Catalytic performance of Ag/Al2O3-C2H5OH-Cu/Al2O3 system for the removal of NOx from diesel engine exhaust.
The selective catalytic reduction (SCR) of NOx by C(2)H(5)OH was studied in excess oxygen over Ag/Al(2)O(3) catalysts with different Ag loadings at lab conditions. The 4% Ag/Al(2)O(3) has the highest activity for the C(2)H(5)OH-SCR of NOx with a drawback of simultaneously producing CO and unburned THC in effluent gases. An oxidation catalyst 10% Cu/Al(2)O(3) was directly placed after the Ag/Al(2)O(3) to remove CO and unburned THC. Washcoated honeycomb catalysts were prepared based on the 4% Ag/Al(2)O(3) and 10% Cu/Al(2)O(3) powders and tested for the C(2)H(5)OH-SCR of NOx on a diesel engine at the practical operating conditions. Compared with the Ag/Al(2)O(3) powder, the Ag/Al(2)O(3) washcoated honeycomb catalyst (SCR catalyst) has a similar activity for NOx reduction by C(2)H(5)OH and the drawback of increasing the CO and unburned THC emissions. Using the SCR+Oxi composite catalyst with the optimization of C(2)H(5)OH addition, the diesel engine completely meets EURO III emission standards.
Zhang
Changbin
C
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
He
Hong
H
Shuai
Shijin
S
Wang
Jianxin
J
D000393:Air Pollutants / Q000737:chemistry* / Q000633:toxicity; D000397:Air Pollution / Q000517:prevention & control; D000537:Aluminum Oxide / Q000737:chemistry*; D002248:Carbon Monoxide / Q000737:chemistry; D002384:Catalysis; D000431:Ethanol / Q000737:chemistry*; D009589:Nitrogen Oxides / Q000737:chemistry* / Q000633:toxicity; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013696:Temperature; D001335:Vehicle Emissions / Q000633:toxicity*
D000393:Air Pollutants; D009589:Nitrogen Oxides; D001335:Vehicle Emissions; D000431:Ethanol; D012834:Silver; D002248:Carbon Monoxide; D000537:Aluminum Oxide; D010100:Oxygen