Hydrotalcite-like Purifier On NOx Removal Mechanism And Preparation

Diesel engine is used more and more widely on many kinds of autos and dynamicalequipments for its high dynamical and economical performances.But nitric oxide(NOx) isdiesel chief emissions, which is one of major pollutants in the atmosphere and causes greatharm to natural environment and human life. Greatly reduce NOx emissions need to bebetter closed to removal technology, the purpose of this paper is to search for moreeffective catalysts and their preparation, purifier for diesel engine NOx emissions docontribution to the development of new technology.In this paper, the reaction mechanism of removing NOx hydrotalcite compound hascarried on the preliminary discussion. The catalyst precursors containing Mg,Al,Ni,Cu andFe were prepared through coprecipition.X-ray diffraction analysis, infrared spectroscopy,thermal gravimetric analysis, scanning electron microscopy and BET characterizationanalysis were used for the characterization of the above prepared catalysts. Hydrotalcitewas calcined under a certain temperature, and composited metal oxide catalyst, accordingto the specific process conditions coated on ceramic honeycomb carrier, made into thehydrotalcite purifier.Through the establishment of simulation of diesel engine exhaustemission experiment device of the compound metal oxide catalyst powder and hydrotalcitepurifier performance of removing NO respectively, and different calcination temperature,reaction temperature, coating times and the existence of oxygen or not affect theperformance of the catalyst for removal.Experimental results show that under the condition of experiment, removal rate ofpurifier is higher than powder catalyst; Under optimized conditions (simulated flue gasflow rate of1L/min, NO concentration of600ppm, oxygen concentration of10%,temperature of250℃), the NO removal efficiency of MgAlNi hydrotalcite purifier is ashigh as76.9%.