Pt loaded on 3D micro-flower-shaped NiFe layered double hydroxides as a highly active and durable methanol oxidation electrocatalyst

The search for CO-resistant methanol oxidation reaction (MOR) catalysts for direct methanol fuel cells (DMFC) is an important yet difficult task. The synergy materials Pt and M (M = Co, Fe, Ni, and Ru et al.) considerably enhance CO-stripping by synergistic oxidation (Pt-COads + 2 M−OHads → Pt + 2 M + H2O + CO2). However, these M materials do not presently attain the optimum CO-stripping efficiency and lack screening procedures, thus their durability falls well short of DMFC requirements. Here, we generalize the relationship between the M−OHads generation ability and Pt-COads effect by examining the OER activity and MOR durability. This allows us to screen ideal M materials, ensures CO-stripping efficiency, and helps in identifying the intrinsic OER mechanism to the MOR durability. A Pt-modified 3D micro-flower-shaped layered double hydroxides (NiFe-LDH) was designed in this study. Under the modification of OER activity, the MOR catalytic mass activity of Pt/NiFe-LDH reaches 3288.7 mA mg-1Pt. More importantly, because of the NiFe-LDH synergy, the CO-poisoned Pt could be reactivated using a simple CV method, and the reactivated Pt/NiFe-LDH could maintain four times or more CA tests with low activity loss. Such a type of M materials screening approach focuses on not only Pt/NiFe-LDHs reported in this work but also the design of Pt/Pd-based MOR catalysts on DMFCs.