Zr-Mn-Fe/Al_2O_3的低温脱硝性能

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.

Performance of low temperature De-NO_x based on Zr-Mn-Fe/Al_2O_3

Zr-Mn-Fe/Al_2O_3 catalysts were prepared by a simple impregnation method using ZrOCl_2·8H_2O,Mn(NO_3)_2·6H_2O and Fe(NO_3)_3·9H_2O 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 O_2on the De-NO_x efficiency were also studied. Mn, Fe and Zr were individually loaded on Al_2O_3to ascertain the main catalytic activity component. Results show that the catalyst of 5Zr-5Mn-10Fe/Al2O3 is of higher De-NO_x efficiency in the simulated flue gas of 0.05% NO with a 1 ∶ 1 NH_3/NO molar ratio in the presence of a volume fraction of 3.6% O_2. 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.