Preparation Of V₂O₅/TiO₂Catalysts Supported Onto Stainless Steel Plate And Their Selective Catalytic Reduction（SCR） Of NO_x

Nowadays, the selective catalytic reduction (SCR) of NOX by ammonia was the most efficient and widely technology for abating NOX emitted form stationary power stations. SCR reaction do not bring about secondary pollution, and it’s De-NOx efficiency is high. Therefore, the study on SCR catalysts to the firing flue gas in our country is important and meaningful. Based on De-NOx catalyst traditional designed has ideal denitrification efficiency but poor mechanical strength. In the thesis, De-NOx catalysts supported onto stainless steel plate that features low cost, simple production process, ideal catalytic activity and high mechanical strength were prepared.1. Firstly, TiO2carriers of different sources, different V2O5content, different promotor were investigated systematically. The performances of catalysts were characterized by BET, XRD and FT-IR methods. By thorough investigation, it was found that the catalyst was prepared by using sol-gel method which De-NOx efficiency was better than others to synthesize the carrier. NO conversion of this catalyst could reach to95%under space velocity of20000h-1. Then the selection and optimization of the ingredient, the operation parameters were developed. It was found that1.5%V2O5-6%WO3/TiO2catalyst powder based on anatase TiO2form sol-gel exhibited ideal catalysis activity. With investigating the denitrification activity on a fixed bed reactor, it was found that the initial concentration of NO was nothing to do with De-NOx efficiency. With the optimum O2content was6%, NO conversion of this catalyst could reach to90%under n(NH3)/n(NO) being1.2. Preparation methods and catalytic activity in SCR were studied. V2O5and WO3were impregnated sequentially onto TiO2for coating active component and co-catalyst.The V2O5/WO3/TiO2catalysts after sieving were mixed with organic and inorganic adhesives for obtaining the catalysts slurry. Postharvest sulfuric acid treatment the metallic plate was impregnated into sol prepared by Ti(OBu)4. It was emphasized that the catalyst performance was influenced by different adhesives, catalytic active component loaded on stainless steel plate.The performances of catalysts were characterized by BET, XRD, SEM and F-TIR methods. It was found that plate type catalyst which loading0.014g/cm2on the catalytic performance had as much reactivity as powdered ones, using PVA-colloidal SiO2as adhesives. Through check experiment, the influences of temperature, space velocity and SO2are also studied. The study showed that catalyst exhibited high catalytic activity, with NO conversion of92%under temperature ranging form350℃to360℃and space velocity of8000L/kgxh×h-1.3. Furthermore, tentative exploration of reparation of film-type catalyst and catalytic activity in SCR reaction were also carried out. As precursors, Vanadium(Ⅳ) oxide bis(2,4-pentanedionate) and Ti(OBu)4sol was prepared. Series of V2O5/TiO2thin films have been synthesized deposited on stainless steel plate substrate using sol-gel and dip-coating method. Effect of best ratio of Vanadium(IV) oxide bis(2,4-pentanedionate)/Ti(OBu)4and times of dip-coating were investigated. When the mass ratio of Vanadium(IV) oxide bis(2,4-pentanedionate)/Ti(OBu)4=0.7:63and times of dip-coating=5, the study showed that catalyst exhibited good stability, with NO conversion of80%at350℃under space velocity of10000L/kgxh×h-1.