A series of vanadia catalysts supported on the mesoporous silica SBA-15 are synthesized using an automated laboratory reactor. The catalysts contain from 0.6 up to 13.6V atoms/nm and are structurally characterized by various techniques (BET, XRD, SEM, TEM, Raman, IR, UV/Vis). Samples containing up to 3.1V/nm are structurally rather similar. They all contain a mixture of tetrahedral (VOx)n speci...