Low Platinum Catalyst Research Articles

Efficient catalysis for acidic methanol oxidation: Exploration of a Low-Platinum quaternary alloy catalyst via a Two-Step method

The quest for platinum-based catalysts with enhanced catalytic efficacy and durability during the methanol oxidation reaction (MOR) has been a focal point in energy conversion science. Traditional platinum-based catalysts are often constrained by their high platinum content, which escalates economic costs and complicates experimental protocols. In this study, we introduce a low-platinum-loaded catalyst synthesized via a two-step method, which incorporates a four-component alloy. This innovative approach significantly reduces platinum content while maintaining superior catalytic performance through precise control over the alloy’s composition and structure. The two-step synthesis methodology streamlines the conventional multi-step processes, enhancing the catalyst preparation’s efficiency and reproducibility. The resulting PtCoSnCu/N-C alloy catalyst exhibits remarkable catalytic activity in methanol solution, with mass activity and specific activity that are 9.73 and 9.75 times higher, respectively, than those of commercial platinum on carbon (Pt/C) catalysts. Notably, the optimized PtCoSnCu/N-C alloy catalyst demonstrates exceptional long-term stability, outperforming Pt/C in aging and extended stability tests. Density functional theory (DFT) calculations elucidate the optimization of the electronic structure and the synergistic effect of surface atoms in the PtCoSnCu/N-C catalyst, which mitigates the adsorption energy of CO molecules and enhances the utilization rate of active sites during the oxidation process. This research presents a paradigm-shifting low-platinum catalyst strategy for methanol fuel cells, establishing a theoretical foundation for catalyst design and optimization.

Precisely tuning the Ni3N/Pt interface to boost the catalytic activity of alkaline hydrogen evolution reaction

The hydrogen evolution reaction (HER) in alkaline solutions does not access H* directly, resulting in a slower reaction kinetics compared to that in acidic solutions. Here, we report a Cr-doped Ni3N/Pt heterostructure that provides additional active sites to produce H* via the water-cleaving step, in addition to the intrinsic active Pt site for H* absorption. It is demonstrated that the Cr dopant can modulate the charge redistribution between Ni3N and Pt interface, lowering the energy barrier of both the Volmer step and the following Heyrovsky step. As a result, the prepared Cr-Ni3N/Pt catalyst achieves an extreme low overpotential of 20 mV to deliver a current density of 10 mA/cm2 under alkaline conditions, which is significantly better than the commercial Pt/C catalyst (45 mV). Density Functional Theory (DFT) further reveals that the Cr-modified Ni3N/Pt interface undergoes electronic orbital hybridization, enhancing the water adsorption and dissociation processes on the Ni sites. This work presents the feasibility of the electronic structure modulation in low-platinum catalysts, which provides an effective strategy for the design of electrocatalysts used in multi-step reactions.

Performance and Durability of Carbon-Free Ionomer-Free PEFC Cathode Using Pt Nanosheet Catalyst

Polymer electrolyte fuel cells (PEFCs) have been attracting attention as highly efficient power sources and have been commercialized for use in residential power plants and automobiles. However, further widespread adoption requires the development of low-platinum catalysts. Additionally, for installation in heavy duty vehicles such as large trucks, high durability at high temperatures is necessary. Pt nanosheets (Pt(ns)), consisting of several atomic layers of Pt with a flat structure, possess high mass activity and durability due to the high specific surface area and low surface energy [1]. Conventional PEFC electrodes consisting of carbon-supported platinum (Pt/C) catalyst and ionomer suffer from degradation due to dissolution/redeposition, Ostwald ripening, and agglomeration of Pt, corrosion of the carbon support, and Pt poisoning by ionomer. Therefore, using unsupported Pt(ns) for an electrode that consists of neither carbon nor ionomer is expected to eliminate the degradation factors, resulting in a highly active and durable electrode. The purpose of this study is to develop highly active and durable electrodes by using Pt(ns) and eliminating degradation factors by making them carbon-free and ionomer-free.Polycrystalline Pt(ns) was synthesized by interlayer oxidation of graphene, as described elsewhere [2]. Catalyst ink was prepared, and cathode catalyst layers were created by dropping or spraying it onto carbon paper. A membrane-electrode assembly (MEA) was made by hot-pressing the cathode catalyst layer together with an anode made of Pt/C onto an electrolyte membrane. Power generation was conducted at 80˚C by supplying H2 to the anode and O2 or air to the cathode, each humidified under ambient pressure. Durability was evaluated by repeatedly applying cyclic potentials between 1.0 V and 1.5 V, supplying N2 to the anode and cathode, and examining changes in the cyclic voltammogram.The I-V curves of MEAs with ionomer-free carbon-free Pt(ns) cathodes fabricated using drop-coating and spray-coating methods and measured using air and oxygen as the cathode supply gases are shown in Fig. 1. As demonstrated in the figure, the activation overpotential at low current density was high, suggesting a low Pt utilization. The shape of the I-V curve of MEA using the spray method at high current density indicated that the concentration overpotential was suppressed under oxygen conditions but was high under air conditions. On the other hand, the concentration overpotential of the MEA using the drop method was high even under oxygen conditions. This may be attributed to the small spaces between the restacked nanosheets, which inhibited diffusion.A start-stop simulated potential cycle test was conducted for the MEA using ionomer-free carbon-free Pt(ns) cathode. The CV curves measured after a certain number of cycles are shown in Fig. 2. As shown in the figure, the change in the shape of the CV was small, and the ECSA remaining rate of the electrode was above 80% even after 8000 cycles, whereas that of the Pt/C cathode was less than 50% after 4000 cycles. This suggests that carbon-free ionomer-free Pt(ns) electrode has the potential as highly durable low Pt electrodes.AcknowledgementPart of this paper is based on results obtained from a project, JPNP20003, subsidized by the New Energy and Industrial Technology Development Organization (NEDO).

