Hydrogen fuel cells work by instigating stored hydrogen to react with oxygen in air, producing electricity and water. however, generation of pure hydrogen fuel can be a challenging problem. the large-scale production of hydrogen gas is mostly achieved by steam-methane reforming. the major drawback of steam reforming is that – (i) it takes place at high temperature and thus requires external heat energy to maintain elevated temperature and (ii) process results in emission of greenhouse gases as by-product of the reaction. furthermore, hydrogen storage and transportation is expensive and requires exclusive tanks to store gas at enormously high pressure. in order to address this issue, we report chemically powered micromotors composed of a collection of iron nanoparticles (fenps), namely ferrobots, for rapid on-site generation of pure hydrogen gas using formic acid as fuel. instead of storing hydrogen gas in bulky pressurized tanks, motile ferrobots could be easily deployed in to aqueous formic acid solutions for on-demand release of pure hydrogen gas, devoid any of greenhouse gases, at room temperature. to demonstrate the proof-of-concept, reactive ferrobots were employed to power a portable toy fan equipped with pem fuel cell. the pure hydrogen gas required for pem fuel cell was generated through reaction of formic acid solution with self-propelling ferrobots, whereas, oxygen gas was produced by catalytic decomposition of peroxide fuel using same ferrobots. the as-generated hydrogen and oxygen gases were directly feed from reaction chambers to the fuel cell electrodes to generate electricity and thus power electronic toy fan. the advantage of this type of micromotor-mediated system is that liquid fuels are used for on-site hydrogen release, and thus gas storage will not be prerequisite in near future.