Coauthored Publications with: Thanasekaran

Journal Article

Veerakumar, P, Salamalai K, Thanasekaran P, Lin K-C.  2018.  Simple Preparation of Porous Carbon-Supported Ruthenium: Propitious Catalytic Activity in the Reduction of Ferrocyanate(III) and a Cationic Dye. ACS Omega. 3:12609-12621., Number 10 AbstractWebsite

The present study involves the synthesis, characterization, and catalytic application of ruthenium nanoparticles (Ru NPs) supported on plastic-derived carbons (PDCs) synthesized from plastic wastes (soft drink bottles) as an alternative carbon source. PDCs have been further activated with CO2 and characterized by various analytical techniques. The catalytic activity of Ru@PDC for the reduction of potassium hexacyanoferrate(III), (K3[Fe(CN)6]), and new fuchsin (NF) dye by NaBH4 was performed under mild conditions. The PDCs had spherical morphology with an average size of 0.5 μm, and the Ru NP (5 ± 0.2 nm) loading (4.01 wt %) into the PDC provided high catalytic performance for catalytic reduction of ferrocyanate(III) and NF dye. This catalyst can be recycled more than six times with only a minor loss of its catalytic activity. In addition, the stability and reusability of the Ru@PDC catalyst are also discussed. Copyright © 2018 American Chemical Society.
Veerakumar, P, Thanasekaran P, Lin K-C, Liu S-B.  2017.  Well-dispersed rhenium nanoparticles on three-dimensional carbon nanostructures: Efficient catalysts for the reduction of aromatic nitro compounds. Journal of Colloid and Interface Science. 506:271-282. AbstractWebsite

Rhenium nanoparticles (ReNPs) supported on ordered mesoporous carbon (OMC) as a catalyst (Re/OMC) through a solvent-evaporation induced self-assembly (ELSA) method were prepared. The synthesized heterogonous catalyst was fully characterized using X-ray diffraction, field emission transmission electron microscopy, N2 sorption, metal dispersion, thermogravimetric analysis, Raman, Fourier-transform infrared, and X-ray photon spectroscopies. In addition, the catalyst was applied to reduce the aromatic nitro compounds (ANCs) for the first time in aqueous media and the reactions were monitored by following the intensity changes in the UV–vis absorption spectra with respect to time. This method provides the advantages of obtaining a high rate constant (k), green reaction conditions, simple methodology, easy separation and easy workup procedures. Moreover, the catalyst can be easily recovered by centrifugation, recycled several times and reused without any loss of activity. The higher activity of this catalyst was attributed to higher dispersion and smaller particle size of ReNPs as observed from FE-TEM and XRD results. © 2017
Veerakumar, P, Thanasekaran P, Lin K-C, Liu S-B.  2017.  Biomass Derived Sheet-like Carbon/Palladium Nanocomposite: An Excellent Opportunity for Reduction of Toxic Hexavalent Chromium. ACS Sustainable Chemistry and Engineering. 5:5302-5312., Number 6 AbstractWebsite

Palladium nanoparticles (Pd NPs) immobilized on a garlic skin-derived activated carbons (GACs) is reported. The morphology, structure, surface compositions, and textural properties of the GACs and Pd@GAC catalyst were investigated by a variety of physicochemical characterization techniques, which revealed a dispersion of Pd NPs with average particle size of ca. 21 nm on sheet-like graphitized GACs with surface areas and pore volumes as high as 1836 m2 g-1 and 0.89 cm3 g-1, respectively. As a result, the Pd@GAC with a Pd loading of ca. 1-2 wt% exhibited superior activity for catalytic reduction of toxic Cr(VI) to Cr(III) surpassing most metal-based catalysts reported in the literature. As evidenced by a comprehensive UV-vis spectrophotometric study, the eco-friendly Pd@GAC catalyst reported herein, which can be facilely prepared with biowaste feedstocks, also showed excellent catalytic performances for efficient reduction of Cr(VI) with extraordinary stability and recyclability over at least five repeated catalytic test cycles. © 2017 American Chemical Society.
Veerakumar, P, Thanasekaran P, Lu K-L, Lin K-C, Rajagopal S.  2017.  Computational Studies of Versatile Heterogeneous Palladium-Catalyzed Suzuki, Heck, and Sonogashira Coupling Reactions. ACS Sustainable Chemistry and Engineering. 5:8475-8490., Number 10 AbstractWebsite

This perspective focuses on the mechanistic insights and complexity, which are difficult to acquire from pure experimental techniques, of the computational studies of Pd-catalyzed Suzuki, Heck, and Sonogashira carbon-carbon bond-forming reactions. These reactions consist of three fundamental steps including oxidative addition (OA), transmetalation (TM), and reductive elimination (RE) for the generation of carbon-carbon bonds from the bond-forming reactions of aryl halides (R1X) and organometallic species (R2M). Computational studies of these coupling reactions allow us to understand specific reaction pathways in the analysis of OA (resolving the linkage between coordination number and selectivity in Suzuki reaction), TM (the function of the base in the Suzuki reaction and various mechanistic options in the Sonogashira reaction), and RE (way of efficient β-hydride elimination in the Heck reaction). In addition, the reaction pathways and complexities in the full catalytic cycle of each reaction along with the future perspective are also discussed. © 2017 American Chemical Society.
Veerakumar, P, Panneer Muthuselvam I, Thanasekaran P, Lin K-C.  2018.  Low-cost palladium decorated on: M -aminophenol-formaldehyde-derived porous carbon spheres for the enhanced catalytic reduction of organic dyes. Inorganic Chemistry Frontiers. 5:354-363., Number 2 AbstractWebsite

We report the use of palladium nanoparticles (Pd NPs) immobilized on m-aminophenol/formaldehyde resin (APF)-derived porous carbon spheres (Pd@PCS) as heterogeneous catalysts for the reduction of organic dyes. The morphology, structure, surface compositions, and textural properties of PCS and the Pd@PCS catalyst were characterized fully to document the excellent catalytic efficiency of Pd@PCS composites. Pd NPs of mean particle size ca. 12 ± 0.8 nm were highly dispersed on the surface of PCSs, and possessed surface area and pore volume as high as 896.3 m2 g-1 and 0.934 cm3 g-1, respectively. Prepared catalysts were applied to the reduction of various organic dyes; high catalytic activity towards crystal violet, eosin yellow and sunset yellow was observed. More importantly, the catalysts could be recovered readily, and reused many times with good stability. Therefore, the robust material utilized for the treatment of containing organic dyes could be used widely for environmental applications. © 2018 the Partner Organisations.