Rare earth metal oxides as BH4−-tolerance cathode electrocatalysts for direct borohydride fuel cells

Rare earth metal oxides (REMO) as cathode electrocatalysts in direct borohydride fuel cell (DBFC) were investigated. The REMO electrocatalysts tested showed favorable activity to the oxygen electro-reduction reaction and strong tolerance to the attack of BH4− in alkaline electrolytes. The simple membraneless DBFCs using REMO as cathode electrocatalyst and using hydrogen storage alloy as anodic electrocatalyst exhibited an open circuit of about 1 V and peak power of above 60 mW/cm2. The DBFC using Sm2O3 as cathode electrocatalyst showed a relatively better performance. The maximal power density of 76.2 mW/cm2 was obtained at the cell voltage of 0.52 V.