Sol-gel synthesis and characterization of two-component systems based on MgO

A series of two-component MO (x) -MgO systems, where M is Cu, Ni, Co, Fe, Mo or W, was synthesized by sol-gel technique. Aqueous solution of inorganic salt-precursor was used as a hydrolyzing agent. Initial xerogels and final oxides were characterized using X-ray diffraction analysis, scanning electron microscopy and low-temperature nitrogen adsorption. Decomposition of xerogels was studied by differential thermal analysis. According to X-ray diffraction analysis, all xerogel samples are characterized with turbostratic structures regardless of nature of the second component. At the same time, presence of inorganic salt in magnesium hydroxide matrix shifts the temperature of decomposition of latter towards lower values. Structural and textural characteristics of MgO-based oxide systems were found to be strongly affected by the additive. Formation of joint phase was observed in the case of cobalt oxide. In most cases, additives turned out to be even distributed in the bulk of MgO, except for WO3. This oxide formed large agglomerates because of low solubility of precursor. [GRAPHICS] .