Chemical Surface Grafting of Pt Nanocatalysts for Reconciling Methanol Tolerance with Methanol Oxidation Activity

Abstract

A conceptual challenge toward more versatile direct methanol fuel cells (DMFCs) is the design of a single material electrocatalyst with high activity and durability for both oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). This requires to conciliate methanol tolerance not to hinder ORR at the cathode with a good MOR activity at the anode. This is especially incompatible with Pt materials. We tackled this challenge by deriving a supramolecular concept where surface-grafted molecular ligands regulate the Pt-catalyst reactivity. ORR and MOR activities of newly reported Ptcalix[4]arenes nanocatalysts (Pt CF 3 NPs/C) are compared to commercial benchmark PtNPs/C. Pt CF 3 NPs/C exhibit a remarkable methanol tolerance without losing the MOR reactivity along with outstanding durability and chemical stability. Beyond designing single-catalyst material, operable in DMFC cathodic and anodic compartments, the results highlight a promising strategy for tuning interfacial properties.

Impact of controlling the crystallinity on bifunctional electrocatalytic performances toward methanol oxidation and oxygen reduction in binary Pd–Cr solid solution

“…6(d)), there is no evident change in the ORR activity using Pd–Cr_350 °C-modified electrode after the injection of methanol in the solution, as proved by nearly the same RDE voltammograms in both O 2 -saturated 0.1 M KOH with and without methanol; however, the Pt/C were highly affected by the presence of methanol which was highly susceptible to methanol poisoning. 62,63 This result, therefore, demonstrated that Pd–Cr_350 °C is an excellent methanol tolerant cathodic catalyst for alkaline oxygen reduction. In addition, the alkaline ORR activity of Pd–Cr_350 °C revealed a remarkable achievement, exhibiting a comparable or even superior level of performance when compared to state-of-the-art Pd-based nanomaterials that have been previously reported (Table S1†).…”

Facile one-step synthesis of mesoporous Pt-based alloy nanospheres for ethanol electrooxidation

“…20 Despite the above successful preparation of porous Pt nanomaterials, the construction of Pt catalysts with well-controlled dimensions and morphologies continues to be highly challenging. 21 There is thus a strong desire to develop new options to overcome the tediousness and complexities of these synthetic methods. In addition, the development of electrocatalysts displaying good reactivity and robust reliability at low PGM loading to afford high performance in particular applications is also regarded as an urgent need.…”