Generally, the electrocatalysts are immobilized on conductive electrodes or in-situ grown on current-collecting substrates, which causes some disadvantages. For the first time, the obtained porous molybdenum carbide microspheres with diameters of 200-400 mu m are employed as binder-free electrocatalysts in the novel model of suspended hydrogen evolution reaction (SHER), which possess the perfect catalytic stability and high practicability. Herein, porous molybdenum carbide microspheres synthesized by ion exchange reaction and subsequent calcining process are employed as electrocatalysts for HER, which possess a low onset potential of -79 mV vs. RHE and a low overpotential of 174 mV achieving a current density of 10 mA/cm(2) in 0.5 M H2SO4. This work may provide a new methodology for rational design and fabrication of reaction pattern for the electrolysis of water. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.