Sonoelectrochemical Synthesis of Proton Exchange Membrane Water Electrolyzer (PEMWE) Electrocatalysts

Abstract

The publication of ‘The use of ultrasound for the fabrication of fuel cell materials’ in the International Journal of Hydrogen Energy in 2010 [1] triggered an international interest in the use of power ultrasound (20 kHz – 1 MHz), sonochemistry (the use of ultrasound in chemistry) and sonoelectrochemistry (the use of ultrasound in electrochemistry) [2-4] for the synthesis of energy materials and useful gases [5]. This is due to the fact that these techniques allow the generation of nano-energy materials of controlled sizes, shapes and morphologies in a one-pot synthetic approach [6]. Furthermore, these methods do not require intensive labour and the use of excess amounts of toxic and environmentally hazardous solvents that are often used in conventional chemical methods. In 2009, Zin, Pollet and Dabalà published the first paper in the literature highlighting the synthesis of platinum (Pt) nanoparticles from aqueous solutions using sonoelectrochemistry [7]. Recently, Karousos et al. [8] showed that the high surface area Vulcan XC-72 carbon black (CB) substrate can be decorated with sonoelectrochemically produced Pt in a one-pot-one-step process by combining galvanostatic pulsed electrodeposition and power ultrasound (20 kHz). In this present study, IrO2 nanoparticles were synthesized sonochemically and sonoelectrochemically at room temperature in a three-electrode set up using a ultrasonicating GC (glassy carbon) working electrode or sonoelectrode generating very short applied current pulses (a few ms) triggered and followed immediately by short ultrasonic pulses (a few ms at 24 kHz). The Oxygen Evolution Reaction (OER) activity of the IrO2 electrocatalyst nanoparticles were evaluated ex-situ via cyclic voltammetry (CV) and linear sweep voltammetry (LSV), and the physical properties of the IrO2 electrocatalyst nanoparticles were evaluated via X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS). The data were compared to commercial catalysts and those obtained by other methods [9]. B.G. Pollet. The use of ultrasound for the fabrication of fuel cell materials, Int. J. Hydrogen Energy 22 (2010) 1039–1059.B.G. Pollet, M. Ashokkumar (Eds), B.G. Pollet, M. Ashokkumar, Introduction to ultrasound, Sonochemistry and Sonoelectrochemistry, SpringerBriefs: Berlin, Germany (2019) in press.B.G. Pollet (Ed), Power ultrasound in electrochemistry: from versatile laboratory tool to engineering solution, John Wiley & Sons, Hoboken, NJ, USA (2012) ISBN: 978-0-470-97424-7.B.G. Pollet, A short introduction to Sonoelectrochemistry. Electrochem. Soc. Interface 27 (2018) 41–4.Md.H. Islam, O.S. Burheim, B.G. Pollet, Sonochemical and sonoelectrochemical production of hydrogen, Ultras. Sonochem. 51 (2019) 533-555.M.T.Y. Paul, Md.H. Islam, O.S. Burheim, B.G. Pollet, Recent development in sonoelectrochemical synthesis of nanomaterials, Ultrason. Sonochem., submitted (2019).V. Zin, B.G. Pollet, M. Dabalà. Sonoelectrochemical (20kHz) production of platinum nanoparticles from aqueous solutions, Electrochim. Acta 54(28) (2009) 7201-7206.D.S. Karousos, K.I. Desdenakis, P.M. Sakkas, G. Sourkouni, B.G. Pollet, C. Argirusis. Sonoelectrochemical one-pot synthesis of Pt–carbon black nanocomposite PEMFC electrocatalyst. Ultrason. Sonochem. 35(B) (2017) 591-597.C.Felix, B.J. Bladergroen, V. Linkov, B.G. Pollet, S. Pasupathi, Ex-situ electrochemical characterization of IrO2 synthesized by a modified Adams Fusion method for the oxygen evolution reaction, Catalysts 2019, 9, 318; doi:10.3390/catal9040318