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Experimental Setup Fixed-bed quartz tube reactor: h = 20 cm d = 0.6 cm m Cat = 0.2 g Reaction Conditions: GHSV = 30,000 h -1 c(NO) = 500 ppm c(NH 3 ) = 575 ppm = 120 mL min -1 c(O 2 ) = 4 Vol.-% Selective catalytic reduction of NO x by NH 3 (NH 3 -SCR) is used as an efficient technology to eliminate NO x from the diesel exhausts. Several research groups have reported property-activity relationships for Cu-containing molecular sieves, e.g., Cu-ZSM-5 [1] or Cu-SSZ-13 [2]. Additionally, mesopores have been shown to provide high dispersion of the metal component in comparison to conventional microporous materials and thus also enhanced activity and N 2 selectivity in NH 3 -SCR. However, the catalytic properties of Cu-Y has been less extensively investigated compared to other Cu-containing zeolites [3]. In view of these challenges, zeolite Y was synthesized and exposed to a variety of acid or base treatments [4]. In this study, the effect of the structural and textural properties of the zeolites on the nature and distribution of copper species and the associated catalytic properties were investigated over hierarchical micro-/mesoporous Cu-Y. Result and Discussion NH 3 -SCR over Copper-exchanged Zeolite Y R. S. R. Suharbiansah a , K. Góra-Marek b , K. Pyra b , R. Gläser a , M. Jabłońska a a Institute of Chemical Technology, Universität Leipzig, Linnestr. 3, 04103, Leipzig, Germany b Faculty of Chemistry, Jagiellonian University in Krakow, Gronostajowa 2, 30-387 Krakow, Poland M. Sc. Rujito Sesariojiwandono Ridho S. Institute of Chemical Technology Linnéstr. 3 | 04103 Leipzig +49 341 97 36318 [email protected] Introduction References Institute of Chemical Technology Contact Conclusions Across the investigated materials, copper species were mainly present as isolated cations (the light blue colored ion-exchanged materials) and bulky CuO clusters Cu-Y (Na 2 H 2 EDTA) The Cu 2+ species serve as active sites for NH 3 -SCR, while NH 3 is oxidized to NO over CuO sites CuY Cu-Y (DEA) Cu-Y (EDTA) Cu-Y (NaOH) 0 2 4 6 8 10 Na content / wt.-% Cu content / wt.-% 0 2 4 6 8 10 Copper particles are dispersed homogenously throughout the zeolite samples Cu-Y 30 μm 2 μm Experimental Section ሶ V 4NO + 4NH 3 + O 2 4N 2 + 6H 2 O 2NO 2 + 4NH 3 + O 2 3N 2 + 6H 2 O Catalytic Investigations Selective Catalytic Reduction [1] J. Zhao, G. Wang, L. Qin, H. Li, Y. Chen, B. Liu, Catal. Commun. 73 (2016) 98-102. [2] S. Shrestha, M.P. Harold, K. Kamasamudram, A. Kumar, L. Olsson, K. Leistner, Catal. Today 267 (2016) 130-144. [3] A.A. Dabbawala, V. Tzitzios, K. Sunny, K. Polychronopoulou, G. Basina, I. Ismail, V. Pillai, A. Tharalekshmy, S. Stephen, S.M. Alhassan, Surf. Coat. Technol. 350 (2018) 369-375. [4] M. Rutkowska, I. Pacia, S. Basąg, A. Kowalczyk, Z. Piwowarska, M. Duda, K.A. Tarach, K. Góra-Marek, M. Michalik, U. Díaz, L. Chmielarz, Microporous Mesoporous Mater. 246 (2017) 193-206. Acknowledgements: 100 150 200 250 300 350 400 450 0 5 10 15 20 25 30 35 Cu-Y Cu-Y (DEA) Cu-Y (Na 2 H 2 EDTA) Cu-Y (NaOH) Cu-Y (TPAOH) N 2 O yield / % Temperature / o C 200 300 400 500 600 700 800 900 Cu + /Cu 2+ CT Kubelka-Munk function / arb.u. Wavelength / cm -1 Cu-Y Cu-Y (DEA) Cu-Y (Na 2 H 2 EDTA) Cu-Y (NaOH) Cu-Y (TPAOH) Cu 2+ d-d Charge transfer (CT) from framework oxygen to isolated Cu + and/or Cu 2+ 2200 2150 2100 2050 Absorbance / arb.u. Wavenumber / cm -1 2130 2142 Cu + oxo (CO) Cu + exch (CO) 2155 2179 Cu + exch (CO) 2 2151 Cu-Y Cu-Y (DEA) Cu-Y (Na 2 H 2 EDTA) Cu-Y (NaOH) Cu-Y (TPAOH) CO sorption revealed monocarbonyls and dicarbonyls of Cu + in the exchange positions (Cu + exch (CO), Cu + exch (CO) 2 ) and monocarbonyls of Cu + oxo-species (Cu + oxo (CO). d-d transition - presence of aggregated CuO x The N 2 O yield does not vary significantly within the tested catalysts and does not exceed more than 30% in the studied temperature range of 100- 450 ̊C Catalytic tests SCR Catalyst Zeolite Y • Catalyst morphology 50 100 150 200 250 300 350 400 450 500 20 40 60 80 100 NO conversion / % Temperature / o C Cu-Y Cu-Y (DEA) Cu-Y (Na 2 H 2 EDTA) Cu-Y (NaOH) Cu-Y (TPAOH) • Copper species in catalysts • Catalyst composition Treatment with: • DEA – diethylamine; NaOH – sodium hydroxide • Na 2 H 2 EDTA – disodium ethylenediamine tetraacetate • TPAOH – tetrapropylammonium hydroxide Cu-Y (DEA) Cu-Y (NaOH) Cu-Y (Na 2 H 2 EDTA) Cu-Y (TPAOH)
