High-temperature heterogeneous catalysis in platinum nanoparticle – molten salt suspensions

Abstract

Suspensions of platinum nanoparticles (PtNPs) were formed in molten LiCl–LiBr–KBr via thermal decomposition of H₂PtCl₆, and subsequently evaluated for thermal stability and CO oxidation activity. Significant nanoparticle (NP) aggregation was observed above 500 °C, and the heat capacity of the melt with PtNPs was 47% higher than the salt alone, further increasing with NP concentration. CO oxidation was observed when PtNPs were present in the melt, which, together with measured changes in surface tension, support the hypothesis that gas–solid catalysis at the gas–nanoparticle-melt interface is indeed possible, opening up a new approach for heterogeneous catalysis.