Electrocatalysts For Direct Methanol Fuel Cells Research Articles

CeO2-supported Pt nanoclusters for improved electrochemical oxidation of methanol

Developing highly durable and active Pt-supported catalysts is currently the most prominent and practicable electrocatalyst design strategy for direct methanol fuel cells (DMFC) due to their high electrocatalytic stability and activity. Herein, we fabricated CeO2 nanorods with tiny Pt nanoparticles that possess good electrocatalytic behavior for methanol oxidation reaction (MOR). In addition, the presence of Ce3+ and small Pt nanoparticles (3.46 nm) enhanced strong metal interaction, facilitating the formation of oxygen vacancies on the CeO2 surface to boost the MOR performance. Hence, the Pt-CeO2 catalyst revealed high mass activity (1414.0 mA mg−1) and areal-specific activity (1.615 mA cm−2) towards MOR in an acidic electrolyte, which was three times that of the 20% Pt/C catalyst (545.4 mA mg−1 and 0.856 mA cm−2). Besides, the Pt-CeO2 catalyst exhibited excellent performance of MOR in an alkaline electrolyte and retained 90.44% of its initial mass activity after 5000 cycles due to the unique morphology and synergistic effects between Pt and CeO2. Pt-CeO2 is regarded as a promising MOR electrocatalyst for DMFC applications.Graphical

TiO2 Nanolayer–Coated Carbon as Pt Support for Enhanced Methanol Oxidation Reaction

Abstract To facilitate the large-scale application of direct methanol fuel cells (DMFCs), the issue of low Pt/C durability due to Pt degradation and carbon corrosion in harsh DMFC operating conditions must be addressed. A promising strategy is to hybridize metal oxides with carbon materials, resulting in a durable and conductive support that exhibits a strong metal-support interaction (SMSI) effect on platinum nanoparticles (Pt NPs). In this study, we introduced a TiO2 coating on carbon black, creating a TiO2 nanolayer between Pt and carbon black. The nanolayer not only protects the carbon black but also activates the SMSI effect on Pt. The resulting Pt/C@TiO2 electrocatalyst exhibits superior durability than commercial Pt/C. After the accelerated durability test, the mass activity loss of the methanol oxidation reaction (MOR) of Pt/C@TiO2 (32%) is significantly lower than that of Pt/C (46.8%). Moreover, the MOR activity of Pt/C@TiO2 is higher than Pt/C as well. It suggests that Pt/C@TiO2 shows great potential as a highly durable and active electrocatalyst for DMFCs.

Anodic Catalyst Support via Titanium Dioxide-Graphene Aerogel (TiO2-GA) for A Direct Methanol Fuel Cell: Response Surface Approach

The direct methanol fuel cell (DMFC) has the potential for portable applications. However, it has some drawbacks that make commercialisation difficult owing to its poor kinetic oxidation efficiency and non-economic cost. To enhance the performance of direct methanol fuel cells, various aspects should be explored, and operational parameters must be tuned. This research was carried out using an experimental setup that generated the best results to evaluate the effectiveness of these variables on electrocatalysis performance in a fuel cell system. Titanium dioxide-graphene aerogel (TiO2-GA) has not yet been applied to the electrocatalysis area for fuel cell application. As a consequence, this research is an attempt to boost the effectiveness of direct methanol fuel cell electrocatalysts by incorporating bifunctional PtRu and TiO2-GA. The response surface methodology (RSM) was used to regulate the best combination of operational parameters, which include the temperature of composite TiO2-GA, the ratio of Pt to Ru (Pt:Ru), and the PtRu catalyst composition (wt%) as factors (input) and the current density (output) as a response for the optimisation investigation. The mass activity is determined using cyclic voltammetry (CV). The best-operating conditions were determined by RSM-based performance tests at a composition temperature of 202 °C, a Pt/Ru ratio of (1.1:1), and a catalyst composition of 22%. The best response is expected to be 564.87 mA/mgPtRu. The verification test is performed, and the average current density is found to be 568.15 mA/mgPtRu. It is observed that, after optimisation, the PtRu/TiO2-GA had a 7.1 times higher current density as compared to commercial PtRu. As a result, a titanium dioxide-graphene aerogel has potential as an anode electrocatalyst in direct methanol fuel cells.

Mixed-Dimensional Pt-Ni Alloy Polyhedral Nanochains as Bifunctional Electrocatalysts for Direct Methanol Fuel Cells.

