scholarly journals Universal dependence of hydrogen oxidation and evolution reaction activity of platinum-group metals on pH and hydrogen binding energy

2016 ◽  
Vol 2 (3) ◽  
pp. e1501602 ◽  
Author(s):  
Jie Zheng ◽  
Wenchao Sheng ◽  
Zhongbin Zhuang ◽  
Bingjun Xu ◽  
Yushan Yan
Keyword(s):  
Binding Energy ◽  
Hydrogen Oxidation ◽  
Ph Dependence ◽  
Platinum Group Metals ◽  
Hydrogen Binding ◽  
Hydrogen Oxidation Reaction ◽  
Promoting Effect ◽  
Onset Potential ◽  
Co Stripping ◽  
Platinum Group

Understanding how pH affects the activity of hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) is key to developing active, stable, and affordable HOR/HER catalysts for hydroxide exchange membrane fuel cells and electrolyzers. A common linear correlation between hydrogen binding energy (HBE) and pH is observed for four supported platinum-group metal catalysts (Pt/C, Ir/C, Pd/C, and Rh/C) over a broad pH range (0 to 13), suggesting that the pH dependence of HBE is metal-independent. A universal correlation between exchange current density and HBE is also observed on the four metals, indicating that they may share the same elementary steps and rate-determining steps and that the HBE is the dominant descriptor for HOR/HER activities. The onset potential of CO stripping on the four metals decreases with pH, indicating a stronger OH adsorption, which provides evidence against the promoting effect of adsorbed OH on HOR/HER.

scholarly journals Platinum and Platinum Group Metal-Free Catalysts for Anion Exchange Membrane Fuel Cells

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 582 ◽  
Author(s):  
Van Men Truong ◽  
Julian Richard Tolchard ◽  
Jørgen Svendby ◽  
Maidhily Manikandan ◽  
Hamish A. Miller ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Anion Exchange ◽  
Peak Power ◽  
Hydrogen Oxidation ◽  
Anion Exchange Membrane ◽  
Platinum Group Metals ◽  
Flame Spray ◽  
Hydrogen Oxidation Reaction ◽  
Platinum Group ◽  
Exchange Membrane

The development of active hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) catalysts for use in anion exchange membrane fuel cells (AEMFCs), which are free from platinum group metals (PGMs), is expected to bring this technology one step closer to commercial applications. This paper reports our recent progress developing HOR Pt-free and PGM-free catalysts (Pd/CeO2 and NiCo/C, respectively), and ORR PGM-free Co3O4 for AEMFCs. The catalysts were prepared by different synthesis techniques and characterized by both physical-chemical and electrochemical methods. A hydrothermally synthesized Co3O4 + C composite ORR catalyst used in combination with Pt/C as HOR catalyst shows good H2/O2 AEMFC performance (peak power density of ~388 mW cm−2), while the same catalyst coupled with our flame spray pyrolysis synthesised Pd/CeO2 anode catalysts reaches peak power densities of ~309 mW cm−2. Changing the anode to nanostructured NiCo/C catalyst, the performance is significantly reduced. This study confirms previous conclusions, that is indeed possible to develop high performing AEMFCs free from Pt; however, the challenge to achieve completely PGM-free AEMFCs still remains.

Uniform Pd0.33Ir0.67 nanoparticles supported on nitrogen-doped carbon with remarkable activity toward the alkaline hydrogen oxidation reaction

2019 ◽  
Vol 7 (7) ◽  
pp. 3161-3169 ◽  
Author(s):  
Yuanyuan Cong ◽  
Ian T. McCrum ◽  
Xueqiang Gao ◽  
Yang Lv ◽  
Shu Miao ◽  
...  
Keyword(s):  
Oxidation Reaction ◽  
Hydrogen Oxidation ◽  
Hydrogen Binding ◽  
Hydrogen Oxidation Reaction ◽  
Nitrogen Doped ◽  
Electrocatalytic Performance ◽  
Nitrogen Doped Carbon

The excellent alkaline HOR electrocatalytic performance on Pd1−xIrx/N-C arises from the appropriate strength of hydrogen binding and the strongest oxophilic property.

scholarly journals Correlating hydrogen oxidation and evolution activity on platinum at different pH with measured hydrogen binding energy

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Wenchao Sheng ◽  
Zhongbin Zhuang ◽  
Minrui Gao ◽  
Jie Zheng ◽  
Jingguang G. Chen ◽  
...  
Keyword(s):  
Binding Energy ◽  
Hydrogen Oxidation ◽  
Hydrogen Binding

Study of IrxMny(CO)n(DMF)z as Electrocatalyst for Oxygen Reduction and Hydrogen Oxidation in the Presence of Fuel Cell Contaminants

2016 ◽  
Vol 19 (4) ◽  
pp. 185-192 ◽  
Author(s):  
M.L. Barrios-Reyna ◽  
J. Uribe-Godínez ◽  
J.M. Olivares-Ramírez ◽  
O. Jiménez-Sandoval
Keyword(s):  
Oxygen Reduction ◽  
Hydrogen Oxidation ◽  
Rotating Disk ◽  
Pem Fuel Cells ◽  
Platinum Group Metals ◽  
The Novel ◽  
Hydrogen Oxidation Reaction ◽  
Acid Media ◽  
X Ray ◽  
Wide Range

