in nanoscience and global energy demand have motivated research in liquid fuel cells (LFCs) due to their enhanced efficiency, moving flexibility, and reduced contamination. In line with this advancement, a glassy carbon (GC) electrode was modified with platinum (PtNPs) and gold (AuNPs) nanoparticles to fabricate a nanosized anode for formic acid, methanol, and ethylene glycol electrooxidation (abbreviated, respectively, to FAO, MO, and EGO), of the key anodic reactions of LFCs. The deposition sequence of the catalyst’s layers was important where the Au/Pt/GC electrode (in which PtNPs were directly deposited onto the GC surface followed by AuNPs—surface coverage ≈ 32%) exhibited the best catalytic performance. The catalytic performance of the Au/Pt/GC anode excelled (at least threefold) its value obtained at the Pt/GC anode with regard to FAO and EGO, if the oxidation peak currents were compared. This enhancement got reduced to 1.4 times in the case of MO, but the large decrease (− 220 mV) in the onset potential of MO provided compensation. The role of AuNPs in the Au/Pt/GC catalyst was principal in boosting its catalytic performance as it immunized the underlying PtNPs against CO poisoning which is associated with the release of CO as an intermediate during the oxidation. Interestingly, AuNPs succeeded in interrupting the contiguity of the Pt surface sites required for CO adsorption during FAO, MO, and EGO and, thus, presage preventing the deterioration of the catalytic performance of their corresponding LFCs.

Composition optimized trimetallic PtNiRu dendritic nanostructures as versatile and active electrocatalysts for alcohol oxidation

Platinum-based nanocrystals are the most effective electrocatalysts for accelerating the chemical transformations on the anode in direct alcohol fuel cells. To facilitate practical applications and overcome the drawbacks of diverse alcohols, it is significant to develop electrocatalysts with high activities and a wide fuel flexibility. Here, we demonstrate a practicable solution method for fabricating composition tunable trimetallic PtNiRu dendritic nanostructures (DNSs) which can serve as versatile and active catalysts for electrooxidation of a variety of liquid alcohols. A series of trimetallic DNSs with tunable Pt/Ni/Ru atomic ratios were successfully synthesized by simply adjusting the feeding of precursors. Detailed electrochemical test indicates that, among other compositions, the Pt66Ni27Ru7 DNSs present much superior electroactivity in catalyzing electrooxidation of liquid alcohols in acidic mediums. Specifically, the mass activity and specific activity on the Pt66Ni27Ru7 DNSs, for electrooxidation of methanol, ethanol, and ethylene glycol, are 4.57 and 4.34 times, 3.55 and 3.42 times, and 2.37 and 2.28 times that of the commercial Pt black, respectively. X-ray photoelectron spectroscopy and CO stripping studies reveal the adsorption of CO on these PtNiRu DNSs is much weaker than on pure Pt. Meanwhile, the surface Ru sites can provide neighbouring–OH groups to facilitate the oxidation and removal of the adsorbed intermediates (–CO) on the surface Pt sites, effectively improving the CO tolerance of the catalysts. The PtNiRu DNSs also show effectively boosted capacity for breaking the C–C bond in C2-alcohols, showing great potential for fuel-flexible fuel cell applications.

EIS-Activity Correlation for the Electro-Oxidation of Ethylene Glycol at Nanoparticles-Based Electrocatalysts

Enhanced catalysis of ethylene glycol electro-oxidation (EGO) is reported at a ternary CoOx/NiOx/Pt catalyst in which Pt nanoparticles (nano-Pt), nickel oxide nanoflowers (nanoNiOx), and cobalt oxide nanoparticles (nano-CoOx); are respectively electrodeposited onto a glassy carbon (GC) substrate. The electrocatalytic activity of the catalyst toward EGO depends on the catalyst's composition, loading sequence and loading level besides the electrolyte's pH and temperature. A detailed morphological, compositional, and structural inspection for the catalyst is achieved by FE-SEM, energy dispersive X-ray spectroscopy, and X-ray diffraction, respectively. Cyclic voltammetry is employed to ensure the successful electrodeposition of the catalyst's ingredients and to assess its activity. The superiority of the CoOx/NiOx/Pt/GC catalyst over a series of catalysts employing different ingredients and/or deposition sequence is demonstrated. It supports a larger (ca. fourfold) oxidation peak current, and a significant (ca. ‒330 mV) negative shift in the onset potential of EGO together with a much more enhanced long-term stability toward continuous electrolysis when compared to the Pt catalyst. The novelty of this investigation extends to employing the electrochemical impedance spectroscopy (EIS) as a probe that provides important information about the reaction pathway of EGO. Interestingly, the maximum capacitance obtained at the CoOx/NiOx/Pt/GC catalyst (coincides with the EGO peak current) is fivefold higher than that obtained at the Pt/GC catalyst at ‒0.35 V vs. Ag/AgCl. Formic acid and oxalic acid were the major products of EGO, as revealed by high performance liquid chromatography.

