Ionic liquids as precursors for efficient mesoporous iron-nitrogen-doped oxygen reduction electrocatalysts

Angew Chem Int Ed Engl. 2015 Jan 26;54(5):1494-8. doi: 10.1002/anie.201409579. Epub 2014 Dec 10.

Abstract

A ferrocene-based ionic liquid (Fe-IL) is used as a metal-containing feedstock with a nitrogen-enriched ionic liquid (N-IL) as a compatible nitrogen content modulator to prepare a novel type of non-precious-metal-nitrogen-carbon (M-N-C) catalysts, which feature ordered mesoporous structure consisting of uniform iron oxide nanoparticles embedded into N-enriched carbons. The catalyst Fe(10) @NOMC exhibits comparable catalytic activity but superior long-term stability to 20 wt % Pt/C for ORR with four-electron transfer pathway under alkaline conditions. Such outstanding catalytic performance is ascribed to the populated Fe (Fe3 O4 ) and N (N2) active sites with synergetic chemical coupling as well as the ordered mesoporous structure and high surface area endowed by both the versatile precursors and the synthetic strategy, which also open new avenues for the development of M-N-C catalytic materials.

Keywords: heterogeneous catalysis; ionic liquids; iron; ordered mesoporous carbon; oxygen reduction reaction.