Pt nanocatalysts play a critical role in direct methanol fuel cells (DMFCs) due to their appropriate adsorption/desorption energy, yet suffer from an unbalanced relationship between size-dependent activity and stability. Herein, mixed-dimensional Pt-Ni alloy polyhedral nanochains (Pt-Ni PNCs) with an ordered assembly of a nanopolyhedra-nanowire-nanopolyhedra architecture are fabricated as bifunctional electrocatalysts for DMFCs, effectively alleviating the size effect. The Pt-Ni PNCs exhibit 7.23 times higher mass activity for the anodic methanol oxidation reaction (MOR) than that of commercial Pt/C. In situ Fourier transform infrared spectroscopy and CO stripping measurements demonstrate the prominent stability of the Pt-Ni PNCs to resist CO poisoning. For the cathodic oxygen reduction reaction (ORR), a positive half-wave potential exceeding Pt/C is achieved by the Pt-Ni PNCs, and it can be well maintained for 10000 cycles with negligible activity decay. The designed nanostructure can alleviate the agglomeration and dissolution problems of 0D small-sized Pt-Ni alloy nanocrystals and enrich surface atom steps and active facets of 1D chain-like nanostructures. This work provides a proposed strategy to improve the catalytic performance of Pt-based nanocatalysts by constructing novel interfacial relationships in mixed dimensions to alleviate the imbalance between catalytic activity and catalytic stability caused by size effects.

Three‐Dimensional Porous Low‐Defect Carbon Nanotube and Graphene Network Supported Rh Nanocrystals as Efficient Methanol Oxidation Electrocatalysts

AbstractWith the rapid economic development and urgent environmental demands, the direct methanol fuel cell (DMFC) as one of environmental‐friendly energy‐conversion systems has attracted wide attention in the world, while the insufficient activity and low structural stability of the anode Pt/carbon catalyst largely deteriorate its overall performance. Herein, we report a facile and cost‐effective bottom‐up method to the fabrication of rhodium nanocrystals supported by three‐dimensional (3D) porous hybrid networks constructed from low‐defect carbon nanotubes and reduced graphene oxide (Rh/LCNT‐RGO) as Pt‐alternative electrocatalysts for DMFC. Such a structural design gives the resultant Rh/LCNT‐RGO hybrid a series of fantastic architectural advantages, such as the large specific surface area of 3D interconnected graphene configuration, high electrical conductivity of low‐defect carbon nanotubes, and abundant catalytically active sites of well‐dispersive Rh nanocrystals. As a consequence, the Rh/LCNT‐RGO hybrid displays unusual catalytic abilities towards the methanol electrooxidation, including a large electrochemically active surface area of 123.8 m2 g−1, a high mass activity of 1228.5 mA mg−1, strong poison tolerance, and long lifespan, far surpassing those of reference Rh/carbon black, Rh/acid‐treated CNT, and Rh/RGO catalysts.

Methanol Tolerant Oxygen Reduction Reaction Electrocatalysis using Size‐Specific Triphenylphosphine‐Ligated Gold Nanoclusters

AbstractThe development of a stable and efficient Oxygen Reduction Reaction (ORR) electrocatalysts with high methanol tolerance is crucial for Direct Methanol Fuel Cells (DMFCs). Herein, triphenylphosphine (PPh3)‐ligated gold nanoclusters and complexes (AuNCs), Au101(PPh3)21Cl5, Au9(PPh3)8(NO3)3, and Au1(PPh3)Cl supported on reduced graphene oxide (rGO) have been explored as methanol tolerant ORR electrocatalysts. Electrocatalytic performance of each AuNCs‐rGO was determined through linear sweep voltammograms (LSV) and cyclic voltammetry (CV) and compared with Pt/C. Size‐dependent ORR activity was observed which followed the size trend of Au101NC‐rGO>Au9NC‐rGO>Au1NC‐rGO. Repeated LSV and chronoamperometry measurements revealed that the long‐term stability over 24 hours followed the trend Au101NC‐rGO>Au9NC‐rGO∼Au1NC‐rGO and all were more stable than Pt/C. The methanol tolerance of each AuNCs‐rGO was also evaluated via LSV and CV. Size‐independent methanol tolerance with no noticeable change in ORR performance of AuNCs‐rGO was observed in the presence of methanol. AuNCs‐rGO nanocomposites are promising cathode electrocatalysts for DMFCs.

