Influence of calcination temperature of acidic ammonium salts of phosphotungstic acid on their composition and properties

The effect of the calcination temperature on the structure and properties of acidic ammonium salt (NH4)(2)HPW12O40 was studied. The absence of the influence of the calcination temperature of the samples on their particle size distribution, thermal stability and water content was shown. In the investigated range from 300 to 450 degrees C, a nonmonotonic change in the specific surface area and proton-conducting properties is observed depending on the calcination temperature. Calcination at a temperature other than optimal leads to a decrease in the specific surface area and proton conducting properties. A lower temperature is probably not enough for a complete redistribution of protons and ammonium ions; and an increase in the calcination temperature above optimal one entails the compaction of the salt crystallites.

Automated summary

The effect of calcination temperature on the structure and properties of acidic ammonium salt (NH4)(2)HPW12O40 was studied. It was found that the specific surface area and proton-conducting properties show a nonmonotonic change with different calcination temperatures. Choosing a temperature other than the optimal one for calcination leads to a decrease in the specific surface area and proton conducting properties.