Fabrication of MoO₃/TiO₂-SiO₂ with hollow spherical shape using resin as the template: Effect of decomposition of resins

Anion exchange resins are widely used in template synthesis of oxide composites. The present work is aimed to study the thermal destruction of anion exchangers with divinyl-benzene and polyacrylate matrices in order to obtain hollow spherical MoO₃/TiO₂–SiO₂ composites from these resins preliminarily saturated with paramolybate ion and coated with tetrabutoxytitanium sol with tetroethoxysilane. It is shown that the processes of resins decomposition affect the strength of spherical composites. Decomposition of the resin with a polyacrylate matrix, accompanied by random nucleation and burnout of the organic matrix at 350°C, leads to the formation of spherical oxide composites with cracks on the surface. The decomposition reactions of the resin with a divinylbenzene matrix occurring at the boundaries of the phases of cylindrical and spherical symmetry, as well as a lower burnout temperature of the organic matrix (290°C), contribute to the formation of dense MoO₃/TiO₂–SiO₂ spheres. Hollow spherical composites 0.3–0.5 mm in size are orthorhombic α-MoO₃ coated with a mixture of titanium dioxide with anatase structure and amorphous silicon dioxide.