scholarly journals Preparation of Pt electrocatalyst supported by novel, Ti(1−x)MoxO2-C type of composites containing multi-layer graphene

2021 ◽  
Author(s):  
Ilgar Ayyubov ◽  
Adriana Vulcu ◽  
Camelia Berghian-Grosan ◽  
Emília Tálas ◽  
Irina Borbáth ◽  
...  
Keyword(s):  
Ball Milling ◽  
Polymer Electrolyte Membrane ◽  
Sol Gel ◽  
Stripping Voltammetry ◽  
Rutile Phase ◽  
Stability Test ◽  
Electrolyte Membrane ◽  
Co Tolerance ◽  
Layer Graphene ◽  
Before And After

AbstractBall milling is a relative simple and promising technique for preparation of inorganic oxide–carbon type of composites. Novel TiO2-C and Ti0.8Mo2O2-C type of composites containing multi-layer graphene were prepared by ball milling of graphite in order to get electrocatalyst supports for polymer electrolyte membrane fuel cells. Starting rutile TiO2 was obtained from P25 by heat treatment. Carbon-free Ti0.8Mo2O2 mixed oxide, prepared using our previously developed multistep sol–gel method, does not meet the requirements for materials of electrocatalyst support, therefore parent composites with Ti0.8Mo2O2/C = 75/25, 90/10 and 95/5 mass ratio were prepared using Black Pearls 2000. XRD study of parent composites proved that the oxide part existed in rutile phase which is prerequisite of the incorporation of oxophilic metals providing CO tolerance for the electrocatalyst. Ball milling of TiO2 or parent composites with graphite resulted in catalyst supports with enhanced carbon content and with appropriate specific surface areas. XRD and Raman spectroscopic measurements indicated the changes of graphite during the ball milling procedure while the oxide part remained intact. TEM images proved that platinum existed in the form of highly dispersed nanoparticles on the surface of both the Mo-free and of Mo-containing electrocatalyst. Electrocatalytic performance of the catalysts loaded with 20 wt% Pt was studied by cyclic voltammetry, COads-stripping voltammetry done before and after the 500-cycle stability test, as well as by the long-term stability test involving 10,000 polarization cycles. Enhanced CO tolerance and slightly lower stability comparing to Pt/TiO2-C was demonstrated for Pt/Ti0.8Mo2O2-C catalysts.

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 Highly CO tolerant PtRu/PtNi/C catalyst for polymer electrolyte membrane fuel cell

RSC Advances ◽  
2017 ◽  
Vol 7 (14) ◽  
pp. 8453-8459 ◽  
Author(s):  
Qi Wang ◽  
Guoxiong Wang ◽  
Hualong Tao ◽  
Zhiqiang Li ◽  
Lei Han
Keyword(s):  
Fuel Cell ◽  
Synergistic Effect ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Electrolyte Membrane ◽  
Co Tolerance

A PtRu/PtNi/C catalyst shows higher CO tolerance than PtNi/C, PtNi–Ru/C and PtRu/C catalysts due to the synergistic effect between the PtRu surface and PtNi core.

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.

scholarly journals Electrochemical Analysis for Demonstrating CO Tolerance of Catalysts in Polymer Electrolyte Membrane Fuel Cells

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1425 ◽  
Author(s):  
Min ◽  
Jeffery ◽  
Kim ◽  
Jung
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Hydrogen Oxidation ◽  
Polymer Electrolyte Membrane ◽  
Co Adsorption ◽  
Electrochemical Analysis ◽  
Hydrogen Oxidation Reaction ◽  
Test Protocol ◽  
Electrolyte Membrane ◽  
Co Tolerance

Since trace amounts of CO in H2 gas produced by steam reforming of methane causes severe poisoning of Pt-based catalysts in polymer electrolyte membrane fuel cells (PEMFCs), research has been mainly devoted to exploring CO-tolerant catalysts. To test the electrochemical property of CO-tolerant catalysts, chronoamperometry is widely used under a CO/H2 mixture gas atmosphere as an essential method. However, in most cases of catalysts with high CO tolerance, the conventional chronoamperometry has difficulty in showing the apparent performance difference. In this study, we propose a facile and precise test protocol to evaluate the CO tolerance via a combination of short-term chronoamperometry and a hydrogen oxidation reaction (HOR) test. The degree of CO poisoning is systematically controlled by changing the CO adsorption time. The HOR polarization curve is then measured and compared with that measured without CO adsorption. When the electrochemical properties of PtRu alloy catalysts with different atomic ratios of Pt to Ru are investigated, contrary to conventional chronoamperometry, these catalysts exhibit significant differences in their CO tolerance at certain CO adsorption times. The present work will facilitate the development of catalysts with extremely high CO tolerance and provide insights into the improvement of electrochemical methods.

Synthesis and Properties of Composite Membranes for Polymer Electrolyte Membrane Fuel Cells

2014 ◽  
Vol 884-885 ◽  
pp. 251-256 ◽  
Author(s):  
Alexandra N. Chesnokova ◽  
Oksana V. Lebedeva ◽  
Yury N. Pozhidaev ◽  
Nikolay A. Ivanov ◽  
Alexander E. Rzhechitskii
Keyword(s):  
Polymer Electrolyte Membrane ◽  
Sol Gel ◽  
Glycidyl Ether ◽  
Composite Membranes ◽  
Exchange Capacity ◽  
Conductivity Activation Energy ◽  
Ion Exchange Capacity ◽  
Electrolyte Membrane ◽  
Sol Gel Synthesis ◽  
Derivatives Of

The paper is devoted to the sol-gel synthesis of proton conductive organic-silicon composite membranes based on tetraethyl orthosilicate (TEOS) and copolymers of 2-methyl-5-vinylpyridine and vinyl chloride (MVP-VC), 2-methyl-5-vinylpyridine and vinyl acetate (MVP-VA), copolymers of ethylene glycol vinyl glycidyl ether and styrene (KS-1 and KS-2), and nitrogen-containing heteroaromatic derivatives of sulfonic acids: 2-phenyl-5-benzimidazolsulfonic acid (PBISA) and pyridine-3-sulfonic acid (PSA). Properties of synthesized membranes, such as proton conductivity, activation energy, ion exchange capacity, dimensional stability have been investigated.

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