scholarly journals Effect of the reductive treatment on the state and electrocatalytic behavior of Pt in catalysts supported on Ti0.8Mo0.2O2-C composite

2021 ◽  
Author(s):  
Cristina Silva ◽  
Irina Borbáth ◽  
Kristóf Zelenka ◽  
István E. Sajó ◽  
György Sáfrán ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Polymer Electrolyte Membrane ◽  
Stripping Voltammetry ◽  
Active Surface ◽  
Active Surface Area ◽  
Structural Investigations ◽  
Electrolyte Membrane ◽  
Metal Support Interaction ◽  
Reductive Treatment ◽  
Enhanced Stability

AbstractTi(1-x)MoxO2-carbon composites are promising new supports for Pt-based electrocatalysts in polymer electrolyte membrane fuel cells offering exciting catalytic properties and enhanced stability against electrocorrosion. Pt and the mixed oxide form a couple liable for strong metal-support interaction (SMSI) phenomenon, generally manifesting itself in decoration of the metal particles by ultrathin layers of the support material upon annealing under reductive conditions. The aim of this work is to evaluate the SMSI phenomenon as a potential strategy for tailoring the properties of the electrocatalyst. A 20 wt% Pt/50 wt% Ti0.8Mo0.2O2-50 wt% C electrocatalyst prepared on Black Pearls 2000 carbon functionalized with HNO3 and glucose was reduced at 250 °C in H2 in order to induce SMSI. The electrocatalytic properties and the stability of the reduced and the original catalysts were analyzed by cyclic voltammetry and COads stripping voltammetry. Structural investigations as well as X-ray photoelectron spectroscopy (XPS) measurements were performed in order to obtain information about the details of the interaction between the oxide and the Pt particles. The electrochemical experiments pointed out a small loss of the electrochemically active surface area of Pt in the reduced catalyst along with enhanced stability with respect to the original one, while structural studies suggested only a minimal decrease of the Pt dispersion. At the same time, hydrogen exposure experiments combined with XPS demonstrated the presence of Mo species directly adsorbed on the Pt surface. Thus, the properties of the reduced catalyst can be traced to decoration of the surface of Pt by Mo-containing species.

Electrocatalytic performance of sonochemically synthesized Pt–Ni/C nanoparticles in fuel cell application

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rajesh Kumar Polagani ◽  
Prashant L. Suryawanshi ◽  
Shirish H. Sonawane ◽  
Mahendra Chinthala
Keyword(s):  
Fuel Cell ◽  
High Performance ◽  
Polymer Electrolyte Membrane ◽  
Pt Nanoparticles ◽  
Active Surface ◽  
Active Surface Area ◽  
Fuel Cell Performance ◽  
Electrolyte Membrane ◽  
Fuel Cell Application ◽  
The Cost

Abstract Developing high-performance electrocatalysts using simple and controllable methods is of interest to reduce the cost of polymer electrolyte membrane fuel cells. In this study, platinum is alloyed with nickel and supported on carbon (Pt–Ni/C) via an ultrasound-assisted route. The crystallite and particle sizes of the obtained nanoparticles were smaller than the commercial carbon-supported Pt nanoparticles. The sonochemically synthesized Pt–Ni/C nanoparticles exhibited superior electrocatalytic properties than the commercial Pt/C nanoparticles in the fuel cell operation. Electrochemical measurements performed with Pt–Ni/C electrocatalyst displayed excellent oxygen reduction and higher electrochemical active surface area (EASA). Optimum fuel cell performance based on peak power density using Pt–Ni/C electrocatalyst was observed as 0.28 W/cm2 at 0.39 V.

scholarly journals Lifetime Prediction of a Polymer Electrolyte Membrane Fuel Cell under Automotive Load Cycling Using a Physically-Based Catalyst Degradation Model