NiPd Supported on Mesostructured Silica Nanoparticle as Efficient Anode Electrocatalyst for Methanol Electrooxidation in Alkaline Media

The direct methanol fuel cell (DMFC) is a portable device and has the potential to produce 10 times higher energy density than lithium-ion rechargeable batteries. It is essential to build efficient methanol electrooxidation reaction electrocatalysts for DMFCs to achieve their practical application in future energy storage and conversion. A catalyst consisting of nickel–palladium supported onto mesostructured silica nanoparticles (NiPd–MSN) was synthesized by the wet impregnation method, while MSN was synthesized using the sol-gel method. MSN act as a catalyst support and has very good characteristics for practical support due to its large surface area (>1000 m2/g) and good chemical and mechanical stability. The microstructure and catalytic activity of the electrocatalysts were analyzed by X-ray diffraction (XRD), Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM), Brunauer–Emmet–Teller (BET) theory, X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and chronoamperometry (CA). XRD showed that the NiPd–MSN electrocatalysts had a high crystallinity of PdO and NiO, while FESEM displayed that NiPd was dispersed homogeneously onto the high surface area of MSN. In alkaline media, the catalytic activity toward the methanol oxidation reaction (MOR) of NiPd–MSN demonstrated the highest, which was 657.03 mA mg−1 more than the other electrocatalysts. After 3600 s of CA analysis at −0.2 V (vs. Ag/AgCl), the MOR mass activity of NiPd–MSN in alkaline media was retained at a higher mass activity of 190.8 mA mg−1 while the other electrocatalyst was significantly lower than that. This electrocatalyst is a promising anode material toward MOR in alkaline media.

Bismuth Oxyhydroxide-Pt Inverse Interface for Enhanced Methanol Electrooxidation Performance.

Developing efficient Pt-based electrocatalysts for the methanol oxidation reaction (MOR) is of pivotal importance for large-scale application of direct methanol fuel cells (DMFCs), but Pt suffers from severe deactivation brought by the carbonaceous intermediates such as CO. Here, we demonstrate the formation of a bismuth oxyhydroxide (BiOx(OH)y)-Pt inverse interface via electrochemical reconstruction for enhanced methanol oxidation. By combining density functional theory calculations, X-ray absorption spectroscopy, ambient pressure X-ray photoelectron spectroscopy, and electrochemical characterizations, we reveal that the BiOx(OH)y-Pt inverse interface can induce the electron deficiency of neighboring Pt; this would result in weakened CO adsorption and strengthened OH adsorption, thereby facilitating the removal of the poisonous intermediates and ensuring the high activity and good stability of Pt2Bi sample. This work provides a comprehensive understanding of the inverse interface structure and deep insight into the active sites for MOR, offering great opportunities for rational fabrication of efficient electrocatalysts for DMFCs.

Atomically deviated Pd-Te nanoplates boost methanol-tolerant fuel cells.

The methanol crossover effect in direct methanol fuel cells (DMFCs) can severely reduce cathodic oxygen reduction reaction (ORR) performance and fuel efficiency. As a result, developing efficient catalysts with simultaneously high ORR activity and excellent antipoisoning methanol capability remains challenging. Here, we report a class of Pd-Te hexagonal nanoplates (HPs) with a Pd20Te7 phase that simultaneously overcome the activity and methanol-tolerant issues in alkaline DMFC. Because of the specific arrangement of Pd atoms deviated from typical hexagonal close-packing, Pd-Te HPs/C displays extraordinary methanol tolerance with high ORR performance compared with commercial Pt/C. DFT calculations reveal that the high performance of Pd-Te HPs can be attributed to the breakthrough of the linear relationship between OOH* and OH* adsorption, which leaves sufficient room to improve the ORR activity but suppresses the methanol oxidation reaction. The concurrent high ORR activity and excellent methanol tolerance endow Pd-Te HPs as practical electrocatalysts for DMFC and beyond.

