Stability and excitation of potassium promoter in iron catalysts - the role of KFeO2 and KAlO2 phases
作者： Andrzej Kotarba , Andrzej Barański , Stanisław Hodorowicz , Jerzy Sokołowski , Andrzej Szytuła
关键词: Activation energy 、 Desorption 、 Chemistry 、 Field desorption 、 Chemical state 、 Thermal desorption 、 Excited state 、 Physical chemistry 、 Inorganic chemistry 、 Ionic bonding 、 Rydberg atom
摘要: Well‐characterized catalyst model compounds of KAlO2 and KFeO2 are investigated by thermal desorption potassium from the material. The desorbing fluxes ions, atoms highly excited states (field ionizable Rydberg states) were studied with surface field ionization detectors in a vacuum apparatus. From Arrhenius plots activation energies for K K+ determined. chemical state at surfaces is concluded to be: ionic on (with barrier 1.76 eV) covalent (barrier 2.73 eV). These results agree data obtained earlier industrial catalysts ammonia styrene production. They interpreted terms Schottky cycle, which completed fails KFeO2. This failure indicates non‐equilibrium process. only found desorb KFeO2, agreement suggestion that such some way responsible catalytic activity.
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A. Barański, R. Dziembaj, A. Kotarba, A. Goŀbiowski, Z. Janecki, J.B.C. Pettersson, Deactivation of iron catalyst by water-potassium thermal desorption studies Studies in Surface Science and Catalysis. ,vol. 126, pp. 229- 236 ,(1999) , 10.1016/S0167-2991(99)80471-6
Takenori Hirano, Dehydrogenation of ethylbenzene over potassium-promoted iron oxide containing cerium and molybdenum oxides Applied Catalysis. ,vol. 28, pp. 119- 132 ,(1986) , 10.1016/S0166-9834(00)82497-5
J�rgen Lundin, Klas Engvall, Leif Holmlid, P. Govind Menon, Mechanism of potassium loss by desorption from an iron oxide catalyst for the styrene process Catalysis Letters. ,vol. 6, pp. 85- 93 ,(1990) , 10.1007/BF00764056
Leif Holmlid, Complex Kinetics of Desorption and Diffusion. Field Reversal Study of K Excited-State Desorption from Graphite Layer Surfaces Journal of Physical Chemistry A. ,vol. 102, pp. 10636- 10646 ,(1998) , 10.1021/JP9823796
T YOSHIOKA, Letter to the editorsA Mössbauer study on the ammonia synthetic iron catalyst Journal of Catalysis. ,vol. 14, pp. 281- 283 ,(1969) , 10.1016/0021-9517(69)90440-0
R.P Beyer, M.J Ferrante, R.R Brown, Thermodynamic properties of KAlO2 The Journal of Chemical Thermodynamics. ,vol. 12, pp. 985- 991 ,(1980) , 10.1016/0021-9614(80)90139-1
Klas Engvall, Leif Holmlid, P. Govind Menon, Comparative loss of alkali promoter by desorption from two catalysts for the dehydrogenation of ethyl benzene to styrene Applied Catalysis. ,vol. 77, pp. 235- 241 ,(1991) , 10.1016/0166-9834(91)80068-8
K. Engvall, L. Holmlid, A. Kotarba, J.B.C. Pettersson, P.G. Menon, P. Skaugset, Potassium promoter in industrial ammonia synthesis catalyst: Studies by surface ionization Applied Catalysis A: General. ,vol. 134, pp. 239- 246 ,(1996) , 10.1016/0926-860X(95)00206-5
Andrzej Kotarba, Klas Engvall, Jan B.C. Pettersson, Marcus Svanberg, Leif Holmlid, Angular resolved neutral desorption of potassium promoter from surfaces of iron catalysts Surface Science. ,vol. 342, pp. 327- 340 ,(1995) , 10.1016/0039-6028(95)00783-0
Jiaxi Wang, Klas Engvall, Leif Holmlid, Cluster KN formation by Rydberg collision complex stabilization during scattering of a K beam off zirconia surfaces Journal of Chemical Physics. ,vol. 110, pp. 1212- 1220 ,(1999) , 10.1063/1.478163