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2054 ◽  
Author(s):  
Manik Mayur ◽  
Mathias Gerard ◽  
Pascal Schott ◽  
Wolfgang Bessler
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Catalyst Layer ◽  
Active Surface ◽  
Temporal Variations ◽  
Multiscale Simulation ◽  
Active Surface Area ◽  
State Variables ◽  
Electrolyte Membrane

One of the bottlenecks hindering the usage of polymer electrolyte membrane fuel cell technology in automotive applications is the highly load-sensitive degradation of the cell components. The cell failure cases reported in the literature show localized cell component degradation, mainly caused by flow-field dependent non-uniform distribution of reactants. The existing methodologies for diagnostics of localized cell failure are either invasive or require sophisticated and expensive apparatus. In this study, with the help of a multiscale simulation framework, a single polymer electrolyte membrane fuel cell (PEMFC) model is exposed to a standardized drive cycle provided by a system model of a fuel cell car. A 2D multiphysics model of the PEMFC is used to investigate catalyst degradation due to spatio-temporal variations in the fuel cell state variables under the highly transient load cycles. A three-step (extraction, oxidation, and dissolution) model of platinum loss in the cathode catalyst layer is used to investigate the cell performance degradation due to the consequent reduction in the electro-chemical active surface area (ECSA). By using a time-upscaling methodology, we present a comparative prediction of cell end-of-life (EOL) under different driving behavior of New European Driving Cycle (NEDC) and Worldwide Harmonized Light Vehicles Test Cycle (WLTC).

Ion Beam Modification of Pt Electrocatalyst Nanoparticles for Polymer Electrolyte Membrane Fuel Cells

2009 ◽  
Vol 1217 ◽  
Author(s):  
Tetsuya Yamaki ◽  
Shunya Yamamoto ◽  
Teruyuki Hakoda ◽  
Hiroshi Koshikawa
Keyword(s):  
Ion Beam ◽  
Polymer Electrolyte Membrane ◽  
Pt Nanoparticles ◽  
Active Surface ◽  
Hydrogen Desorption ◽  
Active Surface Area ◽  
Irradiation Effect ◽  
Energy Beam ◽  
Ion Beam Modification ◽  
Electrolyte Membrane

AbstractPlatinum (Pt) nanoparticles were prepared on a glassy carbon plate by a sputtering method and then irradiated with proton (H+) beams at energies of 0.38 and 10 MeV at room temperature. Cyclic voltammetry in an aqueous 0.5 mol/dm3 H2SO4 solution suggested that the lower-energy beam irradiation enhanced the active surface area of the Pt nanoparticles, calculated from the coulombic charge for hydrogen desorption. Thus, the nanoparticles would be modified by H+ beam-induced electronic excitation so that they have higher surface activity. The mechanism of this irradiation effect seems to be rather complicated and is still unclear at present, but we may discuss it in relation to a change in the interfacial crystal structure during the irradiation.

Stabilization of platinum–nickel alloy nanoparticles with a sulfur-doped graphene support in polymer electrolyte membrane fuel cells

RSC Advances ◽  
2016 ◽  
Vol 6 (113) ◽  
pp. 112226-112231 ◽  
Author(s):  
Calvin Xu ◽  
Md Ariful Hoque ◽  
Gordon Chiu ◽  
Teresa Sung ◽  
Zhongwei Chen
Keyword(s):  
Polymer Electrolyte Membrane ◽  
Active Surface ◽  
Active Surface Area ◽  
Post Heat Treatment ◽  
Half Cell ◽  
Electrolyte Membrane ◽  
Electrochemically Active ◽  
Fuel Cell Cathode ◽  
Doped Graphene ◽  
Electrochemically Active Surface

Post-heat treatment of dealloyed Pt–Ni nanoparticles on sulfur-doped graphene for PEM fuel cell cathode catalysis exhibit greatly improved activity and electrochemically active surface area retention over Pt/C in half-cell conditions.

scholarly journals CO Tolerance and Stability of Graphene and N-Doped Graphene Supported Pt Anode Electrocatalysts for Polymer Electrolyte Membrane Fuel Cells

