ZrO 2(Y 2O 3) powder and SiC nanopowder were prepared by carbothermal reduction of ZrSiO 4. With the existence of additive Y 2O 3 and other impurities, ZrSiO 4 was dissociated into ZrO 2 and SiO 2 in the condition of 1450—1550?℃. ZrO 2(Y 2O 3)powder was thus obtained via the removal of SiO 2 as silicon oxide (SiO) gas during carbothermal reduction process. SiC nanopowder and small amount of SiC whisker were synthesized form the gas-phase reaction between SiO vapor and supplied CH 4 gas.
The catalyst of nanometer Ag supported on nanomter TiO 2 particles was synthesized by irradiating TiO 2 colloid containing AgNO 3 solution.Its properties were characterized by IR,TEM,XRD,and BET methods.The size of catalyst particles was 12 1nm,composed by 95% TiO 2 and 5% Ag.The experimental results showed that the catalyst of nanometer Ag supported on nanometer TiO 2 improved obviously the activity and selectivity in the epoxidation of styrene.
