摘要
While Fe-based oxygen carriers(OC) are regarded to be promising for chemical looping combustion(CLC),the decrease of CO_2 selectivity during deep reduction process and the severe agglomeration of Fe_2O_3 often occur after multiple redox cycles due to the low oxygen mobility.Herein,Fe-substituted Bahexaaluminates(Ba Fe_xAl_(12)– xO_(19),denoted as BF_xA-H,x = 1 and 2) prepared by a modified two-step method exhibited not only higher amount of converted oxygen(Ot) and CH_4 conversion(77% and 81% vs.17%and 75%) than those prepared by the traditional co-precipitation method(BF_xA-C,x = 1 and 2) but also high CO_2 selectivity above 92% during the nearly whole reduction from Fe~(3+) to Fe~(2+).Furthermore,the BFxA-H exhibited the excellent recyclability during 50 cycles.The better performance was ascribed to the markedly enhanced oxygen mobility which resulted from dominant occupancy of Fe cations in Al(5) sites(Fe~5: 71% and 70% vs.49% and 41%) in mirror planes of hexaaluminate leading to larger amount of lattice oxygen coordinated with Fe~5(O–Fe~5)(0.45 and 0.85 mmol/g vs.0.31 and 0.50 mmol/g).The improvement of oxygen mobility also favored the preservation of chemical state of Fe cations in hexaaluminate structure in the re-oxidation step,resulting in the excellent recyclability of BF_xA-H.
While Fe-based oxygen carriers(OC) are regarded to be promising for chemical looping combustion(CLC),the decrease of CO_2 selectivity during deep reduction process and the severe agglomeration of Fe_2O_3 often occur after multiple redox cycles due to the low oxygen mobility.Herein,Fe-substituted Bahexaaluminates(Ba Fe_xAl_(12)– xO_(19),denoted as BF_xA-H,x = 1 and 2) prepared by a modified two-step method exhibited not only higher amount of converted oxygen(Ot) and CH_4 conversion(77% and 81% vs.17%and 75%) than those prepared by the traditional co-precipitation method(BF_xA-C,x = 1 and 2) but also high CO_2 selectivity above 92% during the nearly whole reduction from Fe~(3+) to Fe~(2+).Furthermore,the BFxA-H exhibited the excellent recyclability during 50 cycles.The better performance was ascribed to the markedly enhanced oxygen mobility which resulted from dominant occupancy of Fe cations in Al(5) sites(Fe~5: 71% and 70% vs.49% and 41%) in mirror planes of hexaaluminate leading to larger amount of lattice oxygen coordinated with Fe~5(O–Fe~5)(0.45 and 0.85 mmol/g vs.0.31 and 0.50 mmol/g).The improvement of oxygen mobility also favored the preservation of chemical state of Fe cations in hexaaluminate structure in the re-oxidation step,resulting in the excellent recyclability of BF_xA-H.
引文
[1]P.Markewitz,W.Kuckshinrichs,W.Leitner,J.Linssen,P.Zapp,R.Bongartz,A.Schreiber,T.E.Muller,Energy Environ.Sci.5(2012)7281-7305.
[2]E.M.Briz-López,M.J.Ramírez-Moreno,I.C.Romero-Ibarra,C.Gómez-Yá?ez,H.Pfeiffer,J.Ortiz-Landeros,J.Energy Chem.25(2016)754-760.
[3]C.Chen,S.Zhang,K.H.Row,W.-S.Ahn,J.Energy Chem.26(2017)868-880.
[4]M.E.Boot-Handford,J.C.Abanades,E.J.Anthony,M.J.Blunt,S.Brandani,N.Mac Dowell,J.R.Fernandez,M.C.Ferrari,R.Gross,J.P.Hallett,R.S.Haszeldine,P.Heptonstall,A.Lyngfelt,Z.Makuch,E.Mangano,R.T.J.Porter,M.Pourkashanian,G.T.Rochelle,N.Shah,J.G.Yao,P.S.Fennell,Energy Environ.Sci.7(2014)130-189.
[5]J.Adanez,A.Abad,F.Garcia-Labiano,P.Gayan,L.F.de Diego,Proc.Combust.Inst.38(2012)215-282.
[6]H.Tian,R.Siriwardane,T.Simonyi,J.Poston,Energy Fuels 27(2013)4108-4118.
[7]A.Fossdal,O.Darell,A.Lambert,E.Schols,E.Comte,R.Leenman,R.Blom,Energy Fuels 29(2015)314-320.
[8]Y.Zheng,K.Li,H.Wang,D.Tian,Y.Wang,X.Zhu,Y.Wei,M.Zheng,Y.Luo,Appl.Catal.B 202(2017)51-63.
[9]X.Cheng,K.Li,H.Wang,X.Zhu,Y.Wei,Z.Li,M.Zheng,D.Tian,Chem.Eng.J.328(2017)382-396.
[10]P.Puthiaraj,W.-S.Ahn,J.Energy Chem.26(2017)965-971.
[11]S.Bhavsar,M.Najera,R.Solunke,G.Veser,Catal.Today 228(2014)96-105.
[12]X.Zheng,L.Che,Y.Hao,Q.Su,J.Energy Chem.25(2016)101-109.
[13]Z.Gu,K.Li,H.Wang,S.Qing,X.Zhu,Y.Wei,X.Cheng,H.Yu,Y.Cao,Appl.Energy 163(2016)19-31.
[14]N.L.Galinsky,A.Shafiefarhood,Y.Chen,L.Neal,F.Li,Appl.Catal.B 164(2015)371-379.