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 597
Author(s):  
Martin González-Hernández ◽  
Ermete Antolini ◽  
Joelma Perez
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Graphene Nanosheets ◽  
Polymer Electrolyte Membrane ◽  
Co Adsorption ◽  
Active Surface Area ◽  
Pristine Graphene ◽  
Electrolyte Membrane ◽  
Co Tolerance ◽  
Doped Graphene

Pt electrocatalysts supported on pristine graphene nanosheets (GNS) and nitrogen-doped graphene nanoplatelets (N-GNP) were prepared through the ethylene glycol process, and a comparison of their CO tolerance and stability as anode materials in polymer electrolyte membrane fuel cells (PEMFCs) with those of the conventional carbon (C)-supported Pt was made. Repetitive potential cycling in a half cell showed that Pt/GNS catalysts have the highest stability, in terms of the highest sintering resistance (lowest particle growth) and the lowest electrochemically active surface area loss. By tests in PEMFCs, the Pt/N-GNP catalyst showed the highest CO tolerance, while the poisoning resistance of Pt/GNS was lower than that of Pt/C. The higher CO tolerance of Pt/N-GNP than that of Pt/GNS was ascribed to the presence of a defect in graphene, generated by N-doping, decreasing CO adsorption energy.

scholarly journals Sensitive Electrochemical Detection of Caffeic Acid in Wine Based on Fluorine-Doped Graphene Oxide

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1604 ◽  
Author(s):  
Venkatesh Manikandan ◽  
Boopathi Sidhureddy ◽  
Antony Thiruppathi ◽  
Aicheng Chen
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Caffeic Acid ◽  
Photoelectron Spectroscopy ◽  
Limit Of Detection ◽  
Active Surface ◽  
Differential Pulse ◽  
Active Surface Area ◽  
Food And Beverage ◽  
Doped Graphene

We report here a novel electrochemical sensor developed using fluorine-doped graphene oxide (F-GO) for the detection of caffeic acid (CA). The synthesized graphene oxide (GO) and F-GO nanomaterials were systematically characterized with a scanning electron microscope (SEM), and the presence of semi-ionic bonds was confirmed in the F-GO using X-ray photoelectron spectroscopy. The electrochemical behaviours of bare glassy carbon electrode (GCE), F-GO/GCE, and GO/GCE toward the oxidation of CA were studied using cyclic voltammetry (CV), and the results obtained from the CV investigation revealed that F-GO/GCE exhibited the highest electrochemically active surface area and electrocatalytic activity in contrast to the other electrodes. Differential pulse voltammetry (DPV) was employed for the analytical quantitation of CA, and the F-GO/GCE produced a stable oxidation signal over the selected CA concentration range (0.5 to 100.0 μM) with a low limit of detection of 0.018 μM. Furthermore, the acquired results from the selectivity studies revealed a strong anti-interference capability of the F-GO/GCE in the presence of other hydroxycinnamic acids and ascorbic acid. Moreover, the F-GO/GCE offered a good sensitivity, long-term stability, and an excellent reproducibility. The practical application of the electrochemical F-GO sensor was verified using various brands of commercially available wine. The developed electrochemical sensor successfully displayed its ability to directly detect CA in wine samples without pretreatment, making it a promising candidate for food and beverage quality control.

scholarly journals On the Influence of Composition and Structure of Carbon-Supported Pt-SnO2 Hetero-Clusters onto Their Electrocatalytic Activity and Durability in PEMFC

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 803 ◽  
Author(s):  
Spasov ◽  
Ivanova ◽  
Pushkarev ◽  
Pushkareva ◽  
Presnyakova ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Photoelectron Spectroscopy ◽  
Layer Structure ◽  
Polymer Electrolyte Membrane ◽  
Carbon Support ◽  
Reduction Reaction ◽  
Support Surface ◽  
Catalytic Layer ◽  
X Ray ◽  
Electrolyte Membrane

