Hydrogen sorption properties of Pd-doped carbon molecular sieves

Decoration with transition metal catalysts has been reported to enhance H₂ storage capacity of carbon materials at ambient temperature. Furthermore, it has been proposed that surface oxygen groups may improve the process. In this study, a carbon molecular sieve was subjected to controlled oxidation and consequent doping with Pd nanoparticles. The H₂ sorption performance of the pristine and oxidized, undoped and doped materials was examined at 298 K up to 20 bar. It was found that the non-oxidized carbon-Pd composite did not show any spillover based sorption increase. On the other hand the oxidized samples reveal a slight enhancement that could be attributed to a weak chemisorption process initiated by the so-called ‘‘spillover’’ effect. Overall, the contribution of spillover to the total hydrogen storage capacity of this system (under the conditions studied) was not found to be of great significance.