OXIDATION OF PYROLYTIC GRAPHITE BETWEEN 1250 F AND 1850 F

Abstract

The oxidation of pyrolytic graphite was studied as a function of time and temperature. Pyrolytic graphite does not oxidize as rapidly as commercial graphite at temperatures below 1450 F but approaches that of commercial graphite at 1550 F. Oxidation of pyrolytic graphite proceeds preferentially in the c-direction contrary to expectation. The break in the Arrhenium plot for pyrolytic graphite occurring at 1550 F may beATTRIBUTED TO THE CHANGE IN CONTROL MECHANISM FROM CHEMICAL REACTIVITY TO DIFFUSION CONTROL. An activation energy of 37,180 calories per mol was calculated for a commercial graphite. The activation energy calculated for pyrolytic graphite was 23,350 calories per mol. The lower activation energy for pyrolytic graphite is associated with a lower reaction rate. This anomalous behavior is attributed to its lower porosity since a less porous material exposes a smaller surface area for molecular collisions. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 01, 1961
Accession Number
AD0260253

Entities

People

  • Milton Levy

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Chemical Reaction Properties
  • Chemical Reactions
  • Collisions
  • Diffusion
  • Energy
  • Graphitic Materials
  • Heat Of Activation
  • Materials
  • Oxidation
  • Porosity
  • Porous Materials
  • Reactivities
  • Reinforcing Materials

Readers

  • Electrochemical Engineering/ Fuel Cell Technologies
  • Materials Science and Engineering.