Carbon materials should have specific centers for hydrogen adsorption/absorption. The Universal Force Field and Density Functional Theory have been used to find the role of heteroatom substitution in carbon nanotubes as an activator. The effect of various heteroatoms like nitrogen, phosphorus, sulphur and boron for hydrogen activation and their geometrical positions has been identified for easy hydrogenation. This will be one of the possible centers where hydrogen adsorption/absorption is initiated. © 2006 Elsevier Ltd. All rights reserved.