(Digital Presentation) An Efficient and Stable of Low-Pt Catalysts for Full Water Splitting in Acidic

Designing efficient platinum-based catalysts is of great interest for the lowering of Pt dosage and the enhance of catalytic activity on the full water splitting. However, it is still challenging to develop low-Pt catalysts with evenly distributed, proper sized particles on supports. Here, Metal-Organic Frameworks (MOF) derivatives were used as supports to prepare ultra-low platinum catalysts of uniform particle size. MOF derived transition metal heteroatom-doped carbon is a promising support for precious metal nanoparticles of electrocatalytic activity, because it provides abundant anchor points that enhance their adhesion, transition metals on the MOF skeleton can effectively prevent further growth of platinum particles, more importantly, through the proof-metal electron interaction, improve their intrinsic catalytic activity to achieve high activity and stable hydrogen evolution reaction. We will characterize the characteristics of the catalyst from several aspects, such as morphology, pore size and composition. Finally, we will verify the catalytic ability, rate ability and stability of low platinum catalyst with MOF derivatives support, through a comprehensive characterization of the catalyst HER and OER performance.

Pt Nanoparticles Supported on Iron and Nitrogen-Doped Holey Graphene for Boosting ORR Performance

Developing low-platinum catalysts is considered a promising strategy to facilitate the commercialization of fuel cells. However, the electrochemical performance of such materials is often hindered by mass-transfer issues. In this study, platinum nanoparticles supported on iron and nitrogen-doped holey graphene (Pt/Fe, N-HG) were synthesized by a simple method and used as an oxygen reduction reaction (ORR) catalyst. The unique holey structure and the co-doping of Fe and N atoms are proved beneficial for not only the formation of Pt nanoparticles but also enhancing the electrochemical performance of the catalyst. Density functional theory calculations indicate that the co-doping of Fe and N atoms increases the ability to adsorb Pt, as well as enhances the Pt adsorption of O2 and oxygen-containing intermediates in the ORR. This study presents a novel approach for the controllable synthesis of multidoped holey graphene-based electrocatalysts, with optimized surface holey structures and electrochemical performances. These findings offer significant insights into the development of efficient catalysts for fuel cell applications.

Small-size MOF derived highly active low-platinum catalysts for oxygen reduction reactions

Platinum catalysts derived from MOF have shown excellent potential in oxygen reduction reaction (ORR) of fuel cells. In this paper, we applied a simple and efficient synthesis method to prepare ZIF-67-Rx(x ​= ​0–4) with different sizes. Co@MOF-Rx(x ​= ​0–4) skeleton supports with carbon nanotube structure were obtained by further pyrolysis. Pt/Co@MOF-Rx(x ​= ​0–4) catalysts were synthesized by loading Co@MOF-Rx with 10% Pt. By changing the content of metal precursor, the nanometer size of ZIF-67-Rx was reduced from 722 ​nm to 93 ​nm. Pt/Co@MOF-Rx showed super high oxygen reduction activity and superior cycle stability. At 0.9 ​V, the mass activity(MA) and specific activity(SA) were 9.63 ​mA mgPt−1and 1.33 ​mA ​cm2, respectively, which were 1.54 and 1.23 times higher than those of Pt/C(20%). After 6000 cycles, it shows excellent stability than Pt/C(20%). This work brings new opportunities to design and prepare promising catalyst supports for proton exchange membrane fuel cells.

