Potassium hexatitanate

Typical components in a fiietion material are shown in Table 13.4. The formulations are eured at high pressure and temperatures. It has been found out that potassium hexatitanate and potassium octatitanate fibers should be used together. In this way, the performance of the mixture can be increased considerably. 

The electrolyte in the AFC is concentrated (85 wt%) KOH in cells designed for operation at high temperature ( 260°C) or less concentrated (35-50 wt%) KOH for lower temperature (<120°C) operation. AFC electrolyte development has been restricted to KOH water solutions with normalities ranging from 6 to 8. For immobilized cells, the electrolyte is retained in a matrix. Previously, asbestos was used as matrix material. However, because of its health hazards, material like potassium hexatitanate bonded with polytetra-fluoroethylene (PTFE) have been considered as matrix material. 

Cao et al. [163] for the first time introduced a continuous and intergrown Cu-BTC membrane prepared on novel potassium hexatitanate support through in situ growth. This kind of support can adsorb Cu in a moderate acid environment and is more suitable for the growth of Cu -containing MOF membranes than other traditional supports, such as porous alumina support. Compared to other MOF membranes, the Cu-BTC membrane showed a higher selectivity for He over CO2, Nj, and CH4. Thus, this kind of membrane may have potential applications for helium recovery. 

From XRD it is concluded that upon addition of potassium to both the Fe-Ti-O system and titania, in the fresh samples compounds containing the added potassium are formed. In the first case the resulting phase is probably the non-stoichiometric oxide K0JFe08TiIJO4 [13], whereas in the latter this is the hexatitanate KjTi6On. 

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