Influence of High Voltage Needle Electrode Material on Hydrogen Peroxide Formation and Electrode Erosion in a Hybrid Gas–Liquid Series Electrical Discharge Reactor

Abstract

Formation rates of hydrogen peroxide and electrode erosion rates for a range of different electrode materials were determined in a gas-liquid pulsed electrical discharge reactor with a high voltage electrode needle in the liquid and a ground electrode suspended in the gas over the liquid. It was found that the H 2 O 2 formation rates and efficiencies did not depend on the electrode material. Electrode erosion from lowest to highest followed the series: nickel chromium, thoriated tungsten, diamond-coated tungsten, stainless steel, tungsten carbide and tungsten copper alloy. Smooth crater-like morphology was found for nickel chromium, titanium and tungsten carbide and a much finer surface structure with small protrusions for the tungsten, tungsten copper and the copper. Doubling the electrode diameter lead to an increase in the H 2 O 2 formation per eroded length by a factor of three but it also decreased the energy efficiency yield of H 2 O 2 by more than 20%.

Unusual catalytic effects of iron salts on phenol degradation by glow discharge plasma in aqueous solution

“…It is noted that the present energy costs for phenol removal is close to those reported in pulsed corona reactor [22]. However, the energy cost for H 2 O 2 formation in the present study is about twofold to those in pulsed corona discharge (about 8.0 nmol/J) [19,20]. Therefore, the investigation of Fenton's reaction is of great importance in GDP.…”

“…In this work, the energy efficiency for phenol degradation (G phenol ) and for H 2 O 2 formation (G H 2 O 2 ) [19,20] can be defined as follows:…”

Effect of temperature on methylene blue decolorization in aqueous medium in electrical discharge plasma reactor

“…5 However, the rate and efficiency of H 2 O 2 formation is not necessarily dependent on the electrode material. 6 Another efficient strategy which can be applied to enhance the generation of active species and the consequent pollutant degradation is the combination of non-thermal plasma reactors with different advanced oxidation processes, such as ozonation, 7 TiO 2 photo-catalysis, [8][9][10] alumina and silica gel (resulting in adsorption) 11 and homogeneous (e.g., Fe…”

Chemical and Physical Characteristics of Pulsed Electrical Discharge Within Gas Bubbles in Aqueous Solutions

“…As a result of these large electric fields, the issue of electrode erosion associated with direct liquid phase electric discharge has been reported [36,37]. Changing the material did not resolve the needle erosion problem due to the high plasma temperature [37].…”

“…Changing the material did not resolve the needle erosion problem due to the high plasma temperature [37]. Also, the rate of erosion of the electrodes increases in high conductivity solutions which occur in many chemical and biological applications.…”