The oxygen reduction reaction (ORR) and the hydrogen oxidation reaction (HOR) have been studied on a wide range of elec-trocatalysts, including bimetallic materials which are based solely on platinum group metals and their alloys. This work reports the synthe-sis and characterization of a novel bimetallic electrocatalyst, IrxMny(CO)n(DMF)z, for the ORR and HOR in acid media. The material was synthesized by reacting Ir4(CO)12 and MnCl2·4H2O in DMF. It was characterized structurally by FT-IR and micro-Raman spectroscopy, X-ray diffraction, SEM and energy-dispersive X-ray spectroscopy; the electrochemical characterization was made by the rotating disk elec-trode technique, at room temperature. The electrocatalytic activity of the new material for the ORR and HOR does not show appreciable variations due to the presence of methanol or carbon monoxide, respectively, even at high concentrations of these contaminants (2 mol L-1 methanol and 0.5% CO). This tolerance is a very important property with respect to platinum-based catalysts, which are poisoned by low concentrations of such contaminants. The kinetic parameters of the novel catalyst, such as Tafel slope (b), exchange current density (jo) and charge transfer coefficient (α), are reported as well. The results show that the novel electrocatalyst is attractive for evaluation as cath-ode/anode in PEM fuel cells.

scholarly journals An Efficient Nickel Hydrogen Oxidation Catalyst for Hydroxide Exchange Membrane Fuel Cells

2021 ◽  
Author(s):  
Weiyan Ni ◽  
Teng Wang ◽  
Florent Heroguel ◽  
Anna Krammer ◽  
seunghwa lee ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hydrogen Oxidation ◽  
Platinum Group Metal ◽  
Carbon Support ◽  
Oxidation Catalyst ◽  
Electronic Interaction ◽  
Ni Nanoparticles ◽  
Hydrogen Binding ◽  
Hydrogen Oxidation Reaction ◽  
Exchange Membrane

The hydroxide exchange membrane fuel cell (HEMFC) is a promising energy conversion technology, but it is limited by the need of platinum-group-metal (PGM) electrocatalysts, especially for the hydrogen oxidation reaction (HOR). Here we report a Ni-based HOR catalyst that exhibits an electrochemical surface area-normalized exchange current density of 70 μA/cm2, the highest among PGM-free catalysts. The catalyst comprises of Ni nanoparticles embedded in a nitrogen-doped carbon support. According to X-ray and ultraviolet photoelectron spectroscopy as well as H2 chemisorption, the electronic interaction between the Ni nanoparticles and its support leads to an optimal hydrogen binding energy, which is the likely origin of its high activity. PGM-free HEMFCs employing this Ni HOR catalyst give a peak power density of 450 mW/cm2, up to 6 times higher than previous best-performing analogous. This work demonstrates the feasibility of efficient PGM-free HEMFCs.<br>

scholarly journals Hydrogen Oxidation on Ni-Based Electrocatalysts: The Effect of Metal Doping

2018 ◽  
Author(s):  
Elena S. Davydova ◽  
Jérémie Zaffran ◽  
Kapil Dhaka ◽  
Maytal Caspary Toroker ◽  
Dario R. Dekel
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Binding Energy ◽  
Density Functional ◽  
Hydrogen Oxidation ◽  
Ni Catalyst ◽  
Hydrogen Chemisorption ◽  
Hydrogen Binding ◽  
X Ray ◽  
Transmission Electron

Carbon supported nanoparticles of monometallic Ni catalyst and binary Ni-Transition Metal (Ni-TM/C) electrocatalytic composites were synthesized via chemical reduction method, where TM stands for the doping elements Fe, Co, and Cu. The chemical composition, structure and morphology of the Ni-TM/C materials were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDS). The electrochemical properties towards hydrogen oxidation reaction in alkaline medium were studied using the rotating disc electrode and cycling voltammetry methods. A significant role of the TM dopant in the promotion of the hydrogen electrooxidation kinetics of the binary Ni-TM/C materials were revealed. A record-high in exchange current density value of 0.060 mA cm2Ni was measured for Ni3Fe1/C, whereas the monometallic Ni/C counterpart has only shown 0.039 mA cm2Ni. In order to predict the feasibility of the electrocatalysts for hydrogen chemisorption, density functional theory was applied to calculate the hydrogen binding energy and hydroxide binding energy values for bare Ni and Ni3TM1.

scholarly journals An Efficient Nickel Hydrogen Oxidation Catalyst for Hydroxide Exchange Membrane Fuel Cells

2021 ◽  
Author(s):  
Weiyan Ni ◽  
Teng Wang ◽  
Florent Heroguel ◽  
Anna Krammer ◽  
seunghwa lee ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hydrogen Oxidation ◽  
Platinum Group Metal ◽  
Carbon Support ◽  
Oxidation Catalyst ◽  
Electronic Interaction ◽  
Ni Nanoparticles ◽  
Hydrogen Binding ◽  
Hydrogen Oxidation Reaction ◽  
Exchange Membrane

The hydroxide exchange membrane fuel cell (HEMFC) is a promising energy conversion technology, but it is limited by the need of platinum-group-metal (PGM) electrocatalysts, especially for the hydrogen oxidation reaction (HOR). Here we report a Ni-based HOR catalyst that exhibits an electrochemical surface area-normalized exchange current density of 70 μA/cm2, the highest among PGM-free catalysts. The catalyst comprises of Ni nanoparticles embedded in a nitrogen-doped carbon support. According to X-ray and ultraviolet photoelectron spectroscopy as well as H2 chemisorption, the electronic interaction between the Ni nanoparticles and its support leads to an optimal hydrogen binding energy, which is the likely origin of its high activity. PGM-free HEMFCs employing this Ni HOR catalyst give a peak power density of 450 mW/cm2, up to 6 times higher than previous best-performing analogous. This work demonstrates the feasibility of efficient PGM-free HEMFCs.<br>

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