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A series of 3.0Mo/(Hβ+γ-Al_2O_3) samples with γ-Al_2O_3 contents in the range of 0_100%(mass fraction) was studied by means of XRD, NH_3-TPD, TPR and BET determinations for characterizing their structures. The Hβ zeolite structure in the 3.0Mo/Hβ sample can be effectively stabilized by adding some γ-Al_2O_3 to Hβ zeolite. γ-Al_2O_3 mainly favors the formation of polymolybdate or multilayered Mo oxide, while Hβ mainly forms the Al_2(MoO_4)_3 species, as evaluated by the TPR technique. When used as the catalyst for the metathesis of butylene-2 and ethylene to propylene, there exists a close correlation between the specific surface area and stability of the catalyst. The specific surface area of the catalyst shows the maximum when {(Hβ+}γ-Al_2O_3) contains 30%γ-Al_2O_3, which is in agreement with that of the time needed for the reaction stablization. In the case of maximum surface area, the rate of coke deposition is the minimum.
A series of 3.0 Mo / (Hβ + γ-Al 2 O 3) samples with γ-Al 2 O 3 content in the range of 0-100% mass fraction was studied by means of XRD, NH 3- TPD, TPR and BET determinations for characterizing their structures. Hβ zeolite structure in the 3.0Mo / Hβ sample can be effectively stabilized by adding some γ-Al_2O_3 to Hβ zeolite. Γ-Al_2O_3 mainly favors the formation of polymolybdate or multilayered Mo oxide, while Hβ mainly forms the Al_2 (MoO_4) _3 species, as evaluated by the TPR technique. When used as the catalyst for the metathesis of butylene-2 and ethylene to propylene, there exists a close correlation between the specific surface area and stability of the catalyst. The specific surface area of the catalyst shows the maximum when {(Hβ +} γ-Al 2 O 3) contains 30% γ-Al 2 O 3, which is in agreement with that of the time needed for the reaction stablization. In the case of maximum surface area, the rate of coke deposition is the minimum.