[Reaction of NO with metal oxides and urea supported on activated carbons at low temperature].
The catalysts were prepared by activated carbon fiber (ACF) loaded different contents of NiO and NiO-CeO2, Urea was loaded on the prepared catalysts as reductant. The experiments of selective catalytic reductions (SCR) of NO were carried out from 30 to 120 degrees C. The experiments of SEM, BET and XRD of the samples were also carried out selectively to study the catalysts properties, respectively. The experimental results showed that the loaded mass fraction of NiO could greatly affect the catalytic activity of the catalysts. 10% NiO catalyst activity and activity stability were both higher than that of the others, and it could yield about 50% removal efficiency of NO at 90 degrees C. With the loaded mass increasing, the catalytic activity was obviously decreased. And furthermore, the catalyst of 5% NiO-5% CeO2/ACF had the best catalytic activities on SCR NO and stability among the prepared NiO-CeO2/ACF catalysts, and its NO removal efficiency was over 55% at 110 degrees C. When the loaded mass increased, the similar phenomenon was observed, which was due to the decreasing of specific surface area of the catalysts. The metal oxides, loaded on ACF, were the catalytic centers in this study. Moreover, 5% CeO2-5% NiO/ACF had the highest catalytic activity than 10% CeO2/ACF and 10% NiO/ ACF. Therefore, there should be synergistic effect between CeO2 and NiO. Finally, the catalytic mechanism of SCR on NO at low temperature was discussed.
(Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, College of Environmental Science and Engineering, Hunan University, Changsha 410082, China. chflihai@163.com
Hua-Fei
HF
Cui
Cai-Ting
CT
Li
Pei
P
Lu
Dun-Liang
DL
Peng
Jing
J
Guo
Ling
L
Chen
D000393:Air Pollutants / Q000032:analysis / Q000302:isolation & purification*; D002384:Catalysis; D002563:Cerium / Q000737:chemistry*; D002606:Charcoal / Q000737:chemistry*; D003080:Cold Temperature; D009532:Nickel / Q000737:chemistry; D009569:Nitric Oxide / Q000032:analysis / Q000302:isolation & purification*; D014508:Urea / Q000737:chemistry*
D000393:Air Pollutants; D002606:Charcoal; D002563:Cerium; D009569:Nitric Oxide; C030583:ceric oxide; D009532:Nickel; D014508:Urea; C028007:nickel monoxide