Ag-assisted CeO₂ catalyst for soot oxidation

Abstract

In this work, the Ag loaded Ce-based catalyst was synthesized (by the sol−gel method) and its performance was studied by TG, H₂-TPR, XRD, SEM, TEM, BET and XPS. The results show that Ag nanoparticles be successfully loaded onto the CeO₂ surface and the relative content of Ag nanoparticles is about 10.22 wt.% close to the theoretical value (10%). XPS shows that Ag nanoparticles induce a great number of oxygen vacancies in the CeO₂ lattice through the electronic transfer, and H₂-TPR indicates that the Ag-assisted CeO₂ catalyst exhibits a better reduction performance and Ag nanoparticles can promote O⁻ transform into O²⁻. The catalytic activity for soot oxidation was studied by TG under air atmosphere and the activity was found to be obviously enhanced when Ag nanoparticles be load on the surface of CeO₂ (T₁₀ = 386 °C, T₉₀ = 472.5 °C, T_m = 431 °C). The reaction mechanism was also presented and O₂⁻ species is regarded as the determinant factor for the catalytic activity.

Keywords

soot oxidation / CeO ₂ / oxygen vacancy

References

[1] He H, Lin X, Li S, . The key surface species and oxygen vacancies in MnO_x(0.4)–CeO₂ toward repeated soot oxidation. Applied Catalysis B: Environmental, 2018, 223: 134–142

[2] Li Q, Wang X, Chang W, . Promotional effects of cerium doping and NO_x on the catalytic soot combustion over MnMgAlO hydrotalcite-based mixed oxides. Journal of Rare Earths, 2014, 32(2): 176–183

[3] Messerer A, Niessner R, Pöschl U. Comprehensive kinetic characterization of the oxidation and gasification of model and real diesel soot by nitrogen oxides and oxygen under engine exhaust conditions: Measurement, Langmuir–Hinshelwood, and Arrhenius parameters. Carbon, 2006, 44(2): 307–324

[4] Ma C, Gao J, Zhong L, . Experimental investigation of the oxidation behaviour and thermal kinetics of diesel particulate matter with non-thermal plasma. Applied Thermal Engineering, 2016, 99: 1110–1118

[5] Dhal G C, Dey S, Mohan D, . Simultaneous abatement of diesel soot and NOX emissions by effective catalysts at low temperature: An overview. Catalysis Reviews, 2018, 60(3): 437–496

[6] Fino D, Bensaid S, Piumetti M, . A review on the catalytic combustion of soot in Diesel particulate filters for automotive applications: From powder catalysts to structured reactors. Applied Catalysis A: General, 2016, 509: 75–96

[7] Diehl F, Barbier J, Duprez D, . Catalytic oxidation of heavy hydrocarbons over Pt/Al₂O₃. Oxidation of C10+ solid hydrocarbons representative of soluble organic fraction of Diesel soots. Applied Catalysis A: General, 2015, 504: 37–43

[8] Ji F, Men Y, Wang J, . Promoting diesel soot combustion efficiency by tailoring the shapes and crystal facets of nanoscale Mn₃O₄. Applied Catalysis B: Environmental, 2019, 242: 227–237

[9] Urán L, Gallego J, Li W Y, . Effect of catalyst preparation for the simultaneous removal of soot and NO_x. Applied Catalysis A: General, 2019, 569: 157–169

[10] Yang L, Zhang C, Shu X, . The mechanism of Pd, K co-doping on Mg–Al hydrotalcite for simultaneous removal of diesel soot and NO_x in SO₂-containing atmosphere. Fuel, 2019, 240: 244–251

[11] Jampaiah D, Velisoju V K, Devaiah D, . Flower-like Mn₃O₄/CeO₂ microspheres as an efficient catalyst for diesel soot and CO oxidation: Synergistic effects for enhanced catalytic performance. Applied Surface Science, 2019, 473: 209–221

[12] Shen Q, Lu G, Du C, . Role and reduction of NO_x in the catalytic combustion of soot over iron–ceria mixed oxide catalyst. Chemical Engineering Journal, 2013, 218: 164–172

[13] Lu P, Li C, Zeng G, . Research on soot of black smoke from ceramic furnace flue gas: characterization of soot. Journal of Hazardous Materials, 2012, 199–200: 272–281

[14] Katta L, Sudarsanam P, Thrimurthulu G, . Doped nanosized ceria solid solutions for low temperature soot oxidation: Zirconium versus lanthanum promoters. Applied Catalysis B: Environmental, 2010, 101(1–2): 101–108

[15] Wu Y, Li L, Chu B, . Catalytic reduction of NO by CO over B-site partially substituted LaM_0.25Co_0.75O₃ (M = Cu, Mn, Fe) perovskite oxide catalysts: The correlation between physicochemical properties and catalytic performance. Applied Catalysis A: General, 2018, 568: 43–53

[16] Lykaki M, Pachatouridou E, Carabineiro S A C, . Ceria nanoparticles shape effects on the structural defects and surface chemistry: Implications in CO oxidation by Cu/CeO₂ catalysts. Applied Catalysis B: Environmental, 2018, 230: 18–28

