La-hexaaluminate catalyst for methane catalytic combustion was synthesized by a reverse microemulsion.Pseudo-ternary phase diagrams of a quaternary microemulsion system of sodium dodecyl sulfate (SDS),n-pentanol,n-octane,and water (or Al(NO3)3 solution) were presented.The effects of alcohol chain length,cosurfactant-to-surfactant ratio,and salt concentration on the formation and stability of the microemulsion system were studied.The phenomenon that the conductivity changed with water supported the phase behavior of the microemulsion system.La(Mnx/Fex)Al12-xO19-δcatalysts,applied in methane combustion and with high-temperature stability,were synthesized within the stable areas of the phase diagram of the microemulsion system,when SDS was chosen as surfactant,n-pentanol as cosurfactant,and n-octane as oil phase.The physical properties and structure of the catalysts were characterized by BET method,transmission electron microscope (TEM),and X-ray diffraction (XRD).A micro-fixed-bed reactor was used to measure the catalytic activity of hexaaluminates in methane combustion.The results show that the reverse microemulsions can be used to produce discrete La-hexaaluminate nanoparticles that display excellent methane combustion activity owing to their high surface area and high thermal stability.
参考文献
| [1] | Sara Eriksson;Ulf Nylen;Sergo Rojas;Magali Boutonnet .Preparation of catalysts from microemulsions and their applications in heterogeneous catalysis[J].Applied Catalysis, A. General: An International Journal Devoted to Catalytic Science and Its Applications,2004(2):207-219. |
| [2] | YU Ying,DU Feipeng,MA Lili,LI Jialin,ZHUANG Yuanyi,QI Xinhua.Synthesis of Cu2O nanowhiskers with CTAB as a template in water-in-oil microemulsion system[J].稀有金属（英文版）,2005(03):283-287. |
| [3] | Bai S L;Wang L S;Shi B J .Synthesis of hexaaluminate catalysts for methane combustion by reverse rnicroemulsion medium[J].Science China(Earth Sciences),2009,52(01):31. |
| [4] | Vishal C;Pushan A;Chattopadhyay S;Maitra A N .Preparation of acicular γ-Fe2O3 particles from a microemulsion-mediated reaction[J].Materials Letters,1996,26(01):21. |
| [5] | Zarur AJ.;Ying JY. .Reverse microemulsion synthesis of nanostructured complex oxides forcatalytic combustion[J].Nature,2000(6765):65-67. |
| [6] | Zarur AJ.;Ying JY.;Hwu HH. .Reverse microemulsion-mediated synthesis and structural evolution of barium hexaaluminate nanoparticles[J].Langmuir: The ACS Journal of Surfaces and Colloids,2000(7):3042-3049. |
| [7] | Yu J C;Yu J G;Zhao J C .Enhanced photocatalytic activity of mesoporous and ordinary TiO2 thin films by sulfuric acid treatment[J].Applied Catalysis B:Environmental,2002,36:31. |
| [8] | Watt SL.;Biggs S.;Tunaley D. .The formation of water-in-oil microemulsions using a concentrated saline aqueous phase[J].Colloids and Surfaces, A. Physicochemical and Engineering Aspects,1998(1/3):25-33. |
| [9] | Cui Z G;Yin F S.Microemulsion Technique and Application[M].Publishing Company of Chinese Light Industry,Beijing,2001:179. |
| [10] | Lam A C;Falk N A;Schechter R S .The thermodynamics of nicroemulsions[J].Journal of Colloid and Interface Science,1987,120(01):30. |
| [11] | Eicke H F;Borkovec M;DasGupta D .Conductivity of water-in-oil microemulsions:a quantitative charge fluctuation model[J].Journal of Physical Chemistry,1989,93:314. |
| [12] | Fletcher P D I;Robinson B H .Dynamic processes in water in oil microemulsion[J].Journal of Physical Chemistry,1981,85:863. |
| [13] | Lada A;Lang L;Zana R .Relation between electric percolation and rate constant for exchange of material between droplets in water in oil microemulsions[J].Journal of Physical Chemistry,1989,93:10. |
| [14] | Groppi G;Belloto M;Cristian C;Forzatti P,and Villa P L .Preparation and characterization of hexaaluminate-based materials for catalytic combustion[J].Applied Catalysis A:General,1993,104(02):101. |
| [15] | Naoufal D.;Garbowski E.;Brulle Y.;Primet M.;Millet JM. .Synthesis, structure and catalytic properties of Fe-substituted barium hexaaluminates[J].Catalysis Letters,1998(3):141-148. |
| [16] | Bellotto M.;Cristiani C.;Forzatti P.;Groppi G.;Artioli G. .On the crystal structure and cation valence of Mn in Mn-substituted Ba-beta-Al2O3[J].Journal of Catalysis,1998(2):597-605. |
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