Item

Abstract

As the anode reaction of anion exchange membrane fuel cells (AEMFCs),} hydrogen oxidation reaction (HOR) has attracted great attention{,} however{,} suffers from the low kinetics in alkaline condition. In this work{,} we demonstrate that the strong synergy at the heterointerface of hexagonal close-packed (hcp) and face-centered cubic (fcc) phase of Ru-Sn nanoflowers can greatly contribute to accelerate the alkaline HOR kinetics and strengthen the resistance to CO{,} a common poison present in industrially produced H2. Experimental observations{,} in-situ characterizations{,} and theoretical calculations suggest that the interfacial synergy{,} linked to the ratio of fcc/hcp phase{,} can modulate the adsorption ability of H{,} weaken the binding strength to CO{,} and reduce the energy barrier for CO oxidation. Impressively{,} the optimal fcc0.42 Ru-Sn/C exhibits a mass activity and specific activity of 4.9 A mgRu−1 and 6.7 mA cmECSA−2 at 50 mV{,} respectively{,} which is 9.8 time and 7.4 time higher than those of hcp Ru/C{,} surpassing commercial Pt/C and other recently reported catalysts for HOR. Moreover{, the fuel cell assembled with fcc0.42 Ru-Sn/C exhibits a power peak density (PPD) of 12.46 W mgRu−1.