摘要

We demonstrated that acetylene was a unique reducing agent for aqueous synthesis of ultrasmall Pt nanoparticles (NPs) supported on carbon nanotube (CNT) with high stability. Multiple techniques including X-ray absorption fine structure (XAFS) were employed to fully characterize this Pt catalyst. The in-situ generated olefins from acetylene closely wrapped the Pt NPs, and turned into a very thin carbon shell in the subsequent calcination step. The carbon shell not only endowed the Pt NPs with extraordinary thermal stability, but also significantly improved the catalytic selectivity in hydrogenation of halogenated nitrobenzene by eliminating the dehalogenation reaction. Also, the acetylene-mediated preparation method is readily scalable due to its convenience and environmental friendliness.