Au@CeO2 nanoparticles supported Pt/C electrocatalyst to improve the removal of CO in methanol oxidation reaction

Direct methanol fuel cells (DMFCs) are emerging as clean and renewable energy sources for global-scale sustainable energy solutions. However, several limitations of the current standard catalyst (platinum supported carbon black: Pt/C) prevent their commercialization. As an effective co-catalyst, Au@CeO2 core-shell structures are greatly advantageous for getting over the remaining hurdles of Pt/C in DMFCs. Herein, we report an efficient approach for the fabrication of electrocatalyst for DMFCs consisting of three components (Pt/C, Au@CeO2 and Pt catalysts) loaded on carbon cloth using spray and electrophoresis deposition methods. The obtained Pt/C-Au@CeO2-Pt electrocatalyst proved to have high electrochemical surface area (ECSA-77.8 m2/gPt) and high methanol oxidation reaction (MOR) activity (1267 mA/mgPt), which were 1.7 and 2.3 times greater than those of Pt/C only (45.6 m2/gPt and 560 mA/mgPt). In addition, the presence of Au@CeO2 nanoparticles can further enhance the stability of the Pt/C-Au@CeO2-Pt electrocatalyst toward the MOR activity. The improved MOR performance of the Pt/C-Au@CeO2-Pt electrocatalyst could be mainly attributed to the production of abundant OHads promoters, reduction of charge transfer resistance and enhancement of Pt catalytic efficient utilization. It helps to wholly oxidize COads intermediate as dominant poisoning species on Pt catalyst, which are often generated during the MOR operation in acidic condition.

Pt Nanowires with High Catalytic Activity and Durability Towards Methanol Oxidation Reaction

Direct Methanol fuel cells (DMFCs) have been attracting great research interest because of their cleanness and high-efficiency in energy conversion1 , 2. Pt catalysts have been used extensively for helping oxidize methanol on the anode side with high catalytic activity and efficiency. However, Pt catalysts are expensive and also suffering from insufficient durability3. To this end, substantial efforts have been devoted to design structure-controllable Pt catalysts. In our recent study, we developed Pt nanowires as electrocatalysts in DMFCs with high catalytic activity and durability for methanol oxidation reaction (MOR) (see Figure 1). Using N, N-Dimethyl form amide (DMF) and N-butanol as both solvent and reductant synergistically, we found that the growth of Pt nanowires highly depends on reaction time and solution ratio. Experimental results showed that all the obtained networked Pt nanowired catalysts exhibit improved durability over those of commercial Pt/C. After 2000 accelerated degradation cycles, the commercial Pt/C electrocatalysts lost ~ 95% of their specific MOR activities, while the Pt nanowired membrane shows only ~70 % loss. Our results suggest that the networked Pt nanowires with high surface areas are promising for MOR of DMFCs. B. C. Steele and A. Heinzel, in Materials For Sustainable Energy: A Collection of Peer-Reviewed Research and Review Articles from Nature Publishing Group, World Scientific, 2011, pp. 224-231.X. Zhao, M. Yin, L. Ma, L. Liang, C. Liu, J. Liao, T. Lu and W. Xing, Energy & Environmental Science, 2011, 4, 2736-2753.J. N. Tiwari, R. N. Tiwari, G. Singh and K. S. Kim, Nano Energy, 2013, 2, 553-578. Figure 1

Impregnated Electroreduced Pt on Ru/C as an Anode Catalyst for Direct Methanol Fuel Cells

Direct methanol fuel cells (DMFC) have attracted considerable attention as an alternative energy source for portable devices due to their advantages of relatively higher energy densities and easy fuel storage. The successful commercialization of DMFC depends heavily on the activity and durability of the electrocatalysts. Pt-Ru nanoparticles supported on carbon are a well-studied anode electrocatalyst for DMFC due to their efficient CO removal ability. In this work, we propose a method for synthesizing Pt on ruthenium-on-carbon support (Pt/RuC) by combining the polyol and impregnation-electroreduction methods. First, ruthenium-on-carbon support (Ru/C) with varying Ru weight percentages (viz. 8, 17, and 30 wt%) was synthesized via the polyol process using ethylene glycol as a reducing agent. Second, Pt was impregnated on Ru/C-coated carbon paper and subsequently electroreduced using square wave pulse deposition. Using this synthesis method produced a smaller and more uniform Pt particle size distribution compared to the conventional electroreduction method. Of the various compositions of the Pt/RuC catalyst synthesized, Pt deposited on 30 wt% Ru/C revealed the highest electrochemical surface area and increased mass activity for methanol oxidation reaction. The anode catalyst, when tested in a DMFC, showed the highest peak power density of 80 mW cm−2 at 80°C. Additionally, a short-term stability test carried out at 100 mA cm−2 for 10 h revealed the superior stability of the electrocatalyst.