A detailed study of the structure, morphology and electrochemical properties of Pt/C and Pt/x-SnO2/C catalysts synthesized using a polyol method has been provided. A series of catalysts supported on the SnO2-modified carbon was synthesized and studied by various methods including transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical methods, and fuel cell testing. The SnO2 content varies from 5 to 40 wt %. The TEM images, XRD and XPS analysis suggested the Pt-SnO2 hetero-clusters formation. The SnO2 content of ca. 10% ensures an optimal catalytic layer structure and morphology providing uniform distribution of Pt-SnO2 clusters over the carbon support surface. Pt/10wt %-SnO2/C catalyst demonstrates increased activity and durability toward the oxygen reduction reaction (ORR) in course of accelerated stress testing due to the high stability of SnO2 and its interaction with Pt. The polymer electrolyte membrane fuel cell current–voltage performance of the Pt/10wt %-SnO2/C is comparable with those of Pt/C, however, higher durability is expected.

Flowerlike submicrometer gold particles: Size- and surface roughness-controlled synthesis and electrochemical characterization

2010 ◽  
Vol 25 (9) ◽  
pp. 1755-1760 ◽  
Author(s):  
Changsheng Shan ◽  
Dongxue Han ◽  
Jiangfeng Song ◽  
Ari Ivaska ◽  
Li Niu
Keyword(s):  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Electrocatalytic Activity ◽  
Active Surface ◽  
Molar Ratio ◽  
Active Surface Area ◽  
Step Method ◽  
Gold Particles ◽  
X Ray ◽  
One Step

Flowerlike submicrometer gold particles were synthesized through a simple one-step method using p-diaminobenzene as a reductant in the presence of poly(sodium 4-styrenesulfonate) in aqueous solution. The particle size with diameters ranging from 267 to 725 nm could be tuned by varying the molar ratio of poly(sodium 4-styrenesulfonate) to HAuCl4, which also resulted in tunable roughness. The gold particles were confirmed by scanning electron microscopy, energy dispersive x-ray spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. Cyclic voltammetry showed that the specific surface area of the flowerlike particles was larger than that of sphere particles. The obtained flowerlike particles with higher surface area also exhibited higher electrocatalytic activity toward H2O2 and O2. The increase of electrocatalytic activity could be attributed to the increase of the active surface area.

scholarly journals Voltammetric Determination of Amoxicillin Using a Reduced Graphite Oxide Nanosheet Electrode

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Thi Hai Yen Pham ◽  
Thi Trang Mai ◽  
Hoang Anh Nguyen ◽  
Thi Thu Hien Chu ◽  
Thi Thu Ha Vu ◽  
...  
Keyword(s):  
Graphite Oxide ◽  
Graphite Electrode ◽  
Limit Of Detection ◽  
Reduction Process ◽  
Stripping Voltammetry ◽  
Active Surface ◽  
Active Surface Area ◽  
Accumulation Time ◽  
Reduced Graphite Oxide

A reduced graphite oxide nanosheet electrode (RGOnS) was prepared as a sensor for amoxicillin (AMX) detection, an antibiotic commonly used in the livestock farm, by the square-wave adsorptive stripping voltammetry technique. Graphite oxide with nanosheet shape was produced from a graphite electrode by a chronoamperometry process at 5 V and then an electrochemical reduction process was carried out to form RGOnS with restored long-range conjugated networks and better conductivity. The electrodes were characterized by SEM, EDX, and FTIR spectroscopy. The RGOnS electrode prepared at an optimal reduction potential of −1 V for 120 s exhibits a larger electrochemical active surface area, and the obtained oxidation signal of AMX is approximately ten times higher than that of the pristine graphite electrode. The analytical conditions such as the pH of electrolyte and accumulation time were optimized. The calibration curve built under the optimal conditions provided a good linear relationship in the range of AMX concentration from 0.5–80 µM with the correlation coefficient of 0.9992. The limit of detection was calculated as 0.193 µM. Satisfactory results are obtained from the detection of the AMX in different samples using the prepared electrode.

Sign in / Sign up

Export Citation Format

Share Document