Communication presented at the International Symposium on Air & Water Pollution Abatement Catalysis - AWPAC 2014. Kraków, Poland, 1-5 September 2014Fundação para a Ciência e a Tecnologia. GDF Sue

Capela, Sandra

Costa, Patrick Da

Ferreira, Ana Paula

Grzybek, Teresa

Henriques, Carlos

Mendes, Acácio Nobre

Motak, Monika

Ribeiro, M. Filipa

Tlałka, Ilona

English

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The effect of La in            PdCe-zeolite catalysts for NOx-SCR with CH4Cracow, 01-05.09.2014Ilona Tlałka, Ana Paula Ferreira, Acácio Nobre Mendes,            Sandra Capela, Carlos Henriques, Patrick Da Costa, Monika Motak, Teresa Grzybek, M.  Filipa Ribeiro1Work purpose• The main goal of this work was to develop zeolite- basedcatalysts, showing a good catalytic behavior for DeNOxreduction with methane as reductant, even in thepresence of water.• Catalysts consisting of La, Ce and Pd, have been studied.• Metals combination, the amount and the order of Laintroduction in the catalysts were considered.2ExperimentalCatalystsNOx plantH2-TPRDRS UV-VisPowderXRD 3Test conditionsNOx plantSCR conditions:-1000ppm CH4-1000ppm NO  -7% OFlow rate= 250cm3 min-1 GHSV= 40000h-12-2% H2OCatalytic tests were performed using the following cycles:(1) a run under dry conditions, from 300ºC to 500ºC – 1st isothermal dry,(2)  a run under water vapor (2% vol. H2O), from 300ºC to 500ºC – isothermal wet,(3) a 2nd run in dry conditions after water test, from 300ºC-500ºC – 2nd isothermal dry.4PdCeLa-HBEAPdCeLa-HBEAcatalystsHBEA(Si/Al = 12.5)La(2.67)-HBEA             (SSIE)Ce(2)La(2.67)-HBEA       (IWI)La(5.35)-HBEA (SSIE)Ce(2)La(5.35)-HBEA (IWI)NH4BEA (Si/Al=12.5)La(2.2)-HBEA (IE)Ce(2)La(2.2)-HBEA             (IWI)Pd(0.5)Ce(2)La(2.67)-HBEA (IWI)Pd(0.5)Ce(2)La(5.35)-HBEA (IWI)Pd(0.5)Ce(2)La(2.2)-HBEA (IWI)• Different amounts of La introduced using different methods,• Equal Ce and Pd amount (2 wt.% and 0.5 wt.%, respectively), intoduced into all Lacatalysts,• The same method of Pd and Ce ions introduction  incipiente wetnessimpregnation.5Intensity (a.u.)XRD patterns for La(2.67)-HBEA and CeLa(2.67)-HBEA catalystsand tri-metallic PdCeLa(2.67)-HBEA catalystLa(2.67)-HBEACeLa(2.67)-HBEAPdCeLa(2.67)-HBEA5 10 15 20 25 30 35 40Intensity (a.u.)2θ (º)HBEA• Crystallinity was not affected by metal exchanged.6H2-TPR profiles of tri-metallic PdCeLa –HBEA catalystsTCD signal (a. u.)PdCeLa(2.2)-HBEA PdCeLa(5.35)-HBEA • 100oC  PdO species ininteractions with CeO2,• 130oC  reduction of Ce onthe surface,• 300-400oC  reduction of0 100 200 300 400 500 600 700 800 900 1000TCD signal (a. u.)Temperature (ºC)PdCeLa(2.67)-HBEAsurface Ce oxide species,• 600oC  reduction of bulkoxygen of Ce species,• 900oC  reduction of cerium(III) oxides 1-5.71 Saleh M. Saqer, Dimitris I. Kondarides, Xenophon E. Verykios, Applied Catalysis B: Environmental Vol. 103, (2011), 275–286.2 Córdoba L.F., Flytzani-Stephanopoulos M., Montes de Correa C., Applied Catalysis B: Environmental Vol. 33, (2001), 25–33.3 Feio L.S.F., Hori C.E., Damyanova S., Noronha F.B., Cassinelli W.H., Marques C.M.P., Bueno J.M.C., Applied Catalysis A: General Vol. 316, (2007), 107–116.4 WeyrichP.A., Trevin˜o H., Hölderich W.F., Sachtler W.M.H., Applied Catalysis A: General Vol. 163, (1997), 31–44.5 Yue L., He C., Zhang X., Li P., Wang Z., Wang H., Hao Z., Journal of Hazardous Materials Vol.244-245, (2013), 613-620.Diffuse reflectance UV-vis spectra at room temperature for trimetallic PdCeLa-HBEA catalystsF(R) (a.u.)PdCeLa(5.35)-HBEA PdCeLa-HBEA catalysts• 210 nm   disperse Ce3+ species,• 240nm    palladium clusters,• 260 nm   4f-5d transitions of Ce3+200 400 600 800F(R) (Wavelenght (nm)PdCeLa(2.2)-HBEA PdCeLa(2.67)-HBEA ions,• 310 nm  cerium (IV) oxides,• 500nm  palladium oxides 2-5.82 Córdoba L.F., Flytzani-Stephanopoulos M., Montes de Correa C., Applied Catalysis B: Environmental Vol. 33, (2001), 25–33.3 Feio L.S.F., Hori