Molecular hydrogen is dissociatively adsorbed at elevated temperatures on Ga3+ surface sites of supported gallium catalysts. Both the amount of hydrogen absorbed by the catalysts and Ga-H vibration frequencies of surface gallium hydrides formed upon dissociative hydrogen adsorption depend on the nature of the support. The surface sites, active in the dissociative adsorption of hydrogen, most probably are Ga3+ cations bonded to the support surface. (C) 2012 Elsevier B.V. All rights reserved.