Chemical Action of Glow Discharge Electrolysis on Ethanol in Aqueous Solution

Abstract

The action of anodic glow discharge electrolysis (gde) on ethanol in neutral aqueous phosphate buffer gave acetaldehyde, butan-2,3-diol, hydrogen peroxide, and acid. The yields of these products were found to vary substantially with the presence or absence of oxygen and in particular with oxygen flow rate and substrate concentration. A mechanism has been proposed for the reaction of substrate in both the presence and absence of oxygen.Ethanol vapor and water vapor, over aqueous ethanol solutions, were subjected to glow discharge electrolysis (gde).by Klemenc (1), who examined the gaseous products only. Gde has been performed also on pure methanol (2), with a variety of supporting electrolytes; products were a complex mixture of simple breakdown species. Scholes and co-workers (3) studied the effects of x-rays (200 kV) on ethanol in aqueous solution and found that in the presence of oxygen the products were hydrogen peroxide and acetaldehyde alone. Using deaerated solutions they found acetaldehyde and butan-2, 3-diol, with traces of hydrogen peroxide (under acid conditions). Seddon and Allen (4) studied the hydrogen yields arising from the 7-radiolysis of neutral aqueous solutions of ethanol both in the presence and in the absence of oxygen. Recently Schultze and Schulte-Frohlinde (5) studied the effects of the v-irradiation of dilute aqueous ethanol under a gaseous mixture of oxygen and nitrous oxide. The products were acetaldehyde, acetic acid, glycolaldehyde, ethylene glycol, and hydrogen peroxide.A careful study was made of the total yields in the present work to determine the ultimate fates of all the radicals generated by gde: As will be seen, we have accounted for G(OH) in terms of our products. We also studied carefully the proportion cf acetaldehyde and hydrogen peroxide since this gives valuable evidence about the reaction possibilities, and we were able to show that in gde under oxygen flow rates high enough to scavenge all the 1-hydroxyethyl radicals (CHsCHOH) and at ethanol concentrations high enough to scavenge all the hydroxyl radicals, there is a particularly straightforward interaction between the 1-hydroxyethylperoxyl radicals (CH3 CI-IOH) 02 yielding acetaldehyde and hydrogen peroxide in 2:1 proportions. ExperimentalThe ethanol solutions were prepared by dissolving the correct amounts of pure absolute ethanol in neutral phosphate buffer solution, except for runs on acid determination under oxygen where very dilute alkali was used. The solutions after gde were analyzed for hydrogen peroxide (6), acetaldehyde (7), butan-2, 3-diol, and acid. since these compounds were the products of x-irradiation of phosphate buffer/ ethanol solutions (3). Other species sought by the wor]~ers who used x-irradiation were acetic acid, ethylene glycol, glycolaldehyde, ethyl hydroperoxide, diethyl peroxide, peracetic acid, and ethyl acetate, but no evidence was found for any of these. The acetaldehyde determination is essentiM]y co]orimetric: the absorbance, which declined rapidly, was recorded as Key words: glow disc...

Investigation of the opportunity for increasing the yield of hydrogen peroxide in plasma-solution systems

“…The action of the glowing discharge on the solution of ethyl alcohol at reduced pressure has been investigated in the work of Almubarak and Wood [13]. The main products of the interaction were acetaldehyde, hydrogen peroxide, and 2,3-butanediol.…”

Electrohydraulic Discharge and Nonthermal Plasma for Water Treatment

“…The synthesis and degradation of many organic compounds, including a range of amino acids, have been studied in glow discharge electrolysis and the related contact glow discharge electrolysis, whereby both electrodes are submerged in the liquid phase. ,− ,,− These studies have developed from the pioneering work of Miller, involving the problem of the chemical origin of life under conditions simulating the early atmosphere of the Earth. Miller used both gas-phase silent discharges and high-frequency AC spark discharges in contact with water surfaces to demonstrate that more-complex bio-organic compounds, including many amino acids, could be produced by nonbiological means.…”

Scavenging Effects of Aliphatic Alcohols and Acetone on H• Radicals in Anodic Contact Glow Discharge Electrolysis: Determination of the Primary Yield of H• Radicals

“…4 show further that the liquid-phase yield (H 2 ) L rises with increasing concentrations of an additive and finally approaches a limiting value. A similar concentration effect on the yield of H 2 was observed during radiolysis of pure or aqueous solutions of aliphatic alcohols and carbonyl compounds having hydrogen on their a-carbon atom [25,26] and also during glow discharge electrolysis (GDE) of aqueous ethanol and methanol solutions [27,28]. It may be noted further that like radiolysis and glow discharge electrolysis (GDE), anodic CGDE of alcohol and acetone solutions gives rise to O 2 and CO with minor quantities of CO 2 and CH 4 besides H 2, the main gaseous product e.g.…”