TY - JOUR
T1 - Dehydrogenation of ethylbenzene over highly active and stable perovskite oxide catalyst - Effect of lattice oxygen on/in perovskite oxide and role of A/B site in perovskite oxide
AU - Watanabe, Ryo
AU - Sekine, Yasushi
AU - Kojima, Jungo
AU - Matsukata, Masahiko
AU - Kikuchi, Eiichi
PY - 2011/5/15
Y1 - 2011/5/15
N2 - Previously we reported that La0.8Ba0.2Fe 0.4Mn0.6O3-δ (LBFMO) perovskite oxide catalyst showed extremely high activity for dehydrogenation of ethylbenzene to produce styrene. The reaction mechanism of dehydrogenation of ethylbenzene over LBFMO catalyst and the role of A/B site cation in the perovskite were investigated using transient response experiments and thermogravimetric analyses in a H2O/H2 atmosphere. Results showed that the dehydrogenation of ethylbenzene over LBFMO perovskite catalyst proceeded via reduction-oxidation (redox) of the perovskite oxide in this temperature range (800-900 K). Thereby, oxidative dehydrogenation of ethylbenzene consumed lattice oxygen in the perovskite; the consumed lattice oxygen was regenerated by H 2O. We measured the lattice oxygen release rate and regenerating rate over LBFMO perovskite catalyst. The regeneration rate of lattice oxygen was almost equal to the formation rate of styrene in the steady state of the dehydrogenation reaction. Substituting the B site of perovskite with Fe has a stabilizing effect for the lattice oxygen in the perovskite, and enhanced the regeneration rate of lattice vacancy drastically using steam. We concluded that the better stability of LBFMO than that of other catalysts was derived from enhanced lattice oxygen regeneration in the perovskite.
AB - Previously we reported that La0.8Ba0.2Fe 0.4Mn0.6O3-δ (LBFMO) perovskite oxide catalyst showed extremely high activity for dehydrogenation of ethylbenzene to produce styrene. The reaction mechanism of dehydrogenation of ethylbenzene over LBFMO catalyst and the role of A/B site cation in the perovskite were investigated using transient response experiments and thermogravimetric analyses in a H2O/H2 atmosphere. Results showed that the dehydrogenation of ethylbenzene over LBFMO perovskite catalyst proceeded via reduction-oxidation (redox) of the perovskite oxide in this temperature range (800-900 K). Thereby, oxidative dehydrogenation of ethylbenzene consumed lattice oxygen in the perovskite; the consumed lattice oxygen was regenerated by H 2O. We measured the lattice oxygen release rate and regenerating rate over LBFMO perovskite catalyst. The regeneration rate of lattice oxygen was almost equal to the formation rate of styrene in the steady state of the dehydrogenation reaction. Substituting the B site of perovskite with Fe has a stabilizing effect for the lattice oxygen in the perovskite, and enhanced the regeneration rate of lattice vacancy drastically using steam. We concluded that the better stability of LBFMO than that of other catalysts was derived from enhanced lattice oxygen regeneration in the perovskite.
KW - Dehydrogenation of ethylbenzene
KW - Lattice oxygen
KW - Perovskite oxides
KW - Redox properties
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U2 - 10.1016/j.apcata.2011.03.016
DO - 10.1016/j.apcata.2011.03.016
M3 - Article
AN - SCOPUS:79955476577
SN - 0926-860X
VL - 398
SP - 66
EP - 72
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
IS - 1-2
ER -