Ag-Nb-Pt Bazlı SCR Katalizör Karakterizasyonu

Öz

Seçici Katalitik İndirgeme (SCR), dizel motorlarda NOx emisyonlarını azaltmak için kullanılan bir emisyon kontrol sistemidir. Bu çalışmada, SCR sistemi için gümüş esaslı katalizörün sentezlenmesi deneysel olarak incelenmiştir. Bu amaçla, kordiyerit (2Al2O3-5SiO2-2MgO) yapısını daldırma yöntemiyle kaplamak amacıyla gümüş nitrat (AgNO3), niyobyum (V) klorür (NbCl5) ve tetra amin platin (II) nitrat (Pt (NH3)4 (NO3)2) katalizörleri kullanılmıştır. Katalizörün kimyasal ve fiziksel özelliklerini belirlemek için XRF, SEM ve BET analizleri gerçekleştirilmiştir. Sonuçlar, kaplama malzemelerinin gözeneklerin tüm yüzeyine nüfuz ettiğini göstermiştir. Üretilen katalizör ve kordieritin BET yüzey alanlarının sırasıyla 0,2918 m2/g ve 0,4568 m2/g olduğu belirlenmiştir. Yüzey alandaki azalmanın, yüksek sinterleme sıcaklığında meydana gelen kimyasal reaksiyonlarla kristalizasyon artışına bağlı olduğu düşünülmektedir. Ayrıca, XRF analizi sonuçları, kordierit yapısındaki Ag içeriğinin %0,03 olmasına karşın katalizörde Ag, Pt ve Nb içeriğinin sırasıyla %3,67, %0,19 ve %0,12 oranlarında olduğunu ortaya koymuştur. 

Anahtar Kelimeler

• Katalizör,XRF,SEM,BET,SCR,Egzoz emisyonları

Characterization of SCR Catalyst Based Ag-Nb-Pt

Öz

Selective Catalytic Reduction (SCR) is an emission control system used in diesel engines to reduce NOx emissions. In this study, synthesized of catalyst for SCR system was investigated as experimentally. For this purpose, silver nitrate (AgNO3), niobium (V) chloride (NbCl5) and tetra amine platinum (II) nitrate (Pt(NH3)4(NO3)2) were used to coat the cordierite (2Al2O3-5SiO2-2MgO) structure with impregnation method. X-ray Fluorescence (XRF), Scanning Electron Microscope (SEM) and Brunauer, Emmett, and Teller (BET) analyzes were carried out in order to determine the chemical and physical properties of the catalyst. Results showed that the coating materials penetrate the entire surface of the pores. It was also determined that the BET specific surface areas of the produced catalyst and cordierite are 0.2918 m2/g and 0.4568 m2/g, respectively. The reduction of surface area could be attributed to the increment of crystallization with chemical reactions occurred at the high sintering temperature. Besides, XRF analysis results demonstrated that content of Ag, Pt and Nb in the in the catalyst was found to be 3.67%, 0.19% and 0.12%, respectively, whereas Ag content in cordierite structure was 0.03%. 

Anahtar Kelimeler

• Catalyst,XRF,SEM,BET,SCR,Exhaust emissions

Kaynakça

1. 1. Resitoglu, I.A., Altınısık, K., Keskin A., 2015. The Pollutant Emissions from Diesel-engine Vehicles and Exhaust Aftertreatment Systems. Clean Tech. Environ. 17, 15-27.
2. 2. Bell, J.N.B., Honour, S.L., Power, S.A., 2011. Effects of Vehicle Exhaust Emissions on Urban Wild Plant Species. Environ. Pollut. 159, 1984-1990.
3. 3. Lee, T., Park, J., Kwon, S., Lee, J., Kim, J., 2013. Variability in Operation-based NOx Emission Factors with Different Test Routes, and its Effects on the Real-driving Emissions of Light Diesel Vehicles. Sci. Total Environ. 461-462, 377–385.
4. 4. Guan, W., Pedrozo, V., Zhao, H., Ban, Z., Lin, T., 2017. Investigation of EGR and Miller Cycle for NOx Emissions and Exhaust Temperature Control of a Heavy-Duty Diesel Engine. SAE Tech. Paper. 01, 2227.
5. 5. Wu, H.W., Hsu, T.T., He, J.Y., Fan, C.M., 2017. Optimal Performance and Emissions of Diesel/hydrogen-rich Gas Engine Varying Intake Air Temperature and EGR Ratio. Appl. Therm. Eng. 124, 381-392.
6. 6. Johnson, T.V. 2009. Review of Diesel Emissions and Control. Int. J. Eng. Res. 10(5), 275-285.
7. 7. Kalam, M.A., Masjuki, H.H., 2008. Testing Palm Biodiesel and NPAA Additives to Control NOx and CO While Improving Efficiency in Diesel Engines. Biomass and Bioener. 32(12), 1116-1122.
8. 8. Resitoglu, I.A, Keskin, A., 2017. Hydrogen Applications in Selective Catalytic Reduction of NOx Emissions from Diesel Engines. Int. J. Hydr. Ener. 42(36), 23389-23394.