C.E., Damyanova S., Noronha F.B., Cassinelli W.H., Marques C.M.P., Bueno J.M.C., Applied Catalysis A: General Vol. 316, (2007), 107–116.4 WeyrichP.A., Trevin˜o H., Hölderich W.F., Sachtler W.M.H., Applied Catalysis A: General Vol. 163, (1997), 31–44.5 Yue L., He C., Zhang X., Li P., Wang Z., Wang H., Hao Z., Journal of Hazardous Materials Vol.244-245, (2013), 613-620.NOx SCR steady-state catalytic test results, over tri-metallic catalystsPdCeLa(2.67)-HBEA, PdCeLa(2.2)-HBEA and PdCeLa(5.35)-HBEA15202530Conversion of NO into N2(%)15202530onversion  into CO2 (%)NOx conversion into N2 CH4 conversion into CO20510300 350 400 450 500Conversion of NO into NTemperature (oC)0510300 350 400 450 500Total conversion  into Temperature (oC)• The best catalytic performance was observed over PdCeLa(2.67)-HBEA catalyst.  9Conversions during the whole catalytic cycle, obtained over PdCeLa-HBEA catalysts           Isothermal, Isothermal wet ,  Isothermal 2nd dry15202530Conversion of NO  into N2 (%)15202530Conversion of NO  into N2 (%)202530Conversion of NO into N2 (%)NOx  N2PdCeLa(2.2)-HBEA PdCeLa(5.35)-HBEA PdCeLa(2.67)-HBEA 0510300 350 400 450 500Conversion of NO  into NTemperature (ºC)0510300 350 400 450 500Conversion of NO  into NTemperature (oC)051015300 350 400 450 500Conversion of NO into NTemperature (ºC)• Stability of all presented PdCeLa-HBEA was greatly affected by water presence,• Initial conversion obtained during 1st isothermal tests, were not restored after thereaction with 2% of water in the reaction mixture.10Conversions during the whole catalytic cycle, obtained over PdCeLa-HBEA catalysts           Isothermal, Isothermal wet ,  Isothermal 2nd dryCH4  CO2PdCeLa(2.2)-HBEA PdCeLa(5.35)-HBEA PdCeLa(2.67)-HBEA 15202530onversion  into CO2 (%)15202530onversion  into CO2 (%)15202530onversion  into CO2 (%)0510300 350 400 450 500Total conversion  into Temperature (oC)0510300 350 400 450 500Total conversion  into Temperature (oC)• All trimetallic catalysts that have been studied during these researches, showed betterconversions for the reaction of methane combustion.110510300 350 400 450 500Total conversion  Temperature (ºC)NOx conversion into N2 during 1stisothermal catalytic testLa(2.67)-HBEA, CeLa(2.67)-HBEA, PdCeLa(2.67)-HBEANOx conversion into N2 during 2ndisothermal catalytic test 1520NO intoN2(%)1520intoN2(%)Results obtained over La(2.67)-HBEA and CeLa(2.67)-HBEA catalystsvs tri-metallic PdCeLa(2.67)-HBEA0510300 350 400 450 500ConversionofNO Temperature (oC)0510300 350 400 450 500ConversionofNOTemperature (oC)• Introduction of Ce did not produced the expected improvement in catalytic activity.This aim was observed only after the introduction of palladium.12CH4 conversion into CO2 during 1stisothermal catalytic testCH4 conversion into CO2 during 2ndisothermal catalytic testLa(2.67)-HBEA, CeLa(2.67)-HBEA, PdCeLa(2.67)-HBEA202530intoCO2(%)202530intoCO2(%)Results obtained over La(2.67)-HBEA and CeLa(2.67)-HBEA catalystsvs tri-metallic PdCeLa(2.67)-HBEA051015300 350 400 450 500Total conversionintoTemperature (oC)051015300 350 400 450 500Total conversionTemperature (oC)• Presented catalysts did not recover the initial activity after water test,• During 2nd isothermal test, monometallic La catalyst had the best catalytic behavior,as well as for the reaction of NOx reduction.13PdLa-HBEALaPd-HBEAHBEA (Si/Al=12.5)La(5.35)-HBEA[Solid State Ion Exchange]Pd(0.5)-HBEA[Ion Exchange]Pd(0.5)La(5.35)-HBEA[Incipient Wetness Impregnation]La(5.35)Pd(0.5)-HBEA[Solid State Ion Exchange] Different order of exchanged metals, Different method of Pd ions introduction.14H2-TPR profiles of bi-metallic PdLa –HBEA catalystsTCD signal (a. u.)La(5.35)Pd(0.5)-HBEA • 100oC  reduction of PdOspecies in the main channel ofthe zeolite structure,0 100 200 300 400 500 600 700 800 900 1000TCD signal (a. u.)Temperature (ºC)Pd(0.5)La(5.35)-HBEA • 300 to 500oC  reduction ofPdO species on