Si2 N2 O was prepared by carbothermal reduction and nitridation of SiO2 at 1 500益. The catalytic
effect and mechanism of Fe2O3 on synthesis of Si2N2O were investigated by XRD and thermogravimetry. Fe2O3 had a
remarkable catalytic effect on synthesis of Si2N2O. A 100% conversion ratio of SiO2 could be achieved when adding a
little Fe2O3. The catalytic mechanism of Fe2O3 could be concluded as:on the one hand,the Fe2 O3 can be reduced to
nanosized Fe by C,which may form Fe-Si liquid with Si. The Fe-Si liquid can dissolve SiO2 and C particles and pro鄄
mote formation of the intermediate phase SiOC at a lower temperature,leading to a significantly decrease of the starting
temperature of carbothermal reduction. On the other hand,the CO2 can react with Fe-Si liquid to form SiO and CO,
which may enhance the reaction rate of carbothermal reduction.