Electrosynthesis of dendritic palladium supported on Ti/TiO2NTs/Ni/CeO2 as high-performing and stable anode electrocatalyst for methanol electrooxidation

Abstract

Liquid-fueled direct methanol fuel cell (DMFC) is highly promising for low-carbon transportation, but is hindered by high cost and short lifespan of conventional Pt-based electrocatalysts. Herein, we propose a new Pt-free catalyst strategy to exploit high-performing and stable electrocatalyst of DMFC, achieving enhanced electrocatalytic activity and high stability for methanol oxidation reaction (MOR) in alkaline media. A new Pt-free anode catalysts consisting of titanium/reduced-titanium dioxide nanotubes/nickel/cerium dioxide (Ti/r-TiO2NTs/Ni/CeO2) nanosupport and uniformly-dispersed Pd dendrites is successfully prepared by a facile three-step electrodeposition route without applying any template or surfactant. Noticeably, the as-prepared Ti/r-TiO2NTs/Ni/CeO2–Pd as an anode electrode exhibits superior activity than commercial Pd/C and other electrodes. The obtained large mass activity for Ti/r-TiO2NTs/Ni/CeO2–Pd electrode is 1752 mA mgPd−1 for MOR. After successive CV tests of 1000 cycles, Ti/r-TiO2NTs/Ni/CeO2–Pd electrode still retained 88.9% of its initial current. The superior performance of Ti/r-TiO2NTs/Ni/CeO2–Pd attributes to the large surface area and excellent conductivity, as well as the synergistic effects among nanosupport and Pd dendrites. Therefore, this study will open a new door for high-performance fuel cell applications.