Anti-CO Poisoning FePtRh Nanoflowers with Rh-Rich Core and Fe-Rich Shell Boost Methanol Oxidation Electrocatalysis

Introducing oxophilic metals into Pt-based alloy catalysts can effectively alleviate the poisoning by CO intermediates (CO*) during methanol oxidation reactions (MOR). However, excessive oxophilic metals on the surface of catalysts tend to form thermodynamically stable carbonyl compound-like structures, occupying electrocatalytically active sites, which is not conducive to the enhancement of catalytic activity. Herein, a kind of surface segregated FePtRh nanoflowers for effectively eliminating the CO* poisoning during MOR electrocatalysis is presented. The FePtRh nanoflowers are constituted by the Rh-rich core and Fe-rich shell. The optimized Fe₂₁Pt₆₆Rh₁₃/C shows a high mass activity of 3.90 A mg_Pt⁻¹ and a specific activity of 4.85 mA cm⁻². It is confirmed that the electron transfer from Pt to Rh or Fe atoms is beneficial for the higher anti-CO poisoning ability, which mainly originate from the alloying of Rh atoms and surface-segregated structures. Density functional theory calculations reveal the decreased electrons adsorbed by CO* on both Pt–Pt bridge sites and top sites weakens the strong adsorption energy between Pt atoms and CO* intermediates. The optimal nanoflowers also show excellent performance toward ethanol oxidation reaction (EOR) with a high mass activity of 2.76 A mg_Pt⁻¹ and the enhanced anti-CO poisoning ability, as well as the improved stability.