scholarly journals The oxygen reduction reaction (ORR) on reduced metals: evidence for a unique relationship between the coverage of adsorbed oxygen species and adsorption energy

2016 ◽  
Vol 18 (15) ◽  
pp. 10218-10223 ◽  
Author(s):  
S. C. Perry ◽  
G. Denuault
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Adsorption Energy ◽  
Reduction Reaction ◽  
Adsorbed Oxygen ◽  
Oxygen Species ◽  
Adsorbed Oxygen Species ◽  
Unique Relationship

The ORR current follows a volcano-like dependence on the coverage of oxygen species that adsorb upon exposure to dissolved oxygen and on their adsorption energy.

scholarly journals Transient study of the oxygen reduction reaction on reduced Pt and Pt alloys microelectrodes: evidence for the reduction of pre-adsorbed oxygen species linked to dissolved oxygen

2015 ◽  
Vol 17 (44) ◽  
pp. 30005-30012 ◽  
Author(s):  
S. C. Perry ◽  
G. Denuault
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Reduction Reaction ◽  
Adsorbed Oxygen ◽  
Oxygen Species ◽  
Adsorbed Oxygen Species ◽  
Pt Alloys ◽  
Transient Study ◽  
Microdisc Electrodes

Below 100 ms the reduction of oxygen on oxide-free Pt microdisc electrodes reveals the existence of oxygen species which adsorb on the electrode before the reduction is electrochemically driven.

Catalytic Activity of Silver Metal Supported on Doped Graphene in Alkaline Medium for Oxygen Reduction Reaction

2019 ◽  
Vol 1155 ◽  
pp. 55-69
Author(s):  
Nabila A. Karim ◽  
Nor Shahirah Shamsul ◽  
Siti Kartom Kamarudin
Keyword(s):  
Fuel Cell ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Adsorption Energy ◽  
Reduction Reaction ◽  
Pt Catalyst ◽  
Nitrogen And Phosphorus ◽  
Doped Graphene ◽  
Phosphorus Doped ◽  
Silver Metal

The platinum (Pt) degradation, poisoning and carbon corrosion in acidic fuel cell has led to explore the research in alkaline fuel cell. However, the high cost of Pt has brought a lot of studies to find replacement for Pt catalyst. Due to that, silver metal is selected as non-Pt catalyst and supported by the nitrogen and phosphorus-doped on graphene for oxygen reduction reaction in alkaline medium. The adsorption energy and mechanism of the oxygen reduction reaction is studied by using density functional theory (DFT) calculation. The support catalyst of graphene is doped with three atom nitrogen and phosphorus namely as N3 and P3, respectively. The Ag supported on N3 and P3 are tested on O2, OOH, O and OH species. There are two types adsorption of O2 on N3 and P3 which is side and end-on adsorption configuration. The N3-Ag has similar adsorption energy for both configurations, but P3-Ag has low adsorption energy by end-on adsorption configuration. The effect of doped atoms on graphene also have been tested on O2, OOH, O and OH species. The result shows that increasing nitrogen doping atom has decreased the adsorption energy of O2 and vice versa on phosphorus atoms. A single phosphorus doping atom on graphene has shown the lowest adsorption energy, but the end-on configuration of P3-Ag has shown most stable adsorption. The schematic free energy profile shows that both N3-Ag and P3-Ag have high possibilities to be followed in oxygen reduction reaction mechanism but P3-Ag has advantage due to stable adsorption as non-Pt catalyst. The Ag metal supported on nitrogen and phosphorus-doped graphene show promising result to be a catalyst in alkaline fuel cell.

scholarly journals Oxygen Reduction Reaction Catalyzed by Pt3M (M = 3d Transition Metals) Supported on O-doped Graphene

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 156
Author(s):  
Chaonan Cui ◽  
Mengnan Sun ◽  
Xinli Zhu ◽  
Jinyu Han ◽  
Hua Wang ◽  
...  
Keyword(s):  
Transition Metals ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Adsorption Energy ◽  
Density Functional ◽  
Energy Difference ◽  
Oxygen Adsorption ◽  
Reduction Reaction ◽  
Computational Method ◽  
Doped Graphene

Pt3M (M = 3d transition metals) supported on oxygen-doped graphene as an electrocatalyst for oxygen reduction was investigated using the periodic density functional theory-based computational method. The results show that oxygen prefers to adsorb on supported Pt3M in a bridging di-oxygen configuration. Upon reduction, the O–O bond breaks spontaneously and the oxygen adatom next to the metal–graphene interface is hydrogenated, resulting in co-adsorbed O* and OH* species. Water formation was found to be the potential-limiting step on all catalysts. The activity for the oxygen reduction reaction was evaluated against the difference of the oxygen adsorption energy on the Pt site and the M site of Pt3M and the results indicate that the oxygen adsorption energy difference offers an improved prediction of the oxygen reduction activity on these catalysts. Based on the analysis, Pt3Ni supported on oxygen-doped graphene exhibits an enhanced catalytic performance for oxygen reduction over Pt4.

scholarly journals Polyhedral Effects on the Mass Activity of Platinum Nanoclusters

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1010
Author(s):  
Forrest H. Kaatz ◽  
Adhemar Bultheel
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Adsorption Energy ◽  
Density Functional ◽  
Reduction Reaction ◽  
Lognormal Distributions ◽  
Langmuir Hinshelwood Mechanism ◽  
Mass Activity ◽  
Kinetics Of ◽  
Platinum Nanoclusters

We use a coordination-based kinetics model to look at the kinetics of the turnover frequency (TOF) for the oxygen reduction reaction (ORR) for platinum nanoclusters. Clusters of octahedral, cuboctahedral, cubic, and icosahedral shape and size demonstrate the validity of the coordination-based approach. The Gibbs adsorption energy is computed using an empirical energy model based on density functional theory (DFT), statistical mechanics, and thermodynamics. We calculate the coordination and size dependence of the Gibbs adsorption energy and apply it to the analysis of the TOF. The platinum ORR follows a Langmuir–Hinshelwood mechanism, and we model the kinetics using a thermodynamic approach. Our modeling indicates that the coordination, shape, and the Gibbs energy of adsorption all are important factors in replicating an experimental TOF. We investigate the effects of size and shape of some platinum polyhedra on the oxygen reduction reaction (ORR) and the effect on the mass activity. The data are modeled quantitatively using lognormal distributions. We provide guidance on how to account for the effects of different distributions due to shape when determining the TOF.

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