JCE Online Journal of Chemical Education
 | Subscriptions  | Software Orders  | Support  | Contributors  | Advertisers  | 

JCE Print
   Current Issue
 Previous Issues
 Supplements
 Search JCE Index

JCE Digital Library
   DigiDemos
 QBank
 SymMath
 WebWare

JCE Software
   Latest Releases
 Software & Video
 Downloads
 Support

Only@JCE Online
   JCE Online Store
 JCE HS CLIC
 JCE Discussion Forums
   Biographical Snapshots
 ChemEd Resource Shelf
 Featured Molecules
 Hal's Picks
 Project Chemlab
 Reviewed WWW Sites
 "Web-Ed" Articles

About JCE
   Features
 Publications
 Operations
 Outreach
 Contact Us


  Home > JCE Print > Journal of Chemical Education > Issues > 2000  > September  >
In the Laboratory
Determination of the Real Surface Area of Pt Electrodes by Hydrogen Adsorption Using Cyclic Voltammetry
Jose M. Doña Rodríguez, José Alberto Herrera Melián, and Jesús Pérez Peña
Departamento de Química, Universidad de Las Palmas de Gran Canaria, Islas Canarias, Spain
Cover
September 2000
Vol. 77 No. 9
p. 1195
Abstract
It is well known that the electrical current of an electrochemical process is proportional to the real surface area of the electrode. The presence of surface rugosities due to steps, holes, kinks, and terraces can result in an electrode real surface area that is larger than the geometric one. The electrode real surface area can be evaluated by determining the amount of gas that adsorbs onto the electrode surface. This calculation is possible because every adsorbed gas molecule is attached to one metal atom on the electrode surface, forming a gas monolayer. From crystallographic data the surface atom density can be obtained in consideration of a theoretically flat metal surface. These data allow us to determine the real electrode surface area. In this paper we propose a simple experiment to determine the real surface area of a Pt electrode by voltammetry. The hydrogen adsorption on this metal is achieved by applying sufficiently negative potentials to a Pt electrode in contact with an aqueous solution. Each adsorbed hydrogen atom requires the transfer of one electron. Hydrogen gas evolution starts only when the monolayer is completed. Then the cathodic current rapidly rises. The hydrogen monolayer formation charge transference can be calculated by integrating the voltammetric curves. The integration limits are the potentials at which the hydrogen adsorption and evolution start.
More Information
*  Citation
 Doña Rodríguez, Jose M.; Herrera Melián, José Alberto; Pérez Peña, Jesús. J. Chem. Educ. 2000 77 1195.
*  Keywords
 Catalysis; Electrochemistry; Materials Science; Surface Science
*  History
 Created:
Last Updated:		 August 29, 2000
June 22, 2005
<< Previous Article Table of Contents Next Article >>
  Home > JCE Print > Journal of Chemical Education > Issues > 2000 > September > Page 1195


Subscriptions
 Subscription Info
 Order Forms

JCE HS CLIC

Our Secondary School editors work hard to distill all the JCE materials to produce a fraction of particular interest to high school teachers. We call it CLIC.
 JCE HS CLIC

Contributions Welcome
JCE welcomes your submission
 Contributors' Corner

Advertisers
In recent years we have worked hard to better match our advertisers with our readers. When shopping for chemistry education materials, visit our advertisers' WWW sites first.
 Recent Advertisers

Be An Ambassador
Take JCE along on your outreach missions. Copies of the Journal, guest access to JCE Online, our publications catalog, and more are available for your participants.
 Outreach with JCE

Comments to
jceonline@chem.wisc.edu		 Copyright © Division of Chemical Education, Inc., American Chemical Society.
All rights reserved.