Hydrogen bombardment of amorphous hydrogenated silicon carbides is modeled with molecular dynamics simulations. At 30 eV, the minimum chemical sputtering yield of carbon is observed for the 10 at.% Si-doped structure, and is roughly by a factor of 1.5 lower than for pure carbon. In addition, silicon sputtering is negligible throughout the simulations. A clear hydrogen isotope dependency of the carbon sputtering yield is observed, similarly to the case of undoped carbon. The results indicate that silicon doping of carbon materials can improve the lifetime of plasma-facing materials and reduce the core plasma contamination in fusion devices.