Reduced graphene oxide supported PdNi alloy nanocrystals for the oxygen reduction and methanol oxidation reactions

The research on electrocatalysts with relatively lower price than Pt and excellent electrocatalytic performance for the cathode oxygen reduction reaction (ORR) and anode methanol oxidation reaction (MOR) is vital for the development of direct methanol fuel cells (DMFCs). In this work, we develop a cyanogel-reduction method to synthesize reduced graphene oxide (rGO) supported highly dispersed PdNi alloy nanocrystals (PdNi/rGO) with high alloying degree and tunable Pd/Ni ratio. The large specific surface area and the d-band center downshift of Pd result in excellent activity of Pd4Ni1/rGO nanohybrids for the ORR. The modification of Pd electronic structure can facilitate the adsorption of CH3OH on Pd surface and the highly oxophilic property of Ni can eliminate/mitigate the COads intermediates poisoning, which make PdNi/rGO nanohybrids possess superior MOR activity. In addition, rGO improve the stability of PdNi alloy nanocrystals for the ORR and MOR. Due to high activity and stability for the ORR and MOR, PdNi/rGO nanohybrids are promising to be an available bifunctional electrocatalyst in DMFCs.

One-pot synthesis of interconnected Pt95Co5 nanowires with enhanced electrocatalytic performance for methanol oxidation reaction

Shape- and composition-controlled synthesis of platinum-based nanocrystals (NCs) is critical for the development of electrocatalysts that have high activity toward the methanol oxidation reaction (MOR) in direct methanol fuel cells (DMFCs). We report one-pot surfactant-free synthesis of interconnected Pt95Co5 nanowires (NWs) via an oriented attachment process, which has distinct advantages over conventional template- and surfactant-assisted approaches. Enhanced electrochemical activities toward MOR were confirmed through comparison with pure Pt NWs and commercial Pt/C catalyst. Pt95Co5 NWs demonstrated the highest current density during the long-term stability test. These results reveal that the introduction of the 3d-transition metal Co can reduce the catalyst cost and contribute to the improvement of electrochemical performance. The integrated design of interconnected NW structure, bimetallic composition, and clean surfaces in the present system may open a new way to the development of excellent electrocatalysts in DMFCs.

Facile synthesis of three-dimensional platinum nanoflowers on reduced graphene oxide – Tin oxide composite: An ultra-high performance catalyst for methanol electro-oxidation

Herein, we report platinum (Pt) nanoflowers decorated reduced graphene oxide (rGO)–tin oxide (SnO2) composite as an efficient electro-catalyst for direct methanol fuel cells (DMFCs). rGO-SnO2 composite is synthesized by a novel, eco-friendly hydrothermal method using lemon extract followed by electro-deposition of Pt to yield high density Pt nanoflowers uniformly distributed over rGO-SnO2 for superior catalytic performance and optimal utilization of Pt nanostructures. Whilst Pt nanoparticles (NPs)-rGO-SnO2 composite exhibits higher CO tolerance ability (If/Ib = 3) and poor catalytic stability, Pt nanoflowers-rGO-SnO2 composite shows comparable CO tolerance ability (If/Ib = 1.81) with excellent stability. At 3000 s, the current density of Pt nanoflowers-rGO-SnO2 has been found to be 2.1 folds higher than Pt NPs-rGO-SnO2 composite. Excellent durability of Pt nanoflowers-rGO-SnO2 is attributed to the high surface area of Pt nanoflowers which provides more active sites during methanol oxidation without any agglomeration, thus, facilitating diffusion of methanol to Pt for catalytic activity. As per our knowledge, this is the first report on Pt nanoflowers-rGO-SnO2 composite based electro-catalyst for DMFCs that yields superior performances in terms of catalytic efficiency, CO tolerance activity and stability. The composite shows enormous potential to be used as binder free, cost-effective, efficient and durable electro-catalyst for DMFCs applications.

Highly methanol-tolerant platinum electrocatalyst derived from poly(vinylpoyrrolidone) coating