Preparation and Electrochemical Performance of a Graphene Cathode Catalyst Decorated With Pt by Prolysis

For fuel cells, to produce high-quality and low-platinum catalyst is a pressing technical problem. In this study, graphene cathode catalysts with controllable platinum content were decorated by pyrolyzing chloroplatinic acid under various process parameters to obtain a high catalytic activity and durability. The results show that platinum particles generated by pyrolyzing chloroplatinic acid are uniformly loaded on graphene without agglomeration. The average particle size of platinum particles is about 2.12 nm. The oxygen reduction reaction catalytic activity of catalyst samples first increases, then decreases with increasing platinum loading in cyclic voltammetry and LSV. Compared with the commercial Pt/C (20 wt% Pt) catalyst, the initial potential and the current density retention rate of the catalyst decorated with 8% platinum are 55 mV and 23.7% higher, respectively. From i-t curves, it was found that the stability of the catalyst prepared in this paper was improved compared with the commercial Pt/C catalyst. The catalysts prepared in the present research exhibits superior catalytic activity and stability.

Synthesis of ZIF-69-derived Electrocatalyst with Low loading Platinum for Oxygen Reduction Reaction

Here, we report a facile preparation of a low-platinum catalyst derived from ZIF-69 denoted as Pt@ZC-69. Nitrogen-abundant ZIF-69 could act as a support to efficiently encapsulate trimethyl (methylcyclopentadienyl) platinum (IV) (MeCpPtMe3@ZIF-69) precursor. After high-temperature reduction, Pt@ZC-69 with uniform Pt-loading was obtained. In the acidic medium, the Pt@ZC-69 presented a desirable performance, the half-wave potential could reach 0.845 V vs. RHE, while the Pt content is less than 10% of the commercial 20 wt.% Pt/C. Moreover, Pt@ZC-69 also possessed robust stability (40 mV decays after 20000 cycles).

Intermetallic Co-Pt/C Nanoparticles Synthesized Via Sonochemical Method As Enhanced Electrocatalysts for Cathode of PEMFC

For fuel cell stack of 80 kW, platinum for electrocatalyst requires around 10 g per fuel cell electric vehicle (FCEV). A large-scale synthesis method for the low-platinum catalyst is necessary for this field to reduce man-power. Ultrasound-assisted polyol synthesis (UPS) is a method for the preparation of small and uniform size transition metal core-platinum shell nanoparticles evenly distributed on the support. Platinum(Ⅱ) acetylacetonate, Cobalt(Ⅱ) acetylacetonate, and carbon support were dispersed in ethylene glycol which is reducing agent and irradiated by ultrasound for 3 h to reduce the precursor to metal nanoparticles, followed by washing and drying to obtain a powder. The characterization was observed by solution color visualization, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and electrocatalytic performance. Also, the synthesized samples were calcined at various temperatures to cause the atomic rearrangement to the most stable arrangement, and atomic accumulation of boundary between each atom and compression of platinum lattice that affects activity or durability of electrocatalyst has changed. Synthesized sample with optimized synthesis and treatment condition shows improved electrochemically active surface area (ECSA) and Oxygen reduction reaction (ORR) catalytic activity in the half-cell test and durable catalytic activity in the performance evaluation of membrane-electrode assembly (MEA) compared to existing Platinum catalyst. As renewable energy conversion and storage system is one of the main challenges, FCEV is developed to solve pollution from CO2 emission and oil depletion issues. Our low-platinum nanoparticle with uniform distribution synthesized using a sonochemical method will replace precious metal catalysts used in fuel cells instead of platinum catalysts.

