Addressed herein, we report the development of highly efficient and monodisperse Pt(0) nanoclusters for the dehydrocoupling of dimethylamine–borane (DMAB) which is considered to be one of the new hydrogen storage materials. The prepared Pt(0) nanoclusters were in situ generated for the first time from the reduction of PtCl₄ and use of dipentylamine (DPA) and tripentylamine (TPA) ligands on activated carbon for the dehydrocoupling of dimethylamine–borane at room temperature and characterized by ICP-OES, XRD, TEM, HR-TEM, AFM, EDX, and XPS techniques. All the results show that highly crystalline and stable colloidal Pt(0)/DPA@AC and Pt(0)/TPA@AC nanoparticles have been formed and Pt(0)/DPA@AC and Pt(0)/TPA@AC were found to be two of the most active and long-lived catalysts with superior reusability performance in the dehydrocoupling of DMAB at room temperature.