Nanoparticles have proven to be successful catalysts for oil combustion. To maximize their catalytic performance, it is necessary to provide nanoparticle aggregation stability during the combustion process. The classical approach to stabilization of nanoparticles assumes application of different stabilizers, like surfactants or polymers, attached to particles' surfaces, preventing their aggregation via steric or electrostatic repulsion. Thus, the aggregation stability of nanoparticles is determined by the thermal stability of the surfactant- or polymer-based coatings, which is not sufficient for high-temperature processes. In the current study we prepared a catalyst with high thermal stability by immobilization of 10 nm sized MnOx nanoparticles on a surface of 70 nm silica nanospheres. The composition, morphological, and textural parameters of the catalyst were optimized via variation of synthetic conditions. The high catalytic performance of the obtained nanoparticles in heavy oil combustion was proven by evaluation of kinetic parameters of catalytic and noncatalytic processes.