Low-platinum catalyst based on sulfur doped graphene for methanol oxidation in alkaline media

A novel two-step, low-temperature method was employed for the synthesis of a catalyst with small platinum content (2 wt%) based on sulfur doped reduced graphene oxide (S-RGO-Pt). Morphology and chemical composition of the hybrid material were investigated by several methods: X-ray powder diffraction (XRD), transmission and scanning electrode microscopy (TEM, SEM), elemental analysis, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The electrocatalytic performance of the prepared hybrid material was investigated in 1M CH3OH/1M NaOH using a modified glassy carbon electrode (GC_S-RGO-Pt). The results showed excellent electrocatalytic activity and stability toward methanol oxidation in alkaline media (50.4% activity retained after 500 cycles and 8.4% after 1000 cycles) compared to commercial platinum 10 wt% on carbon (Pt/C) material (8.09% activity retained after 500 cycles). The catalyst tolerance to CO poisoning intermediates was evaluated using CO stripping voltammetry and the ratio of forward and backward peak current density (If/Ib). The If/Ib ratio calculated for S-RGO-Pt is 15, while for Pt/C is 9.6, which clearly demonstrates that the prepared hybrid material is significantly more efficient than commercial Pt/C, even if the platinum content is only 2 wt%. The rotating disk electrode (RDE) technique was employed to study the kinetic aspects of methanol oxidation reaction in alkaline media. To follow the transformations occurred at the electrodes' surfaces after the electrochemical treatment, the Raman spectroscopy and Machine Learning (ML) algorithms were used; the results also indicated a greater stability of the S-RGO-Pt composite for Methanol oxidation reaction (MOR) in alkaline media.

Direct preparation of core-shell platinum cathode in membrane electrode assembly catalyst layer for polymer electrolyte fuel cell

Core–shell catalyst has been attracting attention as a low-Pt catalyst for PEFC cathode. However, its mass production method has not yet been established. In this paper, a novel method suitable for continuous production of low-platinum catalyst layer for PEFC is proposed. Catalyst layer of carbon-supported Pd@Pt core–shell catalyst (Pd@Pt/C) is fabricated by using Cu underpotential deposition (UPD) followed by surface-limited redox replacement (SLRR) directly to the porous catalyst layer made of Pd core (Pd/C). The distribution of Pt corresponded well with that of Pd throughout the catalyst layer, indicating that the core–shell reaction occurs in the entire catalyst layer. Pd@Pt/C shows 1.8 times higher mass activity than Pt/C, which is comparable to Pd@Pt/C prepared by conventional microgram-scale method.

Novel Preparation Method of Core-Shell Platinum Cathode for PEFC Using UPD Directly to Catalyst Layer

Polymer electrolyte fuel cell (PEFC) is beginning to be put into practical use due to its high efficiency. However, reduction of cost is necessary for the further spread of PEFC. Generally, platinum is used for the catalyst of PEFC electrode. Since platinum is scarce and expensive, it is required to reduce the amount of Pt in the catalyst. Core-shell catalyst using Cu-UPD (under potential deposition) followed by SLRR (surface limited redox replacement) has been developed as a low-platinum catalyst [1]. In order to use this catalyst for practical PEFC, preparation method suitable for mass production has been studied [2]. In this research, we propose a novel preparation method of core-shell catalyst by directly using Cu-UPD to the catalyst layer of core material. This method is expected to enable continuous production of Pt core-shell catalyst layer. Since this process treats catalyst layer of which the thickness is several tens of micrometers, it is necessary to consider factors different from conventional method, especially mass transfer. In this study, Pd@Pt/C catalyst layer was prepared by using Cu-UPD and SLRR directly to the catalyst layer of Pd/C, and the physical properties and the performance was evaluated. Pd/C (30.7 wt%-Pd, Ishifuku Kogyo Co., Ltd.) was used as core material. The catalyst ink was prepared by mixing Pd/C with distilled water, 1-propanol, and Nafion® solution. The ink was coated on a carbon paper (CP) with a microporous layer (MPL). The fabricated catalyst layer was immersed in deaerated 0.5 M H2SO4 solution. After cleaning the electrode by CV, the catalyst layer was immersed in 50 mM CuSO4 + 0.5 M H2SO4 solution, and Cu was deposited on Pd particles by chronoamperometry (CA) at 0.1 V versus Ag/AgCl for 30 minutes. The catalyst layer was then immersed in 5 mM K2PtCl4 + 0.5 M H2SO4 solution to obtain Pd@Pt/C catalyst layer. This process was repeated for 1-3 times. The obtained catalyst layer and Pt/C carbon paper were hot-pressed onto each side of the Nafion membrane to fabricate MEA. Terminal voltage vs. current density of the MEA was measured at 80˚C. IR-free polarization curves of MEA using Pd@Pt/C catalyst layer (0.04 mg-Pt/cm2) and MEA using Pt/C (0.30 mg-Pt/cm2) are shown in Fig. 1. Since the loading amount of Pt was not the same, mass activity of each MEA calculated from the current density at the IR-free terminal voltage of 800 mV are shown in Table 1. The mass activity of Pd@Pt/C 2SLRR was 1.8 times higher than that of Pt/C. This result is similar to the mass activity reported by Inaba et al. for MEA using Pd @Pt/C prepared by “modified Cu-UPD method”. Therefore, it is considered that this novel method is effective to produce core-shell catalyst layers with performance comparable to that prepared by the conventional method. Acknowledgement This work was supported by New Energy and Industrial Technology Development Organization (NEDO), Japan. References J. Zhang, et al., Angew. Chem., Int. Ed., 44, 2132 (2005)M. Inaba, et al., J. Jpn. Petrol. Inst., 58, 55 (2015) Figure 1

