Porous electrodes for hydrogen peroxide preparation by oxygen reduction. The influence of temperature and pressure applied in preparation of the electrodes on their functional properties

1981 ◽  
Vol 46 (9) ◽  
pp. 2052-2059 ◽  
Author(s):  
Otomar Špalek ◽  
Jan Balej
Keyword(s):  
Hydrogen Peroxide ◽  
Carbon Black ◽  
Current Density ◽  
Porous Electrodes ◽  
Current Yield ◽  
Electric Resistance ◽  
Influence Of Temperature ◽  
Electrode Mass ◽  
Temperature And Pressure ◽  
Wetted Surface Area

The influence of the temperature and pressure applied in preparation of porous electrodes from Teflon-bonded carbon black on the hydrogen peroxide current yield and the current density was investigated. The porous structure, the wetted surface area of carbon black, and the electric resistance of the electrode mass were examined in order to establish the factors responsible for the varying electrode activity.

Porous electrodes for the preparation of peroxide by reduction of oxygen; Influence of the content of polyethylene

1979 ◽  
Vol 44 (4) ◽  
pp. 996-1002 ◽  
Author(s):  
Otomar Špalek
Keyword(s):  
Carbon Black ◽  
Current Density ◽  
Porous Electrodes ◽  
Current Yield ◽  
Electric Resistance ◽  
Polyethylene Powder

With porous electrodes prepared by pressing a mixture of carbon black and polyethylene powder, the influence of the content of the binder on their electric resistance, wettability, current density, and current yield of peroxide during reduction of oxygen was studied.

Generation of hydrogen peroxide by reduction of oxygen in semihydrophobic trickle electrodes

1991 ◽  
Vol 56 (2) ◽  
pp. 309-316 ◽  
Author(s):  
Otomar Špalek ◽  
Karel Balogh
Keyword(s):  
Hydrogen Peroxide ◽  
Carbon Black ◽  
Oxygen Reduction ◽  
Surface Area ◽  
Phase Interface ◽  
Electrochemical Activity ◽  
Polarization Curves ◽  
Electric Resistance ◽  
Graphite Felt ◽  
Three Phase

The reduction of oxygen to hydrogen peroxide was studied in semihydrophobic trickle electrodes prepared from crushed graphite and teflonized carbon black. The potential of these electrodes was found markedly more positive and the peroxide current yields appreciably higher than for electrodes made of used crushed graphite. The reason for this is the higher surface area of the electrodes containing carbon black and occurrence of a three-phase interface in them. The relevant properties, i.e. electric resistance, electrolyte holdup, polarization curves for the oxygen reduction and pexide current yields, were also studied for trickle electrodes containing graphite felt. The electrochemical activity of electrodes made from untreated felt was found rather low but it increased several times when felt pretreated by oxidation was used.

Relation between the activity of electrodes from various carbonaceous meterials for reduction of oxygen to hydrogen peroxide and concentration of their paramagnetic centers

1980 ◽  
Vol 45 (12) ◽  
pp. 3249-3253 ◽  
Author(s):  
Jan Balej ◽  
Karel Balogh ◽  
Pavel Stopka ◽  
Otomar Špalek
Keyword(s):  
Hydrogen Peroxide ◽  
Alkali Metal ◽  
Porous Electrodes ◽  
Substantial Decrease ◽  
Current Yield ◽  
Paramagnetic Centers ◽  
Carbonaceous Materials

The current yield of hydrogen peroxide during cathodic readuction of oxygen in porous electrodes from various carbonaceous materials is the lower the higher is the number of paramagnetic centers in these materials. A substantial decrease in the concentration of paramagnetic centers by heating to 900 °C in vacuum is only temporary, whereas by heating with alkali metal sulphides it is practically permanent.

Calculation of potential and concentration gradients in trickle-bed electrodes producing hydrogen peroxide

1986 ◽  
Vol 51 (9) ◽  
pp. 1883-1898 ◽  
Author(s):  
Otomar Špalek
Keyword(s):  
Mathematical Model ◽  
Hydrogen Peroxide ◽  
Current Density ◽  
Potential Distribution ◽  
Current Flow ◽  
Anode Chamber ◽  
Current Yield ◽  
Concentration Gradients ◽  
Electrolyte Flow ◽  
Trickle Bed

A mathematical model for describing the trickle-bed electrode has been developed and used to calculate the potential distribution along the current flow and the hydrogen peroxide concentration profile along the electrolyte flow (normal to the direction of current). Polarization curves and dependences of the current yield of hydrogen peroxide and the peroxide losses due to the processes occurring (reduction, decomposition, and transport into the anode chamber) on the current density have also been calculated. A comparison is made between calculated and measured dependences of the current yield of hydrogen peroxide on the current density.

The influence of oxidized technical carbon N121 on the properties of butyl-based rubbers

2019 ◽  
pp. 123-128
Author(s):  
M. N. Nagornaya ◽  
A. V. Myshliavtsev ◽  
S. Ya. Khodakova
Keyword(s):  
Hydrogen Peroxide ◽  
Carbon Black ◽  
Gas Permeability ◽  
Mechanical Tests ◽  
Butyl Rubber ◽  
Rubber Mixture ◽  
Active Forms Of Oxygen ◽  
Technical Carbon ◽  
Furnace Black ◽  
The Subject

The subject of the study were samples of channel technical carbon K354, furnace technical carbon N121 and experimental – based on TUN121, oxidized with active forms of oxygen. Samples of carbon black were studied in the composition of a rubber mixture based on BK 1675N butyl rubber. The purpose of this study was to determine the possibility of using oxidized technical carbon N121 in fillers of rubber based on butyl rubber, instead of carbon black K354. The physicochemical properties of the samples of technical carbon under study, the results of physical and mechanical tests, and the gas permeability tests of rubber mixtures filled with the samples under study are presented. A conclusion is made about the possibility of replacing channel technical carbon K354 with furnace black carbon N121 oxidized with 30% hydrogen peroxide.

Palladium-catalyzed carbonylation of 1,5-cyclooctadiene. Effects of temperature and pressure

1991 ◽  
Vol 56 (3) ◽  
pp. 663-672 ◽  
Author(s):  
Curtis B. Anderson ◽  
Rade Marković
Keyword(s):  
Carbon Monoxide ◽  
Oxidative Carbonylation ◽  
Influence Of Temperature ◽  
Carbonylation Reaction ◽  
Palladium Catalyzed ◽  
Effects Of Temperature ◽  
Temperature And Pressure

The influence of temperature and carbon monoxide pressure on the course of oxidative carbonylation reaction of 1,5-cyclooctadiene in the presence of the palladium(II) salts as a catalyst, was investigated.

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