Facile Green Preparation of Rhodium Nanoclusters Supported Nano-Scaled Graphene Platelets for Sonogashira Coupling Reaction and Reduction of p-Nitrophenol

Catalysts

Gopiraman Mayakrishnan¹  Chung Ill Min¹  Kim Ick Soo²  Sana Ullah²  Ilangovan Andivelu³  Saravanamoorthy Somasundaram³ 

[1] Department of Crop Science, College of Sanghur Life Science, Konkuk University, Seoul 05029, Korea.;Nano Fusion Technology Research Group, Division of Frontier Fibers, Institute for Fiber Engineering (IFES), Interdisciplinary Cluster for Cutting Edge Research (ICCER), Shinshu University, Tokida 3-15-1, Ueda, Nagano Prefecture 386-8567, Japan;School of Chemistry, Bharathidasan University, Tiruchirappalli, Tamil Nadu 620-024, India;

关键词: grapheneplatelets;    rh-nanoclusters;    green preparation;    4-nitrophenol;    c–c coupling reaction;    reusability;   

DOI  :  10.3390/catal9110908

来源: DOAJ

【 摘 要 】

Rhodium nanoclusters were uniformly dispersed on nano-scaled graphene platelets by a simple ‘mix and heat’ method without using any toxic reagents. Distilled water was used to obtain the homogenous dispersion of Rh-nanoclusters on graphene platelets. The morphology of the resultant catalyst (Rh(0)NCs/GNPs) was studied by means of transmission electron microscope (TEM) and atomic force microscope (AFM) analyses. The X-ray photoemission spectroscope (XPS) result confirmed the metallic form of Rh-nanoclusters in Rh(0)NCs/GNPs. The crystalline property and the interaction between Rh-nanoclusters and graphene platelets (GNPs) were studied by means of XRD and Raman analysis. The Rh-loading in Rh(0)NCs/GNPs was confirmed by scanning electron microscope and energy dispersive spectroscope (SEM-EDS) and inductively coupled plasma-mass spectroscope (ICP-MS) analysis. After being optimized, the Rh(0)NCs/GNPs used as catalyst for the reduction of 4-nitrophenol with NaBH₄ and the Sonogashira coupling reaction between iodobenzene with phenylacetylene. To our delight, the Rh(0)NCs/GNPs showed excellent catalytic activity towards the reduction of 4-nitrophenol with an excellent turnover frequency (TOF) value of 112.5 min⁻¹. The k_app and k’ values were calculated to be 62.07 × 10⁻³ min⁻¹(0.002 mg of Rh(0)NCs/GNPs) and 31035 × 10⁻³ mg⁻¹ min⁻¹,respectively. Alike, under the optimal conditions, the Rh(0)NCs/GNPs gave the desired product, diphenylacetylene, in a good yield of 87% with 91% selectivity. The Rh(0)NCs/GNPs can be reused without significant loss in its catalytic activity.

【 授权许可】

Unknown