Impact of sp 2 carbon material species on Pt nanoparticle-based electrocatalysts produced by one-pot pyrolysis methods with ionic liquids.

Pt-nanoparticle-supported graphene nanoplatelets (Pt/GNPs) and multiwalled carbon nanotube composite (Pt/MWCNTs) electrocatalysts for the oxygen reduction reaction (ORR) can be prepared using a one-pot method through the pyrolytic decomposition of the platinum precursor, platinum(ii) bis(acetylacetonate) (Pt(acac) 2 ) in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([C 4 mim][Tf 2 N]) or N , N , N -trimethyl- N -propylammonium bis(trifluoromethanesulfonyl)amide ([N 1,1,1,3 ][Tf 2 N]) ionic liquids (ILs) with the target sp 2 carbon support. In this one-pot pyrolysis method, which does not require any reagents to reduce Pt metal precursors or stabilize Pt nanoparticles, Pt nanoparticles are readily immobilized onto the sp 2 surface by a thin IL layer formed at the interface, which can work as a binder. We used three types of sp 2 carbon materials with different geometric shapes (graphene nanoplatelets with <3 (GNPs-3) and 18-24 layers (GNPs-20) and multiwalled carbon nanotubes (MWCNTs)) to investigate Pt nanoparticle formation and anchoring. All the electrocatalysts, especially Pt/MWCNTs, showed higher durability than the commercial catalyst owing to the combined effect of the IL binder and sp 2 carbon materials. Our findings strongly suggest that the original carbon surface properties are also an important factor for creating high-performance ORR electrocatalysts.