Chromic Oxide Catalysts For Catalytic Oxidation Of NO At Room Temperatures

Common techniques of NO catalytic oxidation need a higher reaction temperatures（usually 200 400 oC） such as Relective Catalytic Reduction（SCR）,so it can not be applied to the Semi-closed space.Chromic oxide catalysts were studied for the oxidation and reduction of NO in in this paper at ambient temperature.Chromic oxide catalysts were prepared with a precipitation method for catalytic oxidation of NO at room temperatures. Effects of the precipitant, calcination temperature,concentration of NO and space velocity on NO conversion over the chromic oxide catalyst were investigated. Chromic oxide catalysts exhibited superior catalytic activity and long-time stability for NO oxidation compared with conventional activated carbon nanofibers and activated carbon. When the concentration of NO was 5 ppm and space velocity was 43200mL/h, NO removal rate 100 % can be kept above 500 minutes over the chromic oxide catalyst.The chromic oxide catalysts prepared using ammonia, NH4HCO3 and KOH as the precipitant and calcined at 300 oC showed considerably high NO removal rate and good long time running,while calcined at 400 oC showed the low stability for conversion of NO to NO2.TG, XRD, SEM, H₂-TPR, BET,Raman and XPS tests showed that amorphous chromic oxide catalysts with surface group meanwhile without potassium element exhibited the desired catalytic activity and long-time stability for NO oxidation.