Noble metal nanoparticles including rhodium, ruthenium and palladium have been extensively used in catalysis field. Since their limited abundance and high cost, many methods have been developed to obtain highly active and recyclable catalysts. In this work, Rh3+, Ru3+, Pd2+ ions were impregnated on activated carbon derived from pumpkin stalk in distilled water and then reduced with sodium borohydride to form Rh-0, Ru-0, Pd-0 nanoparticles on the surface of carbon. The analyses show that these nanoparticles were successfully dispersed on the activated carbon. Rh-0, Ru-0, Pd-0 nanoparticles on activated carbon provide a turnover frequency value of 188 min(-1), 235 min(-1) and 40 min(-1), respectively, at 25.0 +/- 0.1 degrees C. They preserve their activity even after multiple use in H-2 generation from the hydrolysis of ammonia borane. (C) 2019 Elsevier Inc. All rights reserved.