TY - JOUR
T1 - Decomposition of chlorofluorocarbons over metal phosphate catalysts III. Reaction path of CCl2F2 decomposition over AlPO4
AU - Takita, Yusaku
AU - Wakamatsu, Hironori
AU - Tokumaru, Masami
AU - Nishiguchi, Hiroyasu
AU - Ito, Masami
AU - Ishihara, Tatsumi
PY - 2000/3/13
Y1 - 2000/3/13
N2 - Decomposition of CCl4, CCl2F2, CClF3, and CF4 was studied in the presence of water vapor over AlPO4. They began to decompose at about 300, 330, 450, and 550°C, respectively. A good linear relationship between the reactivity of CFCs and the bond dissociation energy of the C-Cl bond suggests that the C-Cl bond cleavage is the rate-determining step. The lattice structure of AlPO4 before reaction was slightly distorted but the environment of Al and P ions became uniform after the reaction, consistent with a slight progress of crystallization of AlPO4. Supporting AlPO4 onto active charcoal is not preferable to the support because of its reactivity to water vapor. ALPO-5 was less active than that AlPO4 because the inside of the pores of ALPO-5 is hydrophobic and not effective for the CCl2F2 decomposition. Meso-porous AlPO4 showed almost the same activity with AlPO4, but the destruction of the meso-porous structure brought about a loss of activity at 400°C.
AB - Decomposition of CCl4, CCl2F2, CClF3, and CF4 was studied in the presence of water vapor over AlPO4. They began to decompose at about 300, 330, 450, and 550°C, respectively. A good linear relationship between the reactivity of CFCs and the bond dissociation energy of the C-Cl bond suggests that the C-Cl bond cleavage is the rate-determining step. The lattice structure of AlPO4 before reaction was slightly distorted but the environment of Al and P ions became uniform after the reaction, consistent with a slight progress of crystallization of AlPO4. Supporting AlPO4 onto active charcoal is not preferable to the support because of its reactivity to water vapor. ALPO-5 was less active than that AlPO4 because the inside of the pores of ALPO-5 is hydrophobic and not effective for the CCl2F2 decomposition. Meso-porous AlPO4 showed almost the same activity with AlPO4, but the destruction of the meso-porous structure brought about a loss of activity at 400°C.
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U2 - 10.1016/S0926-860X(99)00353-1
DO - 10.1016/S0926-860X(99)00353-1
M3 - Article
AN - SCOPUS:0033687432
VL - 194
SP - 55
EP - 61
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
SN - 0926-860X
ER -