Plasma-Catalytic Decomposition of Phenols in Atmospheric Pressure Dielectric Barrier Discharge

Abstract

This study investigated the processes for the destruction of phenol and its derivatives (resorcin and pyrocatechol) in aqueous solutions under the action of an oxygen dielectric barrier discharge (DBD) at atmospheric pressure in the presence or absence of catalysts in the plasma zone. It was shown that the DBD had a high decomposition efficiency for phenol and its derivatives (up to 99%). Phenol was the most stable and pyrocatechol was the least. In a plasma-catalytic hybrid process, the effective rate constants for phenol, resorcin and pyrocatechol decomposition were 11, 4 and 2.5 times higher, respectively, than those for the DBD treatment without catalysts. The process also resulted in a 1.4, 1.6 and 1.2 times higher rate of carboxylic acid formation for phenol, resorcin and pyrocatechol, respectively. The fractional conversion into the respective carboxylic acids reached 56% for phenol and 68% for resorcin and pyrocatechol.

Influence of Temperature on Gas-Phase Toluene Decomposition in Plasma-Catalytic System

“…The activation of catalyst placed inside of a BaTiO 3 packed-bed plasma reactor was also observed in [11,12]. It was reported that plasma could initiate the benzene decomposition on photocatalyst (TiO 2 , Ag/TiO 2 and Pt/TiO 2 ) at as low temperature as 100°C.…”

“…Hence, in order to improve and increase the efficiency of VOC decomposition, an innovative technology has been proposed where a V. Demidyuk AE J. C. Whitehead (&) School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, UK e-mail: christopher.whitehead@manchester.ac.uk plasma reactor was coupled with a catalytic reactor [8][9][10][11][12][13]. Such a combination helps overcome some of the disadvantages of both catalytic and plasma treatments.…”

Comparative Actions of NiO and TiO2 Catalysts on the Destruction of Phenol and its Derivatives in a Dielectric Barrier Discharge

“…There are several discharge types and discharge setups for close contact obtained between plasma and a solution. These include glow discharges with one or two liquid electrodes [1][2][3], pulse positive streamer corona discharges generated in aqueous solutions [4][5][6] and dielectric barrier discharges (DBD) [7]. The application of a catalyst is another way of enhancing the process.…”

“…Therefore, the application of heterogeneous catalysts is more preferable. It was previously reported [7] that catalysts based on CuO and NiO increased the decomposition efficiency of phenol, resorcin and pyrocatechol in aqueous solutions through the action of an atmospheric pressure DBD in oxygen.…”

“…It is well-known that TiO 2 UV excitation leads to the formation of positive holes, which possess strong oxidizing activity [9]. In addition, the results were compared with those obtained with a NiO catalyst under the same experimental conditions [7]. The process of hydroquinone decomposition was also studied.…”