预处理对CNTs低温催化氧化NH3性能的影响

用浓酸混合液(浓H2SO4,H2O2)和非热等离子体(NTP)对碳纳米管(CNTs)进行预处理,对比2种方法预处理的CNTs在负载不同活性组分时NH3的催化氧化性能,实验结果表明,浓酸混合液预处理后的CNTs,负载不同单活性组份时,NH3转化率均低于50%,产物中没有NO和NO2。负载不同双活性组分时,5%Co-5%Zr/CNTs在200~225℃间,NH3的转化效率达到55%。NTP预处理的CNTs催化剂NH3的氧化性能高于浓酸混合液预处理的CNTs催化剂,在250℃时5%Cu/CNTs催化剂NH3的转化率基本接近90%。而250℃时,5%Cu-5%Zr/CNTs催化剂NH3转化率约为80%,NO的生成率约为75%,NO2生成率约3%。

Effects of pretreatment on low temperature selective catalytic oxidation of NH3 by CNTs

CNTs were pretreated with a concentrated acid mixture of H2SO4 and H2O2 or non-thermal plasma (NTP).Performance of the pretreated CNTs loaded with different active components in selective catalytic oxidation (SCO) of NH3 was investigated.The results showed that the NH3 conversion on the CNTs loaded with a single active component was lower than 50%, and no NO or NO2 was detected.However, the NH3 oxidative efficiency on 5%Co-5%Zr/CNTs was 55% in the temperature range from 200 to 225℃.The performance of CNTs pretreated with NTP was better than those pretreated with the concentrated acid mixture for SCO of NH3.The NH3 conversion on 5%Cu/CNTs was 90% at 250℃, while that over 5%Cu-5%Zr/CNTs was approximately 80%.The NO yield was approximately 75% and the NO2 yield was approximately 3%.