Research Of Manganese-based Denitration Catalysts

With Chinese industry growing fastly these years, the environment pollution hasbeen a social problem. The removing of NOxhave been one of the targets of the12thFive-Year Plan.Too much NOxin the air can cause the hazy weather and acid rain. SelectiveCatalytic Reduction (SCR) is one of the main technical means to remove nitric oxides,and the catalyst researching is the key. As an increasing number of researchersstudying the denitration catalysts, the catalysts with different functions are developed.Recently, low temperature SCR technology has been eye-catching for its energyconservation and potential application. In this paper experiments were carried out toexplore the catalyst performance based on Mn.In this article, a series of experiments were conducted to research denitrationcatalyst based on Mn, including the catalyst carrier, manganese oxide, preparationcondition. The catalysts were characterized with XRD, XRF, NH3-TPD, BET andFT-IR, and the denitrification activity catalyst was evaluated in fixed bed reactor.In the experiment, Al2O3and TiO2were chosen as carriers, the catalysts wereprepared by impregnation method, by characterizing the surface crystal form andNH3-TPD, the differents between two kinds of carriers influence the denitrificationrate.The effects of preparation conditions were also researched, in the experiment,crystal form was depend on calcination temperature, and the capacity of Mn wascontrolled, the denification rate show that catalyst calcined at450℃, Mn loaded at4.4%perform better than other series.Preparation of manganese precursor have a direct impact to the oxidation state ofmanganese oxides, in this experiment, Mn(NO3)2, Mn(CH3COO)2and MnCO3wereused as precursors, Al2O3was the carrier, the denitrification activity of catalyst wasevaluted. The results of tests show that various valence of manganese mixed oxidecan promote the process of selective catalytic reduction, catalyst which containsdifferent manganese oxides has better performance of denitrification.