ABSTRACT Selective catalytic reduction of nitrogen oxides (SCR) with loaded urea is a method for removing NO under oxygen-rich and low-temperature conditions, which can solve the inhibitory effect of oxygen on the catalyst and the slip of ammonia. In present study, a series of activated carbon (wo-AC, co-AC, cs-AC and nu-AC) supported metal (Mn, Fe, Co, Cu and Zn) oxide catalysts with loading urea were prepared by ultrasonic assisted impregnation. The catalysts were used for NO removal at 50–120°C and characterized by XRD, SEM, GFAAS, EDS, XPS, BET and FTIR techniques. The effects of activated carbon type, loaded active element, metal oxides loading, temperature fluctuation on catalytic activity and the catalytic stability were also studied in this paper. The results indicated that nutshell-based activated carbon was more suitable as a carrier than other activated carbons, and urea-10Mn/nu-AC catalyst yielded a higher NO conversion than other catalysts. Besides, for used activated carbons, the larger specific surface area, more micropores distribution and the larger number of hydroxyl group and cyano terminal group are beneficial to the catalytic process. Moreover, the downward trend of NO conversion with increasing temperature suggested the adsorption of reactant gases played a crucial role in the catalytic process of urea-SCR. GRAPHICAL ABSTRACT

中文翻译：

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活性炭负载催化剂负载尿素用于低温脱除烟气中的 NO

摘要 负载尿素选择性催化还原氮氧化物 (SCR) 是一种在富氧低温条件下去除 NO 的方法，可以解决氧气对催化剂的抑制作用和氨的逃逸。在本研究中，通过超声辅助浸渍制备了一系列负载尿素的活性炭（wo-AC、co-AC、cs-AC 和 nu-AC）负载金属（Mn、Fe、Co、Cu 和 Zn）氧化物催化剂。 . 该催化剂用于在 50-120°C 下去除 NO，并通过 XRD、SEM、GFAAS、EDS、XPS、BET 和 FTIR 技术进行表征。本文还研究了活性炭类型、负载活性元素、金属氧化物负载量、温度波动对催化活性和催化稳定性的影响。结果表明，果壳型活性炭比其他活性炭更适合作为载体，尿素-10Mn/nu-AC催化剂比其他催化剂产生更高的NO转化率。此外，对于使用过的活性炭，更大的比表面积、更多的微孔分布以及更多的羟基和氰基端基有利于催化过程。此外，随着温度升高，NO转化率呈下降趋势，表明反应气体的吸附在尿素-SCR催化过程中起着至关重要的作用。图形概要 更多的微孔分布和更多的羟基和氰基端基有利于催化过程。此外，随着温度升高，NO转化率呈下降趋势，表明反应气体的吸附在尿素-SCR催化过程中起着至关重要的作用。图形概要 更多的微孔分布和更多的羟基和氰基端基有利于催化过程。此外，随着温度升高，NO转化率呈下降趋势，表明反应气体的吸附在尿素-SCR催化过程中起着至关重要的作用。图形概要