Abstract ▼ AI-Helper

Graphene has been modified with palladium nanoparticles (NPs) to develop high performance catalysts for C-C coupling reactions. In this research, graphite oxide (GO) sheets were exfoliated and oxidized from graphite powder and impregnated with metal precursors to prepare Pd2+/GO. To understand how t...

Graphene has been modified with palladium nanoparticles (NPs) to develop high performance catalysts for C-C coupling reactions. In this research, graphite oxide (GO) sheets were exfoliated and oxidized from graphite powder and impregnated with metal precursors to prepare Pd2+/GO. To understand how the oxidative states and morphological structures of Pd-graphene nanocomposites influence on chemical reactions, Pd2+/GO were heated to be reduced in H2 environment and oxidized in O2 environment ranging from 100℃ to 500 ℃ to obtain Pd NPs on graphene (Pd/G) and PdO NPs on graphene oxide (PdO/GO), respectively. TEM images show that the NPs are distributed quite uniformly on both the graphene and graphene oxide sheets without obvious aggregation. The electronic and chemical structures of Pd-graphene nanocomposites were investigated using FT-IR, XRD, XAFS, and XPS. In C-C coupling reaction, the Pd NPs of Pd/G were pretty much aggregated and the catalytic activities continue to decrease in recycling whereas PdO NPs of PdO/GO were not aggregated and the catalytic activities were retained up to sixth recycling. We found that the particle sizes are a more critical factor than Pd oxidation state in organic reaction and the GO is one of the very important factors in catalytic applications.

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