Transport properties and modification of potassium dihydrogen orthophosphate

We have studied the thermal behavior, proton conductivity, and structural properties of composite proton electrolytes based on KH₂PO₄, the mixed salt K_0.97Cs_0.03(H₂PO₄)_0.97(HSO₄)_0.03, and silicon dioxide with a pore size of 70 Å in a wide composition range. The results demonstrate that the proton conductivity of the (1–x)KH₂PO_4–xSiO₂ (x = 0.1–0.5) composite systems increases by more than two orders of magnitude, reaching 3 × 10^–3 S/cm at a temperature of 225°C. The increase in conductivity is due to the formation of a disordered amorphous state of the salts as a result of partial KH₂PO₄ dehydration and the formation of K₄H₆(PO₄)₂P₂O₇ as an intermediate product. In the composites based on the highly conductive, disordered K_0.97Cs_0.03(H₂PO₄)_0.97(HSO₄)_0.03 mixed salt, close in composition to KH₂PO₄, heterogeneous doping causes no increase in conductivity, and the conductivity decreases with increasing doping level, which is caused by dispersion of the salt and the dehydration process, leading to the formation of K₄H₆(PO₄)₂P₂O₇ and KPO₃.     

Process of Extraction of Gallium from Technological Solutions with the Use of Ion Exchange Resins

Metallurgist - D-403 weakly basic anion exchange resin is used for the sorption extraction of gallium in the form of hydroxo complexes from alkaline aluminate solutions. The thermodynamic...     

Production of isobutylene from acetone over micro–mesoporous catalysts

The production of isobutylene from acetone over micro–mesoporous catalysts with different mesopore contents, which have been prepared using hydrothermal recrystallization of mordenite (MOR) zeolite modified with cesium acetate by incipient wetness impregnation, has been studied. It has been shown that cesium is inserted into the cation positions during the modification, at the same time the number of Brønsted acid sites in the samples decreased. It has been found that an increase in the content of mesopores in the catalyst leads to an increase in the initial rates of acetone conversion and isobutylene formation as a result of removing diffusion limitations. Brønsted acid sites have been shown to be preferable for the selective production of isobutylene from acetone. Micro–mesoporous materials operate more stably as compared to microporous materials.