skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Evidence for decoupled electron and proton transfer in the electrochemical oxidation of ammonia on Pt(100)

Journal Article · · Journal of Physical Chemistry Letters
 [1];  [2];  [3];  [4];  [5]
  1. Univ. of Illinois-Champaign, Urbana, IL (United States); Argonne National Lab. (ANL), Lemont, IL (United States); Leiden Univ., Leiden (The Netherlands)
  2. Leiden Univ., Leiden (The Netherlands); Shandong Jianzhu Univ., Jinan (People's Republic of China)
  3. Univ. of Illinois-Champaign, Urbana, IL (United States)
  4. Argonne National Lab. (ANL), Lemont, IL (United States)
  5. Leiden Univ., Leiden (The Netherlands)
+ Show Author Affiliations

The two traditional mechanisms of the electrochemical ammonia oxidation consider only concerted proton-electron transfer elementary steps and thus they predict that the rate–potential relationship is independent of the pH on the pH-corrected RHE potential scale. In this letter we show that this is not the case: the increase of the solution pH shifts the onset of the NH3-to-N2 oxidation on Pt(100) to lower potentials and also leads to higher surface concentration of formed NOad before the latter is oxidized to nitrite. Therefore, we present a new mechanism for the ammonia oxidation which incorporates a deprotonation step occurring prior to the electron transfer. The deprotonation step yields a negatively charged surface-adsorbed species which is discharged in a subsequent electron transfer step before the N–N bond formation. The negatively charged species is thus a precursor for the formation of N2 and NO. The new mechanism should be a future guide for computational studies aiming at the identification of intermediates and corresponding activation barriers for the elementary steps. As a result, ammonia oxidation is a new example of a bond-forming reaction on (100) terraces which involves decoupled proton-electron transfer.

Research Organization:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC02-06CH11357
OSTI ID:
1248379
Journal Information:
Journal of Physical Chemistry Letters, Vol. 7, Issue 3; ISSN 1948-7185
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 47 works
Citation information provided by
Web of Science

References (34)

Nitrogen Cycle Electrocatalysis journal June 2009
On the use of ammonia electrolysis for hydrogen production journal March 2005
Electro-oxidation of ammonia in waste water journal July 1978
Electrochemical oxidation of ammonia in alkaline solutions: its application to an amperometric sensor journal January 1998
DEMS-cyclic voltammetry investigation of the electrochemistry of nitrogen compounds in 0.5 M potassium hydroxide journal January 1994
A DEMS and cyclic voltammetry study of NH3 oxidation on platinized platinum journal May 1998
The role of adsorbates in the electrochemical oxidation of ammonia on noble and transition metal electrodes journal June 2001
The Anodic Oxidation of Ammonia at Platinum Black Electrodes in Aqueous koh Electrolyte journal July 1963
Untersuchungen Zur anodischen Oxidation von Ammoniak an Platin-Elektroden journal May 1970
Selective electrocatalysis of ammonia oxidation on Pt(100) sites in alkaline medium journal January 2003
Ammonia Selective Oxidation on Pt(100) Sites in an Alkaline Medium journal July 2005
DEMS study of ammonia oxidation on platinum basal planes journal March 2006
Electrocatalytic oxidation of ammonia on Pt(111) and Pt(100) surfaces journal January 2006
Bond-Making and Breaking between Carbon, Nitrogen, and Oxygen in Electrocatalysis journal October 2014
Unique Activity of Platinum Adislands in the CO Electrooxidation Reaction journal November 2008
Selective Catalytic Reduction at Quasi-Perfect Pt(100) Domains: A Universal Low-Temperature Pathway from Nitrite to N 2 journal July 2011
Structure Sensitivity of the Electrochemical Reduction of Carbon Monoxide on Copper Single Crystals journal April 2013
Why (1 0 0) Terraces Break and Make Bonds: Oxidation of Dimethyl Ether on Platinum Single-Crystal Electrodes journal September 2013
Structural effects in electrocatalysis journal May 1984
The influence of pH on the reduction of CO and CO 2 to hydrocarbons on copper electrodes journal March 2014
Theory of the transition from sequential to concerted electrochemical proton–electron transfer journal January 2013
Theory of multiple proton–electron transfer reactions and its implications for electrocatalysis journal January 2013
Volcano Activity Relationships for Proton-Coupled Electron Transfer Reactions in Electrocatalysis journal September 2015
On the behavior of the Pt(100) and vicinal surfaces in alkaline media journal December 2011
Electrochemistry of Pt (100) in alkaline media: A voltammetric study journal October 2010
Mechanistic Similarity in Catalytic N 2 Production from NH 3 and NO 2 – at Pt(100) Thin Films: Toward a Universal Catalytic Pathway for Simple N-Containing Species, and Its Application to in Situ Removal of NH 3 Poisons journal April 2015
Hydrogen adsorption on single-crystal platinum electrodes in alkaline solutions journal July 1992
Ammonia Dehydrogenation over Platinum-Group Metal Surfaces. Structure, Stability, and Reactivity of Adsorbed NH x Species journal January 2007
Near-surface ion distribution and buffer effects during electrochemical reactions journal January 2011
Nitric oxide adsorption at Pt(100) electrode surfaces journal November 1998
Combined First-Principles Molecular Dynamics/Density Functional Theory Study of Ammonia Electrooxidation on Pt(100) Electrode journal November 2013
Electrocatalytic Oxidation of Ammonia on Transition-Metal Surfaces: A First-Principles Study journal February 2015
Theoretical study of ammonia oxidation on platinum clusters – Adsorption of ammonia and water fragments journal June 2012
Theoretical study of ammonia oxidation on platinum clusters – Adsorption of intermediate nitrogen dimer molecules journal July 2013

Cited By (3)

A Review of Electrocatalytic Reduction of Dinitrogen to Ammonia under Ambient Conditions journal May 2018
The Direct Ammonia Fuel Cell and a Common Pattern of Electrocatalytic Processes journal January 2018
Proton-coupled electron transfer in the electrocatalysis of CO 2 reduction: prediction of sequential vs. concerted pathways using DFT journal January 2017

Similar Records

Metal-organic framework-derived nitrogen-doped highly disordered carbon for electrochemical ammonia synthesis using N2 and H2O in alkaline electrolytes
Journal Article · Fri Mar 23 00:00:00 EDT 2018 · Nano Energy · OSTI ID:1248379
+7 more
The complex extracellular domain regulates the deprotonation and reprotonation of the retinal Schiff base during the bacteriorhodopsin photocycle
Journal Article · Tue Oct 03 00:00:00 EDT 1995 · Biochemistry (Eaton) · OSTI ID:1248379
Understanding the Role of Inter- and Intramolecular Promoters in Electro- and Photochemical CO 2 Reduction Using Mn, Re, and Ru Catalysts
Journal Article · Tue Feb 08 00:00:00 EST 2022 · Accounts of Chemical Research · OSTI ID:1248379
+1 more

Related Subjects

ammonia oxidation
bond-forming reactions
nitrogen cycle
pH effects
sequential proton-electron transfer