Contamination of Low Platinum Catalyst Loading Cathodes for Proton Exchange Membrane Fuel Cells

Fuel cell vehicles have recently entered the market place (1). Future increases in technology adoption are dependent on concurrent cost reduction and improved durability (2). This is a major challenge because membrane/electrode assemblies based on low platinum catalyst loadings have shown inferior durability (3). Many processes limit the proton exchange membrane fuel cell (PEMFC) durability including the presence of contaminants in ambient air. Although a filter is added at the air intake to remove particulates and undesirable gaseous species, contaminant slippage, missed replacements after the filter has reached its end of life and other failures increase fuel cell exposure risks. A strategy relying on the understanding of contamination mechanisms is expected to result in a more robust system with the development of mitigation, recovery and maintenance procedures that supplement the air filter. Such a strategy is necessary because the impact of many contaminants is still unknown (4). Furthermore, relatively little contaminant related information is available for low platinum catalyst loadings (5-7). In this tutorial, focus will be given to recent contamination results and fundamental understanding obtained with a low cathode platinum loading of 0.1 mg cm-2, a value consistent with the United States Department of Energy 2020 target of 0.125 mg cm-2 for the sum of anode and cathode catalyst loadings. All tested contaminants are organic and representative of alcohols (iso-propanol), alkenes (propene), alkynes (acetylene), esters (methyl methacrylate), halocarbons (bromomethane), nitriles (acetonitrile), and polycyclic aromatics (naphthalene). The impact of catalyst loading and contaminant on cell performance, contaminant hydrophobicity on liquid water transport, a long duration contaminant exposure on degradation, a fuel cell stack compatible recovery procedure on cell voltage losses sustained during contamination, and a contaminant mixture on the synergy between species and cell performance will be discussed and contextualized with the relevant literature. All these contamination aspects have either not been explored or been insufficiently documented. Acknowledgments Authors are grateful to the Office of Naval Research (award N00014-13-1-0463), the Department of Energy (award DE-EE0000467), the National Institute of Standards and Technology (neutron imaging beam time), and the Hawaiian Electric Company for their ongoing support to the operations of the Hawaii Sustainable Energy Research Facility.

Platinum-decorated palladium-nanoflowers as high efficient low platinum catalyst towards oxygen reduction

A three-dimensional, low platinum (Pt) catalyst was prepared by decorating platinum on the palladium nanoflowers (PdNF) by an underpotential deposition (UPD) method. The PdNF was synthesized by a solvothermal approach, using oleic acid as the template and benzyl alcohol as the solvent-reducing agent. The obtained Pd with a morphology of uniform nanoflowers is composed of plentiful nanosheets. After decorating with platinum, the catalyst PdNF@Pt exhibits much higher activity for the oxygen reduction reaction (ORR) compared to commercial Pt/C (Pt 20 wt%). The interaction between deposited Pt and PdNF was revealed by XPS analysis, and the high performance of the PdNF@Pt catalyst was attributed to following two aspects: the increased of dispersion of platinum based on PdNF substrate, and the increased intrinsic activity of the active sites caused by the interaction of Pt and Pd NF.

Pt-nanoflower as high performance electrocatalyst for fuel cell vehicle

The development of low platinum catalysts for automotive fuel cells is a way to solve platinum resource constraints. We successfully prepared Pt-nanoflower supported on carbon black in aqueous solution with the aid of Cetyltrimethyl Ammonium Bromide (CTAB). Those nanoflowers showed uniform particle size distribution with average particle size of 27.0 nm. XRD indicated lattice compression for Pt from as-synthesized Pt/C. 71.6% of Pt existed in the form of elementary substance based on XPS. All those assembly nanostructure contributed to remarkable area-specific and mass-specific activities in oxygen reduction reaction.

