Ru2P nanofibers for high-performance anion exchange membrane water electrolyzer

• Ru 2 P NFs are fabricated via phosphidation of electrospun RuO 2 NFs. • Ru 2 P NF coated carbon paper is employed as the cathode for AEMWE single cell. • The 3D porous cathode provides abundant active sites and a mass transport channel. • AEMWE shows remarkable performance, especially in high current density regions. The development of advanced electrodes with highly active electrocatalysts and appropriate structures is essential for sustainable hydrogen production via water electrolysis. Moreover, there is significant demand for an affordable electrocatalyst that exhibits comparable activity to that of Pt. Herein, we report Ru 2 P nanofibers (NFs) as an efficient electrode material for a high-performance anion exchange membrane water electrolyzer (AEMWE). The electrospinning method enables the formation of a porous catalyst layer that comprises tangled NFs, which exhibit a three-dimensional structure with abundant empty space. In a half cell test, the Ru 2 P NFs exhibit a high catalytic activity for the hydrogen evolution reaction, which is comparable to the activity of a commercial Pt/C. In a single cell test, an AEMWE with Ru 2 P NFs demonstrates a higher performance than that with a commercial Pt/C, especially in the high current density region; this is attributed to the structural advantage of the porous catalyst layer, which enhances the mass transfer of the reactant, as well as the product.