Herein we report the discovery of a superior dimethylamine-borane dehydrogenation catalyst, more active than the prior best heterogeneous catalyst (Celik B.; Yildiz Y.; Sert H.; Erken E.; Koskun Y.; and Sen F.; RSC Advances 2016, 6, 24097-24102) reported to date for the dehydrogenation of dimethylamine-borane. The new catalyst system consists of well dispersed ruthenium-cobalt nanomaterials decorated on functionalized multiwalled carbon nanotube (3.72 +/- 0.37 nm) prepared by the use of the ultrasonic double reduction method. The morphology and structure composition of catalytically effective, recyclable and reproducible catalysts were fully characterized by using different analytical techniques such as UV-Vis, XPS, TEM, XRD and HR-TEM-EELS analyses. This catalyst showed best ever catalytic activity with a very high turnover frequency (775.28 h(-1)) and low E. value of 13.72 +/- 2 kJ/mol for DMAB dehydrocoupling in the ambient conditions yielding 100% of the cyclic product (Me2NBH2)(2) at room temperature. Besides, RuCo@f-MWCNT catalyst exhibits great reusability, high catalytic performance and excellent durability for dimethylamine-borane dehydrogenation reaction. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.