Is kinematic analysis useful as a clinical test during whiplash associated disorders recovery? A clinical study

The development of low platinum catalysts for automotive fuel cells is a way to solve platinum resource constraints. We successfully prepared Pt-nanoflower supported on carbon black in aqueous solution with the aid of Cetyltrimethyl Ammonium Bromide (CTAB). Those nanoflowers showed uniform particle size distribution with average particle size of 27.0 nm. XRD indicated lattice compression for Pt from as-synthesized Pt/C. 71.6% of Pt existed in the form of elementary substance based on XPS. All those assembly nanostructure contributed to remarkable area-specific and mass-specific activities in oxygen reduction reaction.

High-Performance Core–Shell Catalyst with Nitride Nanoparticles as a Core: Well-Defined Titanium Copper Nitride Coated with an Atomic Pt Layer for the Oxygen Reduction Reaction

A class of core–shell structured low-platinum catalysts with well-dispersed inexpensive titanium copper nitride nanoparticles as cores and atomic platinum layers as shells exhibiting high activity and stability for the oxygen reduction reaction is successfully developed. Using nitrided carbon nanotubes (NCNTs) as the support greatly improved the morphology and dispersion of the nitride nanoparticles, resulting in significant enhancement of the performance of the catalyst. The optimized catalyst, Ti0.9Cu0.1N@Pt/NCNTs, has a Pt mass activity 5 times higher than that of commercial Pt/C, comparable to that of core–shell catalysts with precious metal nanoparticles as the core, and much higher than that the latter if we take into account the mass activity of all platinum group metals. Furthermore, only a minimal loss of activity can be observed after 10000 potential cycles, demonstrating the catalyst’s high stability. Atomic-scale elemental mapping confirmed that the core–shell structure of the catalyst remaine...

A Comparative Study on Ternary Low-Platinum Catalysts with Various Constructions for Oxygen Reduction and Methanol Oxidation Reactions

Three types of ternary low-platinum nanocatalysts, alloy PdPtIr/C, core–shell PdPt@PtIr/C and Pd@PtIr/C, have been prepared, and their catalytic behaviors toward methanol oxidation reaction (MOR)/oxygen reduction reaction (ORR) are comparatively investigated via cyclic voltammetry and chronoamperometry analysis in an acidic medium. Through a two-step colloidal technique, the synthesized core–shell structured catalyst PtPd@PtIr/C with alloy core and alloy shell show the best catalytic activity toward MOR and the best poisoning tolerance. The alloy PdPtIr/C catalyst prepared via a one-step colloidal technique exhibits the best performance toward ORR among the three catalysts. All the three catalysts are characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and other characterization techniques.

Recent Advances in Carbon Supported Metal Nanoparticles Preparation for Oxygen Reduction Reaction in Low Temperature Fuel Cells

The oxygen reduction reaction (ORR) is the oldest studied and most challenging of the electrochemical reactions. Due to its sluggish kinetics, ORR became the major contemporary technological hurdle for electrochemists, as it hampers the commercialization of fuel cell (FC) technologies. Downsizing the metal particles to nanoscale introduces unexpected fundamental modifications compared to the corresponding bulk state. To address these fundamental issues, various synthetic routes have been developed in order to provide more versatile carbon-supported low platinum catalysts. Consequently, the approach of using nanocatalysts may overcome the drawbacks encountered in massive materials for energy conversion. This review paper aims at summarizing the recent important advances in carbon-supported metal nanoparticles preparation from colloidal methods (microemulsion, polyol, impregnation, Bromide Anion Exchange…) as cathode material in low temperature FCs. Special attention is devoted to the correlation of the structure of the nanoparticles and their catalytic properties. The influence of the synthesis method on the electrochemical properties of the resulting catalysts is also discussed. Emphasis on analyzing data from theoretical models to address the intrinsic and specific electrocatalytic properties, depending on the synthetic method, is incorporated throughout. The synthesis process-nanomaterials structure-catalytic activity relationships highlighted herein, provide ample new rational, convenient and straightforward strategies and guidelines toward more effective nanomaterials design for energy conversion.

Development of Low-platinum Catalyst for Fuel Cells by Mechano-chemical Method

Development of Low-platinum Catalyst for Fuel Cells by Mechano-chemical Method