Temperature-Programmed Desorption

Catalytic mechanisms and desorption from solids are studied using temperature-programmed desorption. In such a measurement, a molecule is adsorbed on a solid surface, the temperature is ramped linearly with time, and the rate of desorption is measured, usually with a mass spectrometer. This is essentially a small batch reactor whose temperature increases linearly with time. This Demonstration shows temperature-programmed desorption curves for three heating rates (1, 3, and 10 K/s). Changing heating rate is often used to determine heats of desorption. You can change the order of reaction, activation energy, and coverage. The rate of desorption is plotted either as a function of time or as a function of temperature.


  • [Snapshot]
  • [Snapshot]
  • [Snapshot]


As the heating rate increases, the temperature at which the desorption rate is a maximum (peak temperature) increases, and the maximum rate of desorption increases. When plotted on a time scale, as the heating rate increases, the maximum rate of desorption occurs at shorter times. As the activation energy for desorption increases, the peak temperature increases. This is one of the most widely-used techniques for characterizing catalysts and porous materials and for studying catalytic mechanisms.
Mole balance:
= concentration of A
= saturation coverage
= activation energy
= pre-exponential factor
= ideal gas constant
= temperature
= order of reaction
= time
Temperature-time relation:
= heating rate


(University of Colorado Boulder, Department of Chemical and Biological Engineering)
"Temperature-Programmed Desorption"
 Wolfram Demonstrations Project
 Published: June 17, 2013
    • Share:

Embed Interactive Demonstration New!

Just copy and paste this snippet of JavaScript code into your website or blog to put the live Demonstration on your site. More details »

Files require Wolfram CDF Player or Mathematica.

Mathematica »
The #1 tool for creating Demonstrations
and anything technical.
Wolfram|Alpha »
Explore anything with the first
computational knowledge engine.
MathWorld »
The web's most extensive
mathematics resource.
Course Assistant Apps »
An app for every course—
right in the palm of your hand.
Wolfram Blog »
Read our views on math,
science, and technology.
Computable Document Format »
The format that makes Demonstrations
(and any information) easy to share and
interact with.
STEM Initiative »
Programs & resources for
educators, schools & students.
Computerbasedmath.org »
Join the initiative for modernizing
math education.
Step-by-Step Solutions »
Walk through homework problems one step at a time, with hints to help along the way.
Wolfram Problem Generator »
Unlimited random practice problems and answers with built-in step-by-step solutions. Practice online or make a printable study sheet.
Wolfram Language »
Knowledge-based programming for everyone.
Powered by Wolfram Mathematica © 2017 Wolfram Demonstrations Project & Contributors  |  Terms of Use  |  Privacy Policy  |  RSS Give us your feedback
Note: To run this Demonstration you need Mathematica 7+ or the free Mathematica Player 7EX
Download or upgrade to Mathematica Player 7EX
I already have Mathematica Player or Mathematica 7+