The design and fabrication of a methanol-tolerant electrocatalyst is still one of the most important issues in direct methanol fuel cells (DMFCs). Here, we focus on the design of a cathodic electrocatalyst in DMFCs and describe a new methanol-tolerant electrocatalyst fabricated from poly(vinylpyrrolidone) (PVP) coating on platinum nanoparticles assisted by hydrogen bonding between PVP and polybenzimidazole (PBI). The PVP layer has a negligible effect on the oxygen reduction reaction (ORR) activity, while the methanol oxidation reaction is retarded by the PVP layer. The PVP-coated electrocatalyst shows higher ORR activity under various methanol concentrations in the electrolyte, suggesting that the PVP-coated electrocatalyst has a higher methanol tolerance. Also, the PVP-coated electrocatalyst loses only 14% of the electrochemical surface area after 5000 potential cycles from 0.6–1.0 V versus the reversible hydrogen electrode, indicating better Pt stability than non-coated (27%) and commercial (38%) electrocatalysts due to the unique sandwich structure formed by the PVP and PBI. The power density of the PVP-coated electrocatalyst is four to five times higher compared to non-coated and commercial electrocatalysts with 12 M methanol feeding to the anode side, respectively. PVP coating is important for the enhancement of Pt stability and methanol tolerance. This study offers a new method for preparing a low-cost and high-methanol-tolerant Pt electrocatalyst, and useful information for real DMFC application to eliminate the methanol crossover problem in the cathode side.

Pt–Ru electrocatalysts for fuel cells: developments in the last decade

Reviewed herein are recent advances in the synthesis and performance of Pt–Ru electrocatalysts, including core–shell-like, for anodes in direct methanol fuel cells (DMFC) and in polymer electrolyte fuel cells (PEMFCs) employing reformate gas. Model systems allowing for a better understanding of composition–property and structure–property relationships, in particular of their CO-tolerance and degradation mechanisms, as well as opportunities for innovative syntheses, support optimization, and durability improvements are discussed. Some other new electrocatalysts for DMFC and PEMFC anodes are compared with Pt–Ru systems.

Ultrasmall molybdenum carbide nanocrystals coupled with reduced graphene oxide supported Pt nanoparticles as enhanced synergistic catalyst for methanol oxidation reaction

Ultrasmall molybdenum carbide (MoC) nanocrystals coupled with reduced graphene oxide (RGO) hybrid was successfully synthesized and applied as support for Pt nanoparticles (Pt/MoC-RGO). Compare to the commercial Pt/C, the Pt/MoC-RGO catalyst show remarkable enhanced electrocatalytic activity for methanol oxidation reaction (MOR) in direct methanol fuel cells (DMFCs). The peak current density of Pt/MoC-RGO is 2.4 times of Pt/C. The Pt/MoC-RGO also shows a significant improved CO resistance ability, which likely originates from the abundant Pt-MoC-RGO three-phase interfaces in Pt/MoC-RGO. The long-term stability results show that the electrochemical durability of the Pt/MoC-RGO for MOR is much better than Pt/C, making it a promising next generation electrocatalysts in DMFCs. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) analyses reveal the strong synergetic chemical coupling interaction between the Pt nanoparticles and MoC-RGO, which result in significantly enhanced electrocatalytic activity for MOR.

Hollow PtNi alloy nanospheres with enhanced activity and methanol tolerance for the oxygen reduction reaction

The development of active and methanol-tolerant cathode electrocatalysts for the oxygen reduction reaction (ORR) is extremely important for accelerating the commercial viability of direct methanol fuel cells (DMFCs). In this work, we present an efficient and template-free route for facile synthesis of cyanide (CN−)-functionalized PtNi hollow nanospheres (PtNi@CN HNSs) with a high alloying degree using a simple cyanogel reduction method at room temperature. The physical and electrocatalytic properties of the PtNi@CN HNSs were investigated by various physical and electrochemical techniques. The PtNi@CN HNSs exhibited significantly enhanced electrocatalytic activity, durability, and particular methanol tolerance for the ORR as compared to commercial Pt black, and thus they are promising cathode electrocatalysts for DMFCs.

Pt loaded two-dimensional TaC-nanosheet/graphene hybrid as an efficient and durable electrocatalyst for direct methanol fuel cells

Poor electrocatalytic activity, insufficient operation durability and low carbon monoxide (CO) tolerance of the Pt-based catalysts are key challenges facing the direct methanol fuel cells (DMFCs) as promising electrochemical energy conversion device. We here present a new effort to catalyst designed by depositing Pt nanoparticles on two-dimensional (2D) TaC-nanosheet/graphene hybird (Pt/TaC-G) to obtain notable improvement in electrocatalytic performance over the commercial Pt/C. Experiment results from both X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) support that a strong synergetic chemical coupling interaction between the Pt nanoparticles and the 2D TaC-G significantly enhanced electrocatalytic activity for methanol oxidation reaction (MOR). This process can improve the CO tolerance as well as durability of MOR catalysts simultaneously, making it a promising general approach to design and optimize the next generation electrocatalysts in DMFCs.