Functionalized Carbon Nanomaterial Supported Palladium Nano-Catalysts for Electrocatalytic Glucose Oxidation Reaction

Palladium nanoparticles (nPd) are grown on six carbon nanomaterials with different functionalities by one-pot, high-pH polyol reduction of PdCl2. The nanomaterials include pristine multi-walled carbon nanotubes (pMWCNT), carboxylated MWCNT (cMWCNT), amine-modified MWCNT (nMWCNT), hydroxyl-modified MWCNT (oMWCNT), XC72 carbon black (XC72), and carboxylated graphene (cGraphene). The effects of the carbon functionality on Pd-catalyzed glucose oxidation reaction (GOR) in an alkaline medium are studied. From the experimental data of X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and transmission electron microscopy (TEM), it reveals that nPds with a particle size ranging from 4.5 nm to 7.4 nm are grown on carbon nanomaterials with a weight loading percentage from 11.1% to 18.6%. Cyclic voltammetry (CV), linear sweep voltammetry (LSV), Tafel analysis, and chronoamperomtry (CA) are used to compare the electrochemical active surface area (ECSA), GOR onset potential, GOR peak current density, Tafel slope, poisoning rate, and cycling stability between the six nPd/C electrocatalysts for GOR. It is found that nPd grown on a functionalized carbon nano-support had better GOR performance than that grown on pMWCNT. Compared to nPd/pMWCNT, nPd/cMWCNT shows a 6.2-fold higher peak current density (5.6 mA cm(-2)) and a 100 mV lower over-potential (-0.55 V vs. Hg/HgO) for GOR. Besides, the data are among the best for nPd-catalyzed GOR reported to date. (C) 2014 Elsevier Ltd. All rights reserved.