For the first time, a method was developed for introducing indium into Mg-Al hydrotalcites—precursors of oxide catalysts for oxidative dehydrogenation of alkanes. Samples of oxide catalysts were synthesized that contained indium oxide and also oxides of magnesium, aluminum, chromium, vanadium, molybdenum, and niobium in various combinations. The catalytic properties of the produced catalysts were studied in the oxidative dehydrogenation of ethane, propane, and isobutane. It was established that the introduction of indium into catalysts increases the selectivity and the yields of desired products. New hydroxo salts with a layered structure of the hydrotalcite type were synthesized: [Al1 − n In n Mg m (OH)3 + 2m − 1][(NO3) · nH2O] and quaternary magnesium indium chromium aluminum hydroxonitrate of the composition [Al0.5In0.5Cr0.5Mg2.5(OH)8.5][(NO3) · nH2O]; these salts were found to be isostructural. The obtained compounds were studied as catalyst precursors.
Solubility in the NaNO3 -NH4 NO3 -KNO3 -H2 O system
Solubility in the NaNO3-NH4NO3-KNO3-H2O four-component water-salt system was studied for the first time at 25, 40 and 60°C. The crystallization boundaries were determined for individual constituent salts, the double salt 3KNO3 · NH4NO3, potassium nitrate-based solid solutions, and ammonium nitrate-based solid solutions. The reported experimental data have been used to optimize a circular isohydric process for preparing potassium nitrate involving additional salts.