SOLID-STATE REACTION IN MG-V-O-SB CATALYSTS

MgVO oxide with Mg/V atomic ratios of 2/2 and 3/2, were mixed mechanic ally with alpha-Sb2O4. Chemical changes during oxidative dehydrogenati on of propane (ODP) and under calcination treatment were studied. In M g/V(2/2) + alpha-Sb2O4, magnesium vanadate is contaminated during ODP and a new phase, MgSb2O6, was formed after only 1 day of calcination a t 823 K. In Mg/V(3/2) + alpha-Sb2O4, no indication of surface contamin ation or new phase formation was detected during ODP or calcination. T he catalytic performances of both mixtures are explained in the light of these results.