A carbon-nanotube-supported RuO2 nanocatalyst encapsulated in thin silica layer was successfully synthesized. The prior formation of silica over RuO2 nanoparticles effectively hindered catalyst aggregation at high temperatures. The significant improvement of the resistance to sintering and the catalytic selectivity were demonstrated in competitive oxidation of n-butanol and i-butanol and methanol oxidative dehydrogenation.