Preparation And Denitration Performance Study On Containing Cerium SCR Catalysts

Selective catalytic reduction?SCR?is one of the fuel gas denitration technology that is applied widely and has high denitration efficiency.In this paper,abundant and non-toxic harmless Ce/TiO₂ based components catalysts were researched..A kind of CeO₂/TiO₂ catalyst and several component proportion of CeO₂-Fe2O3/TiO₂ and Ce-Fe-Mn/TiO₂ catalysts were prepared by impregnation method.CeO₂-Fe2O3/TiO₂ was prepared by sol gel method.Through the denitration efficiency test of these samples,we can get the influence of different active components and different preparation methods on denitration catalyst performance.The results show that 10%-3% Ce-Fe/TiO₂?molar mass ratio?and 10%-3%-5% Ce-Fe-Mn/TiO₂ catalysts have the best denitration performance.10%-3% Ce-Fe/TiO₂ catalyst by impregnation method under the condition that temperature is 350 ? and the space velocity ratio is 10000 h-1,the denitration efficiency can reach 95.65%.Denitration efficiency is above 97% in 300⁴00 ? temperature range.10%-3%-5% Ce-Fe-Mn/TiO₂ catalyst by impregnation method in 150³00 ? tempreture range,it's denitration efficiency is more than 90%.The influence of oxygen concentration,initial concentration,space velocity ratio and NO ammonia nitrogen molar ratio on CeO₂-Fe2O3/TiO₂ and Ce-Fe-Mn/TiO₂ catalyst denitration efficiency were studied.The experimental results show that 3% and 2% or more oxygen concentration of simulated flue gas has less effect on the catalyst efficiency;Increase of NO initial concentration and space velocity value lead to its denitration efficiency decline;Ammonia nitrogen ration is less than 1,the catalysy had a greater influence on the denitration efficiency.Ammonia nitrogen ration is 1 or more has less effect on efficiency.The experiment on iron catalyst reaction kinetics is studied.The NH3,O₂ and NO transient response experiment study on Ce-Fe/TiO₂ shows that the catalyst is mainly follow Eley-Rideal reaction mechanism.Catalytic reaction rate equation with NO and O₂ reaction series were obtained.Influences of SO₂ and alkali metal on the denitration catalyst were studied.The results showed that SO₂ had a great influenct on 10% Ce/TiO₂ catalyst denitration efficiency.Catalyst with Fe oxides has better SO₂ resistance than that of Ce/TiO₂ catalyst.CeO₂-Fe2O3/TiO₂ and Ce-Fe-Mn/TiO₂ catalysts have good resistance to SO₂.The 10% addition of alkali metal reduce denitration efficiency of catalyst.K salt has more influencing than Na salt.