title: Catalytic reduction of 4-nitrophenol over Ni-Pd nanodimers supported on nitrogen-doped reduced graphene oxide.
abstract: Catalytic reduction of toxic 4-nitrophenol to 4-aminophenol over magnetically recoverable nanocatalysts has attracted much attention. Herein, we report a Ni-Pd/NrGO catalyst through the growth of Ni-Pd nanodimers (NDs) on nitrogen-doped reduced graphene oxide (NrGO). The Ni-Pd NDs show a heterogeneous nanostructure with Ni and Pd subparts contacting with each other, remarkably different from the frequently-observed core/shell nanoparticles (NPs) or nanoalloy. The formation of Ni-Pd NDs follows an initial deposition of Pd NPs on the graphene and in-situ catalytic generation of Ni subparts over the newly-generated Pd NPs. The resulting Ni-Pd/NrGO exhibits a superior catalytic activity towards the reduction of 4-nitrophenol at room temperature with a high rate constant (3400s-1g-1) and a low activated energy (29.1kJmol-1) as compared to unsupported Ni-Pd NDs and supported monometallic catalysts. The conversion rate of 4-NP is calculated to be 99.5% and the percent yield (%) of 4-AP is as high as 99.1%. A synergistic catalysis mechanism is rationally proposed, which is ascribed to the electronic modification of Ni-Pd metals due to the strong metal/support interaction (SMSI) effect as well as the electron transfer between Ni and Pd. The hybrid catalyst shows soft ferromagnetic properties and can be magnetically separated and recycled without obvious loss of activity.
authors: College of Chemistry and Chemical Engineering, Wuhan Textile University, Wuhan 430073, People⿿s Republic of China; Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA. Electronic address: liulj@wtu.edu.cn.
authors: Lijun
authors: L
authors: Liu
authors: College of Chemistry and Chemical Engineering, Wuhan Textile University, Wuhan 430073, People⿿s Republic of China.
authors: Ruifen
authors: R
authors: Chen
authors: College of Chemistry and Chemical Engineering, Wuhan Textile University, Wuhan 430073, People⿿s Republic of China.
authors: Weikai
authors: W
authors: Liu
authors: Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors: Jiamin
authors: J
authors: Wu
authors: Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA. Electronic address: gaod@pitt.edu.
authors: Di
authors: D
authors: Gao
keywords: Nanodimers; Nickel; Palladium; Synergistic catalysis; p-Nitrophenol