Ni–WC/C nanocluster catalysts for urea electrooxidation

• Published in: Journal of power sources Vol. 264; pp. 282 - 289
• Main Authors: Wang, Lu, Li, Mingtao, Huang, Zhiyu, Li, Yingming, Qi, Suitao, Yi, Chunhai, Yang, Bolun
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.10.2014; Elsevier
• Subjects: Anodizing; Catalysis; Catalysts; Catalysts: preparations and properties; Chemistry; Electrochemistry; Electrodes; Electrooxidation of urea; Exact sciences and technology; General and physical chemistry; Miscellaneous (electroosmosis, electrophoresis, electrochromism, electrocrystallization, ...); Nanostructure; Nanostructure electrocatalysts; Nickel; Synergistic effect; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Tungsten carbide; X-ray photoelectron spectroscopy; X-rays; Tungsten carbide; Nanostructure electrocatalysts; Synergistic effect; Electrooxidation of urea; Nanocluster; Electrocatalysts; Transition metal; Nanostructure; Synergism; Electrocatalysis; Urea; Tungsten Carbides; Ureas; Nickel; Oxidation; Catalyst
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2014.04.104

A nanocluster Ni–WC/C electrocatalyst is prepared through a sequential impregnation method and is used for the urea electrooxidation in alkaline conditions. The micro-morphology, lattice parameter, composition and surface states of Ni–WC/C particles are determined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) and X-ray photoelectron spectrometry (XPS) analysis. The electrooxidation activity and stability of the Ni–WC/C catalyst are also investigated by cyclic voltammograms and chronoamperograms. Characterization results indicate that the Ni nanoclusters are uniformly distributed on the WC/C framework, and the Ni–WC/C catalyst shows high electrocatalytic activity and stability for urea electrooxidation. The maximum current density at the Ni–WC/C electrode is almost 700 mA cm−2 mg−1 which is one order of magnitude higher than that at the Ni/C electrode, and the steady current density at the Ni–WC/C electrode is also markedly improved. Furthermore, the ESA values and XPS spectra indicate that the enhanced performance of the Ni–WC/C catalyst could be attributed to the structure effect and electron effect between nickel and tungsten carbide. [Display omitted] •The Ni–WC/C catalysts were prepared successfully by a simple impregnation method.•The nickel particles were grown on the WC/C framework in clusters with nanoscale.•Tungsten carbide promotes nickel to more active sites for urea electrooxidation.•Ni–WC/C nanoclusters show superior catalytic activity for urea electrooxidation.