The oxidation behavior of carbon materials has been investigated at temperatures less than 773 K using isothermal thermogravimetric analyses under dry and wet air. Bulk samples obtained by the pyrolysis of phenolic resin have been characterized using X-ray diffraction and elementary analysis. X-ray photoelectron spectroscopy and Raman spectroscopy have been performed to analyze the surface and subsurface. The carbon structure has a poor organization state and a gradient in the oxygen concentration and structure between the surface and the bulk is revealed. The material is more reactive under wet air than dry air in terms of oxidation rates as determined between 623 and 773 K. The apparent activation energies are respectively 122 +/- 6 kJ/mol in dry air and 102 +/- 6 kJ/mol in wet air. (C) 2016 Elsevier B.V. All rights reserved.