Analysis of hydroxyl radical formation in a gas‐liquid electrical discharge plasma reactor utilizing liquid and gaseous radical scavengers. Issue 8 (16th March 2017)

• Record Type: Journal Article
• Authors: Hsieh, Kevin C.; Wandell, Robert J.; Bresch, Stefan; Locke, Bruce R.
• Is Part Of: Plasma processes and polymers. Volume 14:Issue 8(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-03-16
• Subjects: gas‐liquid plasma discharge -- hydroxyl radicals -- non‐thermal plasma -- radical scavengers -- radicals; Plasma polymerization -- Periodicals; Plasma-enhanced chemical vapor deposition -- Periodicals; Plasma chemistry -- Periodicals
• DOI: 10.1002/ppap.201600171
• Languages: English
• ISSNs: 1612-8850

Abstract

Abstract : Production rates of hydroxyl radical ( OH) formation in a gas‐liquid plasma discharge reactor with pure water and argon were quantified using gas (carbon monoxide: CO) and liquid (ethanol) radical scavengers. The major oxidation products were acetaldehyde from ethanol and carbon dioxide (CO2 ) from CO. Total OH production rates were estimated from the OH required to form these products and hydrogen peroxide (H2 O2) . Ethanol completely depleted H2 O2 suggesting that it is formed in or near the plasma‐liquid interface. OH production rates were higher with CO, and CO had a smaller effect on H2 O2 suggesting additional OH is available for other reactions at the plasma‐gas interface. The best case total OH production was approximately 25% of the thermodynamic limit for water dissociation based upon measured CO2 from CO. Abstract : A pulsed electrical discharge forming a plasma channel that propagates along the interface between an argon gas phase and a liquid water film generates hydroxyl radicals that can react with compounds from both the gas and liquid. These chemical probe reactions are used to determine the maximum efficiency for hydroxyl radical generation in this system.