Gas recombination

Electrochemical water splitting, generating H2 and O2 at separate electrodes, largely circumvents the gas recombination and high temperature limitations occurring in thermal hydrogen processes. Thus a hybrid of thermal dissociation and elec-... 

In the burnt gas recombination region of fast, fuel-rich hydrogen-nitrogen—oxygen flames the observed intensities of chemiluminescence for sodium and other metal additives were found [134] to obey the relation... 

Papers published over the past few years have described the benefits of gas recombination catalysts in VRLA cells [34-36]. The insertion of a catalyst into the headspace of a cell can assist the combination of a significant amount of hydrogen that would otherwise escape and constitute water loss. It is claimed that such catalysts not only reduce water loss but can also balance float charging of VRLA batteries. There remains some uncertainty, however, about the reliability and service-life of such catalysts. 

Besides a direct application of the hydrogen and oxygen electrodes in power sources (fuel cells, metal-air batteries, metal-hydrogen batteries, hydride cells) a application of gasconsuming electrodes consists in the gas-recombination in sealed cells. An application of the electro-catalysts for acidic electrolytes mentioned above could be the elimination of... 

In Region 1, many electrons and ions produced in the gas recombine because the voltage applied between cathode and anode is not large enough to collect all electrons. This region is not useful for counting radiation. 

The catalyst efficiency is measured by the ratio of the volume of restored (recombined) water in the plug vs. the volume of the decomposed water. Watanabe and Yonezu have determined the gas recombination efficiency of some catalyst materials as a function of the overcharge current [5]. Figure 14.2 shows the obtained results. 

As for any electrolyser, the membrane has to be mechanically stable to eventually support pressure. It has to be chemically stable regarding reducing and oxidising chemicals (O2 and H2) and gastight to avoid gas recombination. The membrane has to be a good protonic conductor and a poor electronic one. Moreover, it has to resist temperature (up to 100-120°C) and pressure (up to 30 bar or more). 

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