9. 9. Ingole, A.K., Dixit, D., Dingare, S.V., 2017. A Review on Selective Catalytic Reduction Technique for Diesel Engine Exhaust After Treatment. Int. J. Curr. Eng. Tech. 7, 206-210.
10. 10. Stanciulescu, M., Charland, J.P., Kelly J.F. 2010. Effect of Primary Aminehydrocarbon Chain Length for the Selective Catalytic Reduction of NOx from Diesel Engine Exhaust. Fuel. 89, 2292–2298.
11. 11. Jiao, F., Hill, A.H., Harrison, A., Berko, A., Chadwick, A.V., Bruce, P.G., 2008. Synthesis of Ordered Mesoporous NiO with Crystalline Walls and a Bimodal Pore Size Distribution. J. Am. Chem. Soc. 130, 5262–5266.
12. 12. Zhang, Y., Zhao, X.C., Wang, Y., Zhou, L., Zhang, J., Wang, J., Wang, A., Zhang, T., 2013. Mesoporous Ti–W Oxide: Synthesis, Characterization and Performance in Selective Hydrogenolysis of Glycerol. J. Mater. Chem. A 1, 3724–3732.
13. 13. Rauch, D., Albrecht, G., Kubinski, D., Moos, R., 2015. A Microwave-based Method to Monitor the Ammonia Loading of Avanadiabased SCR Catalyst. Appl. Catal. B: Environ.165, 36–42.
14. 14. Oliveira, M.L.M., Silva, C.M., Tost, R.M., Farias, T.L., Lopez, A.J., Castellon E.R., 2011. Modelling of NOx Emission Factors from Heavy and Light-duty Vehicles Equipped with Advanced Aftertreatment Systems. Ener. Conv. Manag. 52, 2945–2951.
15. 15. Pang, L., Fan, C., Shao, L., Yi, J., Cai, X., Wang, J., Kang, M., Li, T., 2014. Effect of V2O5/WO3-TiO2 Catalyst Preparation Method on NOx Removal from Diesel Exhaust. Chinese J. Catal. 35, 2020–2028.
16. 16. Kim, P.S., Cho, B.K., Nam, I.S., Choung, J.W., 2016. Bifunctional Ag-based Catalyst for NOx Reduction with E-diesel Fuel. Chem Cat Chem. 6,1570-1574.
17. 17. Kang, M., Park, E.D., Kim, J.M., Yie, J.E., 2006. Cu–Mn Mixed Oxides for Low Temperature NO Reduction with NH3. Catal. Today. 111(3-4), 236-241.
18. 18. Wu, Z., Jin, R., Wang, H., Liu, Y. ,2009. Effect of Ceria Doping on SO2 Resistance of Mn/TiO2 for Selective Catalytic Reduction of NO with NH3 at Low Temperature. Catal. Commun. 10, 935–939.
19. 19. Kwak, J.H., Tonkyn, R., Tran, D., Mei, D., Cho, S.J., Kovarik, L., Lee, J.H., Peden, C.H.F., Szanyi, J., 2012. Size-Dependent Catalytic Performance of CuO on γ-Al2O3: NO Reduction versus NH3 Oxidation ACS Catal. 2, 1432–1440.