Activation of Cu-, Ag-, Au/ZrO2 Catalysts for Dehydrogenation of Alcohols by Low-Temperature Oxygen and Hydrogen Plasma

Пылинина, А. И.; Михаленко, И. И.

doi:10.1007/s11237-013-9296-8

Cited by 20 publications

(5 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result, the plasma and catalyst influence each other during operation. On one hand, the reactive plasma species (i.e., ions, radicals, and excited species) affect the catalyst properties, such as its morphology or its work function [15]- [16]. On the other hand, the existence of the packing beads (catalyst) in the reactor changes the electric field distribution and hence the discharge behaviour [17]- [18], which leads to changes in the plasma chemistry and in the plasma performance for environmental applications.…”

Section: Introductionmentioning

confidence: 99%

Streamer propagation in a packed bed plasma reactor for plasma catalysis applications

Wang

Kim

Laer

et al. 2018

Chemical Engineering Journal

167

157

View full text Add to dashboard Cite

A packed bed dielectric barrier discharge (DBD) is widely used for plasma catalysis applications, but the exact plasma characteristics in between the packing beads are far from understood. Therefore, we study here these plasma characteristics by means of fluid modelling and experimental observations using ICCD imaging, for packing materials with different dielectric constants. Our study reveals that a packed bed DBD reactor in dry air at atmospheric pressure may show three types of discharges, i.e. positive restrikes, filamentary microdischarges, which can also be localized between two packing beads, and surface discharges (so-called surface ionization waves). Restrikes between the dielectric surfaces result in the formation of filamentary microdischarges, while surface charging creates electric field components parallel to the dielectric surfaces, leading to the formation of surface discharges. A transition in discharge mode occurs from surface discharges to local filamentary discharges between the packing beads when the dielectric constant of the packing rises from 5 to 1000. This may have implications for the efficiency of plasma catalytic gas treatment, because the catalyst activation may be limited by constraining the discharge to the contact points of the beads. The production of reactive species occurs most in the positive restrikes, the surface discharges and the local microdischarges in between the beads, and is less significant in the longer filamentary microdischarges. The faster streamer propagation and discharge development with higher dielectric constant of the packing beads leads to a faster production of reactive species. This study is of great interest for plasma catalysis, where packing beads with different dielectric constants are often used as supports for the catalytic materials. It allows us to better understand how different packing materials can influence the performance of packed bed plasma reactors for environmental applications.

show abstract

Section: Introductionmentioning

confidence: 99%

Streamer propagation in a packed bed plasma reactor for plasma catalysis applications

Wang

Kim

Laer

et al. 2018

Chemical Engineering Journal

167

157

View full text Add to dashboard Cite

show abstract

“…In single-stage plasma catalysis systems, the interaction between the plasma and the catalyst is rather complicated, and this directly influences the performance of plasma catalysis. For instance, the reactants generated in the plasma phase arrive at the catalyst surface, affecting the electronic and chemical properties of the catalyst, i.e., the adsorption probability, oxidation state, as well as the work function [7][8][9][10][11][12]. In addition, the presence of a catalyst in the plasma zone may enhance the electric field, change the discharge type, and thus in turn affect the physical and chemical properties of the plasma [13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

“…Plasma catalysis has increasingly gained attention in recent years, for various environmental applications, such as gaseous pollutant removal, hydrocarbon reforming, and the conversion of greenhouse gases into value-added chemicals. − In single-stage plasma catalysis systems, the interaction between the plasma and the catalyst is rather complicated, and this directly influences the performance of plasma catalysis. For instance, the reactants generated in the plasma phase arrive at the catalyst surface, affecting the electronic and chemical properties of the catalyst, i.e., the adsorption probability, the oxidation state, and the work function. − In addition, the presence of a catalyst in the plasma zone may enhance the electric field, change the discharge type, and thus in turn affect the physical and chemical properties of the plasma. − …”

Section: Introductionmentioning

confidence: 99%

Influence of the Material Dielectric Constant on Plasma Generation inside Catalyst Pores

2016

View full text Add to dashboard Cite

Plasma catalysis is gaining increasing interest for various environmental applications, but the crucial question is whether plasma can be created inside catalyst pores and under which conditions. In practice, various catalytic support materials are used, with various dielectric constants. We investigate here the influence of the dielectric constant on the plasma properties inside catalyst pores and in the sheath in front of the pores, for various pore sizes. The calculations are performed by a two-dimensional fluid model for an atmospheric pressure dielectric barrier discharge in helium. The electron impact ionization rate, electron temperature, electron and ion density, as well as the potential distribution and surface charge density, are analyzed for a better understanding of the discharge behavior inside catalyst pores.The results indicate that in a 100 m pore, the electron impact ionization in the pore, which is characteristic for the plasma generation inside the pore, is greatly enhanced for dielectric constants below 300. Smaller pore sizes only yield enhanced ionization for smaller dielectric constants, i.e., up to  r = 200, 150 and 50 for pore sizes of 50 m, 30 m and 10 m. Thus, the

show abstract

“…Both plasma and catalysis interact with each other in PBR, with plasma affecting the physicochemical properties of the catalyst [6,7] and catalyst influencing plasma discharge modes and parameters [8][9][10]. Several studies have investigated the dynamic discharge evolution in PBR [11][12][13][14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Experimental and numerical investigation of surface streamers in a nanosecond pulsed packed bed reactor

Chen

Zhu

et al. 2023

Plasma Sources Sci. Technol.

View full text Add to dashboard Cite

Packed bed reactor (PBR) isthe commonly used configuration in Plasma-catalysis and the plasma characteristics has been extensively investigated. The filled catalysts in PBR makes it challenging to carry out in-situ measurement of electric field, and few experimental data has been obtained. We investigated the surface streamer propagation and electric field distribution in a simplified PBR through simulations and experiments. The simplified PBR in the experiments is comprised of a blade-plate electrode filled with a Al2O3 column (εr=9) in the discharge gap. An ICCD camera and an electric field diagnosis method called EFISH (Electric field induced second harmonic generation)were employed, while a two-dimensional fluid model was established for the simulation.Four discharge types in the PBR were identified based on ICCD images and simulation results, including polar discharge at the contact areas, surface streamer along the dielectric column, expansion of surface discharge along the dielectric column, and surface ionization waves along the dielectric plate. Surface streamers with opposite propagation directions were found, namely forward streamer during the pulse rising time and reverse streamer during the pulse falling time. Notably, the reverse streamer exhibits a significantly lower velocity compared to the forward streamer.Both experimental measurements and simulation were conducted to investigate the spatiotemporal electric field near the surface of the packing material. The results of both Eexp and Esim showed peaks with opposite polarities, and exhibited similar trends. In the simulation, the forward streamer head had a higher electric field compared to the reverse streamer head. Moreover, during the rest pulse time, the surface electric field was more intense at the contact areas than in other regions. The findings of this work provide valuable insights into the discharge mechanism and electric field on the catalytic material surface within the PBR.

show abstract

Activation of Cu-, Ag-, Au/ZrO2 Catalysts for Dehydrogenation of Alcohols by Low-Temperature Oxygen and Hydrogen Plasma

Cited by 20 publications

References 1 publication

Streamer propagation in a packed bed plasma reactor for plasma catalysis applications

Streamer propagation in a packed bed plasma reactor for plasma catalysis applications

Influence of the Material Dielectric Constant on Plasma Generation inside Catalyst Pores

Experimental and numerical investigation of surface streamers in a nanosecond pulsed packed bed reactor

Contact Info

Product

Resources

About