ion exchangedpositions 9, 10.159 Zhang Z., Xu L., Wang Z., Xu Y., Chen Y., Journal of Natural Gas Chemistry, 19 (2010 ), 417–421.10Park Y.K., Lee J.W., Lee C.W., Park S.E., Journal of Molecular Catalysis A: Chemical Vol. 158, (2000), 173–179.Diffuse reflectance UV-vis spectra at room temperature for bi-metallic PdLa-HBEAcatalystsF(R) (a.u.)Pd(0.5)La(5.35)-HBEAPdLa-HBEA catalysts• 240nm formation of palladium clusters,• 340nm   formation of palladium chlorides in the surface of the 200 300 400 500 600 700 800F(R) (Wavelenght (nm)La(5.35)Pd(0.5)-HBEA support,• 400 - 500nm  presence of palladiumoxides 7.167 Park Y.K., Lee J.W., Lee C.W., Park S.E., Journal of Molecular Catalysis A: Chemical Vol. 158, (2000), 173–179.NOx conversion into N2 CH4 conversion into CO2NOx SCR steady-state catalytic test results, over bi-metallic Pd(0.5)La(5.35)-HBEAand La(5.35)Pd(0.5)-HBEA catalysts101520ofNOxintoN2 (%)202530354045conversionintoCO2(%)05300 350 400 450 500ConversionTemperature (ºC)051015300 350 400 450 500Total conversionTemperature (ºC)• Catalyst prepared by introducing La before Pd ions (blue line), showed bettercatalytic performance during NOx reduction.17Conversions during the whole catalytic cycle, obtained over PdLa-HBEA catalyst                Isothermal, Isothermal wet ,  Isothermal 2nd dry05101520300 350 400 450 500ConversionofNOintoN2 (%)05101520300 350 400 450 500ConversionofNOintoN2 (%)• Catalytic activity for PdLa-HBEAcatalysts was restored only for thereaction of methane combustion.La(5.35)Pd(0.5)-HBEA Pd(0.5) La(5.35)-HBEA Temperature (ºC) Temperature (ºC)NOx conversion into N2051015202530354045300 350 400 450 500Total conversionintoCO2(%)Temperature (ºC)051015202530354045300 350 400 450 500Total conversionintoCO2(%)Temperature (ºC)CH4 conversion into CO218La(5.35)Pd(0.5)-HBEA Pd(0.5) La(5.35)-HBEA Conclusions• The catalytic activities observed in all BEA catalysts were relatively low, in fact, theconversion for NO into N2 were below 20% and the total CH4 combustion reachesmaximum values around 40%,• All of the samples exhibit a greatly decreased in the catalytic activity during the testunder water conditions, which clearly shows the negative impact of water in gasstream,• Only three catalysts had recovered their initial activity after contacting with water ingas stream and it may be attributed to the modification in the location of the ionsor to a change in the strength of available acid sites,19• Most of the prepared catalysts had no acid sites after the last exchange and thismight be contributing for the impossibility of catalysts to recover from the contactwith water,• Concerning the stability of the catalysts Ce appears to play an important role whenConclusionsit is present in bi-metallic catalysts.20I would like to thank Professor Filipa Ribeiro, who gave me an opportunity to work inthe Laboratory of Zeolites and for all Her efforts in helping me to achieve desiredobjectives,Professor Ana Paula Ferreira great thanks for being my mentor, for sharing with meHer scientific knowledge and for all the support she always gave me,For Acácio Mendes, who have introduced me into work in the laboratory, who was mytutor during my first month in the laboratory. For all His time he devoted for solvingmy problems, for supporting me with my ideas, and for sharing with me His scientificAcknowledgmentsknowledge,For GDF-SUEZ company, thanks to which the realization of this project was possible,For Dr Monika Motak, for all Her ideasand suggestions she gave to me during theseresearch,Special thanks to Prof. Teresa Grzybek for all the effort she put to make my internshipbecame possible.21THANK YOU FOR YOUR ATTENTION22

The effect of La in PdCe-zeolite catalysts for NOx-SCR with CH4

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The effect of La in PdCe-zeolite catalysts for NOx-SCR with CH4

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