[17] Mukherjee D, Reddy B. M Noble metal-free CeO₂-based mixed oxides for CO and soot oxidation. Catalysis Today, 2018, 309: 227–235

[18] Zhang H, Hu W, Zhou C, . A new understanding of CeO₂–ZrO₂ catalysts calcinated at different temperatures: Reduction property and soot-O₂ reaction. Applied Catalysis A: General, 2018, 563: 204–215

[19] Nascimento L F, Lima J F, de Sousa Filho P C, . Effect of lanthanum loading on nanosized CeO₂–ZnO solid catalysts supported on cordierite for diesel soot oxidation. Journal of Environmental Sciences (China), 2018, 73: 58–68

[20] Zhai G, Wang J, Chen Z, . Highly enhanced soot oxidation activity over 3DOM Co₃O₄–CeO₂ catalysts by synergistic promoting effect. Journal of Hazardous Materials, 2019, 363: 214–226

[21] Wang H, Jin B, Wang H, . Study of Ag promoted Fe₂O₃@CeO₂ as superior soot oxidation catalysts: The role of Fe₂O₃ crystal plane and tandem oxygen delivery. Applied Catalysis B: Environmental, 2018, 237: 251–262

[22] Liu L, Shi J, Wang R, . Fabrication of double-shelled Fe₂O₃/CeO₂ boxes from CeO₂-modified Prussian blue and their enhanced performances for CO removal and water treatment. Journal of Alloys and Compounds, 2017, 725: 544–556

[23] Nie L, Mei D, Xiong H, . Activation of surface lattice oxygen in single-atom Pt/CeO₂ for low-temperature CO oxidation. Science, 2017, 358(6369): 1419–1423

[24] Huang X, Zhao G, Chang Y, . Nanocrystalline CeO_2−δ coated β-MnO₂ nanorods with enhanced oxygen transfer property. Applied Surface Science, 2018, 440: 20–28

[25] Gao Y, Wu X, Nord R, . Sulphation and ammonia regeneration of a Pt/MnO_x–CeO₂/Al₂O₃ catalyst for NO_x-assisted soot oxidation. Catalysis Science & Technology, 2018, 8(6): 1621–1631

[26] Wei Y, Liu J, Zhao Z, . Structural and synergistic effects of three-dimensionally ordered macroporous Ce_0.8Zr_0.2O₂-supported Pt nanoparticles on the catalytic performance for soot combustion. Applied Catalysis A: General, 2013, 453: 250–261

[27] Wei Y, Liu J, Zhao Z, . The catalysts of three-dimensionally ordered macroporous Ce_1−xZr_xO₂-supported gold nanoparticles for soot combustion: The metal-support interaction. Journal of Catalysis, 2012, 287: 13–29

[28] Aneggi E, Wiater D, de Leitenburg C, . Shape-dependent activity of ceria in soot combustion. ACS Catalysis, 2014, 4(1): 172–181

[29] Ai L, Wang Z, Gao Y, . Effect of surface and bulk palladium doping on the catalytic activity of La₂Sn₂O₇ pyrochlore oxides for diesel soot oxidation. Journal of Materials Science, 2019, 54(6): 4495–4510

[30] Jin B, Wei Y, Zhao Z, . Three-dimensionally ordered macroporous CeO₂/Al₂O₃-supported Au nanoparticle catalysts: Effects of CeO₂ nanolayers on catalytic activity in soot oxidation. Chinese Journal of Catalysis, 2017, 38(9): 1629–1641

[31] Liu S, Wu X, Tang J, . An exploration of soot oxidation over CeO₂–ZrO₂ nanocubes: Do more surface oxygen vacancies benefit the reaction? Catalysis Today, 2017, 281: 454–459

[32] Liu S, Wu X, Liu W, . Soot oxidation over CeO₂ and Ag/CeO₂: Factors determining the catalyst activity and stability during reaction. Journal of Catalysis, 2016, 337: 188–198

[33] Kim W K, Han D W, Ryu W H, . Effects of Cl doping on the structural and electrochemical properties of high voltage LiMn_1.5Ni_0.5O₄ cathode materials for Li-ion batteries. Journal of Alloys and Compounds, 2014, 592: 48–52

[34] Shao W, Wang Z, Zhang X, . Promotion effects of cesium on perovskite oxides for catalytic soot combustion. Catalysis Letters, 2016, 146(8): 1397–1407

[35] Jin B, Wu X, Weng D, . Roles of cobalt and cerium species in three-dimensionally ordered macroporous Co_xCe_1−xO_δ catalysts for the catalytic oxidation of diesel soot. Journal of Colloid and Interface Science, 2018, 532: 579–587

[36] Guo X, Meng M, Dai F, . NO_x-assisted soot combustion over dually substituted perovskite catalysts La_1−xK_xCo_1−yPd_yO_3−δ. Applied Catalysis B: Environmental, 2013, 142–143: 278–289

[37] Liu M, Wu X, Liu S, . Study of Ag/CeO₂ catalysts for naphthalene oxidation: Balancing the oxygen availability and oxygen regeneration capacity. Applied Catalysis B: Environmental, 2017, 219: 231–240

RIGHTS & PERMISSIONS

Higher Education Press and Springer-Verlag GmbH Germany, part of Springer Nature