Performance MnO_x-CeO₂/ACFN Catalysts For Selective Catalytic Reduction Of No At Low Temperature

NO is one of the main atmospheric pollutants, which it not only bring harm to human health but also pollute ecological environment. With the rapid development of thermal power industry in China in recent years, the pollution caused by NO emissions has become more and more serious. At present, the work for reducing NO has been subsumed into "the twelfth five" planning about environmental protection, In order to complete the binding indicator reducing NO emission by10%, strengthening the scientific research about technology and principle of selective catalytic reduction (SCR) with ammonia, and developing denitration catalyst which possess excellent low temperature performance and proprietary intellectual property rights are becoming more and more urgent.MnOx/ACFN and CeO2/ACFN catalyst was prepared by using activated carbon fiber, modified by HNO3liquidus oxidation as catalyst support and choosing MnOx and CeO2as active component. The influences of calcination temperature and the loading of MnOx and CeO2for improving the NO conversion of on MnOx/ACFN and CeO2/ACFN catalyst were investigated by SCR of NO with NH3in the tubular reactor, combining with SEM and XRD test. The results showed that when the calcining temperature was500℃, the reaction temperature was200℃, the loadings of MnOx and CeO2were9%and7%, the maximum removals of NO by MnOx/ACFN and CeO2/ACFN catalyst were80.1%and81.2%, respectively.MnOx-CeO2/ACFN catalyst was prepared by co-precipitation and impregnation methods. The influences of the specification of ACFN, the molar ratios of Mn to Ce, preparation methods and the loading of active components were investigated, and the related catalysts were charactered with SEM, BET and XRD test. Taken ACFN1600as catalyst support at the molar ratio of Mn to Ce of2:3comparied with the conversion of NO under different loadings of catalysts by two different loading methods. The result showed that when on15%loading, the highest activity of the catalyst reached92.2%by co-precipitation method; on10%loading, the highest activity of the catalyst reached85.7%by impregnation method.The experiment was done in a tubular reactor and reaction temperature, oxygen content, gas hourly space velocity, concentration of NO and NH3all affect the SCR reaction. The results showed that catalyst15%MnOx-CeO2/ACFN(CP) exhibit a high activity at low temperature Conversion of NO reached92.2%under the conditions of reaction temperature200℃, gas hourly space velocity5000h-1, oxygen content5%and the concentration of NO and NH3was500ppm.