【摘要】 氮氧化物（NO_x）作为主要的大气污染物之一,在大气中容易经过一系列化学反应产生光化学烟雾或其他二次污染物,对生态环境和人类健康构成严重威胁。目前,我国空气污染问题依然严重,其中NO_x污染问题未得到有效控制。氨选择性催化还原技术（NH₃-SCR）是目前固定源烟气净化领域应用广泛且高效的烟气脱硝技术之一。目前商用V₂O₅-WO₃/TiO₂具有温窗较高、VO_x具有生物毒性及高温选择性差等缺点。从节能、环保和锅炉匹配等角度看,低温化是SCR技术的发展方向,因此已经引起了国内外众多科技工作者的极大关注。我国作为农业大国,农业废弃物总量大,而农业废弃物可通过多种手段制备出生物炭,因而生物炭具有来源广泛、成本低、环境友好等特点,且生物炭适合开发成催化剂应用于低温NH₃-SCR反应。综述了不同生物质源的炭基纳米材料在低温SCR技术中的应用,重点阐述了生物炭的制备工艺、改性等对炭基催化剂脱硝性能的影响;还对生物炭基催化剂的低温NH₃-SCR性能、抗硫抗水性能以及反应机理等方面进行了总结。最后,针对生物炭应用于低温NH₃-SCR脱硝催化剂所存在的问题,提出了改进意见,并对炭基低温SCR脱硝催化剂今后发展方向和应用前景进行了展望。更多还原

【Abstract】 Nitrogen Oxides（NO_x）,as one of the main air contaminant,incline to produce photochemical smog and other secondary pollutants by a series of chemical reactions in atmosphere and pose a serious threat to human health and the ecological environment.Currently,the air pollution in China is getting more severe,and the NO_x emissions have not been effectively controlled yet.Selective catalytic reduction（SCR）of NO_xwith NH₃ is an efficient and a widely used technology for flue gas denitrification（de NO_x）from stationary pollutant sources.At present,commercial catalyst（V₂O₅-WO₃/TiO₂）has several shortcomings including a narrow temperature operating window,biotoxicity for VO_x,and the low N₂ selectivity under high temperature condition,etc.From the perspective of energy saving,environmental protection,and boiler type matching etc.,low temperature technology is the main direction for the future development of SCR technology,so it has received much attention at home and abroad by researchers.China is a large agricultural country with a huge amount of agricultural wastes.And agriculture wastes can be treated and turned into biochar by a lot of means.Therefore,biochar has several characteristics,e.g.wide resources,low cost and environmental friendliness etc.,which is suitable for development as a catalyst application low temperature NH₃-SCR reaction.In this paper,the application of carbon-based nanomaterials derived from different biomass sources for low-temperature SCR is reviewed,and the effects of preparation process and modification of biochar on the SCR performance of carbonbased catalysts are emphasized.The low temperature NH₃-SCR performance,sulfur and water resistance and reaction mechanism of biochar-based catalysts are also summarized.Finally,the improvement suggestions are put forward for the problems existing in the application of biochar for low-temperature NH₃-SCR,and the future development direction and application prospect of carbon-based low-temperature SCR de NO_x catalysts are prospected.更多还原