High performance of AuPt deposited on Ni nanoparticles in ethylene glycol oxidation

The electrochemical deposition of small amounts of Au and Pt on the surface of Ni nanoparticles supported on reduced graphene oxide and the electrooxidation of ethylene glycol on the AuPt-decorated Ni/reduced graphene oxide catalysts in alkaline solution are investigated. By selecting a short deposition time, a low concentration of metal precursors, and a positive applied potential, AuPt loadings of less than 1.0 μg cm−2 are obtained. Physical and electrochemical characterizations of AuPt/Ni/reduced graphene oxide reveal a much lower content of Pt relative to Au. However, AuPt/Ni/reduced graphene oxide behaves similar to monometallic Pt/reduced graphene oxide rather than to Au/reduced graphene oxide in ethylene glycol oxidation, while Ni/reduced graphene oxide and Pt-decorated Ni/reduced graphene oxide show no activity. Compared to Pt/reduced graphene oxide or Au/reduced graphene oxide, the peak intensities of AuPt/Ni/reduced graphene oxide are somewhat higher in terms of the glassy carbon substrate, but are significantly higher in terms of the AuPt mass loading. Another attractive feature of AuPt/Ni/reduced graphene oxide is low cost resulted from the low AuPt loading. The result of this study indicates that decorating the surface of non-noble metal with a small amount of two noble metals is an efficient method to fabricate highly active catalysts.

Alcohol electrooxidation study on carbon nanotube supported monometallic, Pt, Bi, and Ru catalysts

In the present study, carbon nanotube supported Pt (Pt/CNT), Bi (Bi/CNT), and Ru (Ru/CNT) catalysts are prepared via NaBH4 reduction method for ethanol (C2H5OH), ethylene glycol (C2H6O2), and methanol (CH3OH) electrooxidation. The physical characterization of these as-prepared catalysts is performed by X-ray diffraction (XRD). Furthermore, electrochemical measurements are conducted via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and linear sweep voltammetry (LSV). Pt/CNT catalyst exhibits the highest catalytic activity and stability compared to Bi (Bi/CNT) and Ru (Ru/CNT) catalysts. It is observed that the electrocatalytic activity of Pt/CNT catalyst for ethylene glycol (C2H6O2) oxidation is higher than its electrocatalytic activities for ethanol (C2H5OH) and methanol (CH3OH) oxidation. Maximum current density of C2H6O2 of Pt/CNT catalyst is about 4 and 5.7 times lower than C2H5OH and CH3OH. Furthermore, electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and linear sweep voltammetry (LSV) results are in good agreement with CV results in terms of stability and electrocatalytic activity of Pt/CNT. The Pt/CNT catalyst is believed to be a promising anode catalyst for the alcohol fuel cells.

One-pot construction of N-doped graphene supported 3D PdAg nanoflower as efficient catalysts for ethylene glycol electrooxidation

Rational design and support introduction of electrocatalysts are significant for the improvement of their performances for electrooxidation reaction, but still a grand challenge. Herein, we developed a facile one-pot method to construct a unique class of N-doped graphene supported three-dimensional (3D) PdAg nanoflowers catalysts (denoted as PdAg NFs/NG) under the room temperature. It is found that the introduction of NG is beneficial for reducing the diameter of 3D PdAg NFs, where the synthesized PdAg NFs/NG show significantly enhanced electrocatalytic performances towards ethylene glycol oxidation reaction (EGOR). Specifically, benefiting from strong synergistic effect, modified electronic structure, largely improved conductivity, and high surface active areas, the resultant PdAg NFs/NG demonstrate the mass and specific activity of 5765.3 mA mg−1 and 11.9 mA cm−2 for the ethylene glycol electrooxidation, which are 5.4 and 5.95 times higher than those of commercial Pd/C catalysts, respectively. More importantly, after the successful introduction of NG, the PdAg NFs/NG also displays great improvement in durability, which retains the mass activity of 4208.7 mA mg−1 after long-term electrochemical measurement, 2.62 and 20.1 times larger than 3D PdAg NFs and Pd/C catalysts. The present work manifests the facile construction of advanced nanocatalysts with optimized functional properties.