采用浸渍法用ZrOCl2·8H2O,Mn(NO3)2·6H2O和Fe(NO3)3·9H2O制备了Zr-Mn-Fe/Al2O3复合催化剂.通过调节质量分数分别为2%,5%和10%金属元素锰和锆的负载量制备了不同的催化剂,测试了其在NH3条件下的低温脱硝活性,研究了不同组分配比和氧气含量对催化剂脱硝性能的影响.通过在载体上分别单独负载Mn,Fe和Zr来探究脱硝过程中起主要作用的催化活性组分.实验结果表明,在体积分数φ(NO)=0.05%,摩尔比n(NH3)∶n(NO)=1∶1和φ(O2)=3.6%的条件下,制备的催化剂5Zr-5Mn-10Fe/Al2O3表现出很高的催化活性,在180℃时脱除效率超过了98%,是一种良好的低温SCR催化剂.Mn在脱硝过程中是主要的活性组分,而Zr和Fe是助催化组分.此外,在反应过程中通入一定的氧气,可以明显提高NO的脱除效率,能促进NO的转化.
Zr-Mn-Fe/Al2O3 catalysts were prepared by a simple impregnation method using ZrOCl2·8H2O,Mn(NO3)2·6H2O and Fe(NO3)3·9H2O on the Al2O3 carrier.The weight fractions of loading Mn and Zr on the catalysts were individually adjusted with 2%,5%,and 10%.These catalysts were used to investigate low temperature selective catalytic reduction of NO with ammonia.The influences of metal loading and O2on the de-NOx efficiency were also studied.Mn,Fe and Zr were individually loaded on Al2O3to ascertain the main catalytic activity component.Results show that the catalyst of 5Zr-5Mn-10Fe/Al2O3 is of higher de-NOx efficiency in the simulated flue gas of 0.05% NO with a 1∶1 NH3/NO molar ratio in the presence of a volume fraction of 3.6% O2.This catalyst yields 98% NO conversion at 180℃ under the mentioned conditions and is a type of good low temperature selective catalytic reduction(SCR) catalyst.Mn is the main acting component in the process of NO removal in this catalyst,while the Zr and Fe are acting as a promoter.In addition,oxygen can significantly improve the efficiency of NO removal.