PdCu nanoparticles modified free-standing reduced graphene oxide framework as a highly efficient catalyst for direct borohydride-hydrogen peroxide fuel cell

A novel electrode of PdCu nanoparticles modified free-standing reduced graphene oxide (rGO) framework (PdCu@rGOF) is fabricated via electrodeposition and chemical reduction and employed to the direct sodium borohydride-hydrogen peroxide fuel cell (DBHPFC). The resultant catalyst reveals excellent catalytic perfor-mance towards hydrogen peroxide (H2O2) electroreduction reaction (HPRR) and sodium borohydride (NaBH4) electrooxidation reaction (BOR) along with low activation energy (Ea). Numerically, the PdCu@rGOF electrode delivers an HPRR current density of 455.2 mA cm -2 at 0 V (2 mol L-1 H2SO4+1.3 mol L-1 H2O2). Additionally, the current density of BOR reaches up to 1065.3 mA cm -2 at 0 V for 2 mol L-1 NaOH and 0.3 mol L-1 NaBH4. Meanwhile, the mechanism studies show that HPRR and BOR catalyzed by PdCu@rGOF mainly relates 2 -elec-tron-transfer process and quasi-8-electron-transfer process, respectively. Subsequently, PdCu@rGOF is assem-bled into a fuel cell, yielding the optimal power density of 188.9 mW cm -2. The open circuit potential (OCP) of DBHPFC is about 1.70 V at 293.15 K. The superior electrochemical performance of the optimized electrode can be attributed to the distinctive architecture and the strong adsorption and bond-breaking ability of Pd nano -particles. This work indicates that the as-prepared PdCu@rGOF can be a promising catalyst for DBHPFC.