Use of catalysts located in the 12 principles of Green Chemistry is an important area of research. Application and investigation of catalysts that are non-perishable after use, nontoxic, easily separated and reusable after reaction can be considered one of the vital areas for the chemical industry. In addition to supercritical fluids, ionic liquids and fluorinated solvents produced and used for this purpose, "The best solvent is no solvent" approach has been the focus of our attention in this work. Herein, generation of hydrogen from solvent free catalytic dehydrogenation of dimethylamine-borane that has low melting point was obtained using the simple mechanical mixing technique in accordance with the green synthesis principles. In addition, in situ synthesis of active ruthenium nanoclusters prepared using precursor Ru(acac)(3) salt in presence of various supporters such as Poly vinyl pyrrolidone, poly (styrene-co-maleic anhydride) and alumina was carried out and the activities of these nanoclusters were compared by classical methods investigating with many parameters. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.