Targeted Growth of Pt on 2D Atomic Layers of Ni-Al Hydroxide: Assembly of the Pt/Exfoliated Ni-Al Hydroxide sheet/Graphene Composite as Electrocatalysts for Methanol Oxidation Reactions

Abstract Platinum/exfoliated Ni-Al layered double hydroxides (LDHs)/reduced graphene oxide (rGO) ternary composite (Pt/LDH/rGO) as a highly active electrocatalyst for efficient methanol oxidation reactions (MORs) was fabricated by a facile self-assembly method with controlling electrostatic interactions between precursors. The introduction of 2D atomic layers of Ni-Al LDH sheet is of vital importance for the removal of poisonous carbonaceous intermediates on Pt surface in the methanol oxidation process due to its outstanding performance in dissociative absorption of water molecules. Structural characterizations show that the active Pt particles with a size range of 3–5 nm are uniformly dispersed on the LDH 2D platelets and the rGO sheet acts as a conductive supporter for the Pt/LDH composites. An in-situ reactivation process for recovery of Pt activity is proposed in virtue of different working potential ranges between Ni-Al LDH and Pt in alkaline solution. Under periodic reactivation, the activity of Pt can be fully recovered without renewing the reaction solution. Electrochemical tests show that the as-prepared ternary composite exhibits better activity and durability towards MOR than the commercial Pt/C catalyst.