A NiMn Binary Nanocatalyst for Borohydride Electrooxidation.

Direct borohydride fuel cells (DBFCs) demonstrate high theoretical energy density and work voltage, yet their practical implementation relies critically on the performance of anode catalysts. These challenges are effectively addressed by the NiMn binary nanocatalyst fabricated via an electrodeposition. Mn introduction primarily enhances the apparent activity by refining particles and increasing active site density, while moderately improving the intrinsic activity through electronic structure modulation and effectively suppressing HER and Ni oxidation to improve selectivity and stability. Moreover, the DBFC using this nanocatalyst anode can deliver a maximum power density of 391 mW cm-2 and an open-circuit voltage of 1.89 V at 298 K, while it can run stably for 45 h under 100 mA cm-2.