Metal Organic Framework-Modified Graphene-Based Catalyst for Oxygen Reduction Reaction

Abstract

Nitrogen-doped graphene (N-G) is one of promising non-platinum group metal (non-PGM) catalysts for the oxygen reduction reaction (ORR). In this research, we investigated new N-G catalysts which are modified by the metal-organic framework (MOF), to enhance the electrochemical performance of N-G catalysts. The new MOF-modified N-G (N-G/MOF) catalysts with microporous structures are successfully synthesized by high energy nano wet ball milling methods with N-G and ZIF-8. The physical and chemical properties of new synthesized N-G/MOF catalysts are characterized several characterization methods such as XPS, XAS, SEM-EDS, TEM, XRD, BET and RRDE. The result shows that new microporous structures in NG/MOF catalysts were formed at 350 RPM which are totally different from structures of N-G and ZIF-8, and BET surface area is increased from 25 to 1103 (m 2 /gram). However, at 650 RPM the new microporous structures are suppressed to have no significant effect on the N-G structure. The ongoing research activities are trying to understand the synthesis reaction mechanism and to study the control of the synthesis mechanism through chemical and electrochemical characterizations of N-G/MOF catalysts. This research shows that the ZIF-8 could be a promising additive to modify physical, chemical, and catalytic performances of N-G catalysts. The successful accomplishment of the new N-G/MOF catalysts will provide the substantial way to the cost-effective and fuel-efficient energy conversion system.