Study On Preparation And Performance Of Low Temperature Manganese Base Denitration Catalyst

In order to reduce the emission of nitrogen oxides（NO_x）in flue gas,the catalyst emerged.Traditional vanadium-titanium catalysts are most widely used,but due to the high temperature and high dust working environment,it is easy to produce catalyst blockage,poisoning,reduced activity,short life and other problems.In order to improve the above phenomenon,the research focus is turned to low temperature Mn-based denitration catalyst.In this paper,the doping of Ce and La of low temperature manganese base denitration catalyst with TiO₂ as carrier was carried out,and characterized by particle size,XRD,SEM,FT-IR and other detection means.It was found that the doping of Ce and La could improve the catalytic activity and reduce the toxicity of SO₂ on the low-temperature Mn-based denitration catalyst by modifying the low-temperature Mn-based denitration catalyst.In addition,the sulfur resistance was improved by the effect of SO₄^2-acidification treatment on the sulfur resistance.Firstly,the optimal content of pure manganese oxide was determined.It was modified by doping Ce and La to determine the optimal doping amount.The optimal conditions were determined by exploring and controlling its carrier and preparation conditions.Finally,it was acidified to study its sulfur resistance.The results show that:（1）TiO₂ as the carrier,in the presence of 2mol/L NH₃·H₂O precipitator by the method of co-precipitation,p H=10 as the end point of precipitation;After precipitation,it was first aged for 24h.The oven was dried at 85℃for 10h.After grinding,it was roasted in muffle furnace at 500℃for 2h.（2）In the doping modification experiment,it was found that the optimal material ratio was 17%Mn and 1:6 La/Ce.After characterization,it can be seen that the specific surface of the low temperature Mn-based denitration catalyst prepared under these conditions is 188.19m²/g,and the catalytic efficiency is 87.1%in the temperature range of 80-220℃.（3）In the acidification experiment,under the optimal acidification condition of 0.2mol/L H₂SO₄,the specific surface area is 105.34 m²/g,the catalytic efficiency is 84%,which improves the sulfur resistance of the catalyst and prolongs the service life of the catalyst.TiO₂ is considered as an excellent carrier because of its abundant active sites and high specific surface area.Mn is a good component of low temperature catalyst.The doping of Ce and La can enhance the low temperature activity of low temperature catalyst,broaden the operating temperature range,protect the main active components,provide active sites,etc.,which are conducive to the improvement of low temperature catalytic activity.The synergistic reaction between the active components such as Mn,Ce,La and Ti can improve the activity of the low temperature catalyst.During acidification treatment,SO₄^2-combined with active components such as Ce and La to form metal sulfate,which greatly improved the sulfur resistance of low-temperature Mn-based denitration catalyst and contributed to the improvement of catalytic activity.The study of low temperature catalyst in this paper is of great significance to reduce the working temperature of catalyst,reduce the toxic effect of soot and SO₂ in flue gas on catalyst and extend the service life of catalyst.