[15]O.Mihai,D.Chen,A.Holmen,J.Catal.293(2012)175-185.
[16]L.-S.Fan,L.Zeng,S.Luo,AIChE J.61(2015)2-22.
[17]L.M.Neal,A.Shafiefarhood,F.Li,ACS Catal 4(2014)3560-3569.
[18]E.Jerndal,T.Mattisson,A.Lyngfelt,Chem.Eng.Res.Des.84(2006)795-806.
[19]Y.Zhang,E.Doroodchi,B.Moghtaderi,Energy Fuels 29(2015)337-345.
[20]S.Bhavsar,G.Veser,Ind.Eng.Chem.Res.52(2013)15342-15352.
[21]M.Ryden,E.Cleverstam,M.Johansson,A.Lyngfelt,T.Mattisson,AIChE J.56(2010)2211-2220.
[22]K.Li,H.Wang,Y.Wei,J.Chem.2013(2013)1-8.
[23]Z.Sun,Q.Zhou,L.S.Fan,Langmuir 29(2013)12520-12529.
[24]F.Li,Z.Sun,S.Luo,L.-S.Fan,Energy Environ.Sci.4(2011)876-880.
[25]F.Li,S.Luo,Z.Sun,X.Bao,L.-S.Fan,Energy Environ.Sci.4(2011)3661-3667.
[26]N.L.Galinsky,Y.Huang,A.Shafiefarhood,F.Li,ACS Sustain.Chem.Eng.1(2013)364-373.
[27]F.Liu,L.Chen,J.K.Neathery,K.Saito,K.Liu,Ind.Eng.Chem.Res.53(2014)16341-16348.
[28]D.D.Miller,R.Siriwardane,Energy Fuels 27(2013)4087-4096.
[29]S.Laassiri,N.Bion,F.Can,X.Courtois,D.Duprez,S.Royer,H.Alamdari,Cryst Eng Comm 14(2012)7733-7743.
[30]Y.Zhu,X.Wang,A.Wang,G.Wu,J.Wang,T.Zhang,J.Catal.283(2011)149-160.
[31]M.Machida,A.Sato,T.Kijima,H.Inoue,K.Eguchi,Catal.Today 26(1995)239-245.
[32]Y.Zhang,X.Wang,Y.Zhu,T.Zhang,Appl.Catal.B 129(2013)382-393.
[33]M.Machida,T.Shiomitsu,K.Eguchi,H.Haneda,H.Arai,J.Mater.Chem.2(1992)455-458.
[34]M.Machida,K.Eguchi,H.Arai,J.Catal.123(1990)477-485.
[35]M.Tian,A.Wang,X.Wang,Y.Zhu,T.Zhang,Appl.Catal.B 92(2009)437-444.
[36]J.Perez-Ramirez,M.Santiago,Chem.Commun.(2007)619-621.
[37]G.Groppi,C.Cristiani,P.Forzatti,J.Catal.168(1997)95-103.
[38]T.H.Gardner,J.J.Spivey,E.L.Kugler,A.Campos,J.C.Hissam,A.D.Roy,J.Phys.Chem.C 114(2010)7888-7894.
[39]T.Li,Y.Li,Ind.Eng.Chem.Res.47(2008)1404-1408.
[40]A.Baylet,S.Royer,P.Marécot,J.M.Tatibou?t,D.Duprez,Appl.Catal.B 77(2008)237-247.
[41]T.H.Gardner,J.J.Spivey,E.L.Kugler,D.Pakhare,Appl.Catal.A 455(2013)129-136.
[42]M.Tian,X.Wang,X.Liu,A.Wang,T.Zhang,AIChE J.62(2016)792-801.
[43]Z.Jiang,Z.Hao,J.Su,T.Xiao,P.P.Edwards,Chem.Commun.(2009)3225-3227.
[44]S.Laassiri,N.Bion,D.Duprez,S.Royer,H.Alamdari,Phys.Chem.Chem.Phys.16(2014)4050-4060.
[45]F.Huang,X.Wang,A.Wang,J.Xu,T.Zhang,Catal.Sci.Technol.6(2016)4962-4969.
[46]F.Huang,X.Wang,L.Li,X.Liu,J.Xu,C.Huang,T.Zhang,Catal.Sci.Technol.6(2016)7860-7867.
[47]Y.Zhu,X.Wang,G.Wu,Y.Huang,Y.Zhang,J.Wang,T.Zhang,J.Phys.Chem.C 116(2012)671-680.
[48]F.Menil,J.Phys.Chem.Solids 46(1985)763-789.
[49]C.R.Kurkjian,J.Non-Cryst.Solids 3(1970)157-194.
[50]S.Laassiri,N.Bion,D.Duprez,H.Alamdari,S.Royer,Catal.Sci.Technol.3(2013)2259-2269.
[51]P.Artizzu-Duart,J.M.Millet,N.Guilhaume,E.Garbowski,M.Primet,Catal.Today 59(2000)163-177.
[52]Z.Sun,Q.Zhou,L.S.Fan,Langmuir 29(2013)12520-12529.
[53]K.Liu,A.Q.Wang,W.S.Zhang,J.H.Wang,Y.G.Huang,J.Y.Shen,T.Zhang,J.Phys.Chem.C 114(2010)8533-8541.
[54]X.D.Wang,X.Q.Zhao,J.Y.Shen,X.Y.Sun,T.Zhang,L.W.Lin,Phys.Chem.Chem.Phys.4(2002)2846-2851.
[55]R.G.Burns,Hyperfine Interact 91(1994)739-745.