Herein, a rapid and straightforward coreduction aqueous approach was developed for preparation of support-free trimetallic Pt53Ru39Ni8 nanosponges with clean surface. Plenty of hydrogen bubbles were in situ formed via the oxidation and hydrolysis of the reductant (sodium borohydride), which served as the dynamic template in the fabrication of the porous sponge-like structures. The shape, size, crystal structure, and composition of the products were characterized by a set of characterization techniques. The obtained Pt53Ru39Ni8 nanosponges displayed dramatically highly electrocatalytic performances for hydrogen evolution reaction (HER) and hydrazine oxidation reaction (HOR) outperformed home-made PtNi nanoparticles (PtNi NPs), RuNi NPs and commercial PtRu black (50 wt.%). The present route provides new insights for facile synthesis of other bi-, tri- and even multi-metallic nanocatalysts for potential applications in catalysis, energy conversion and storage. (C) 2017 Elsevier Inc. All rights reserved.