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用多晶X射线衍射法测定了经加压交换镍后的ZSM-5分子筛的结构,发现Ni~(2+)在ZSM-5骨架外有两种位置。Ni~(2+)(1)位于面向两个通道交叉处的空腔的六元环中心线的中点附近,偏离通道壁约1.5(?)。它不在通道中,但它可直接影响ZSM-5活性中心附近的电荷分布,从而影响ZSM-5的催化性能。Ni~(2+)(2)位于平行于[100]方向的“Z”字形通道中,偏离十元环中心约1.6(?)。Na~(2+0(2)的存在改变了“Z”字形通道开口的有效空隙,同时Ni~(2+)(2)本身也可能与进入分子筛通道的反应物接触,参与催化作用。
The structure of ZSM-5 molecular sieve after pressure-exchanged nickel was determined by polycrystalline X-ray diffraction. It was found that Ni 2+ has two positions outside the ZSM-5 skeleton. Ni ~ (2 +) (1) is located near the midpoint of the six-membered ring centerline of the cavity facing the intersection of the two channels, offset by about 1.5 (?) From the channel wall. It is not in the channel, but it can directly affect the ZSM-5 near the center of the charge distribution, thus affecting the catalytic performance of ZSM-5. The Ni 2 + 2 located in the zigzag path parallel to the [100] direction and deviated from the center of the ten-ring about 1.6 (?). The presence of Na ~ (2 + 0 (2) changes the effective gap of the opening of the “Z” shaped channel, and the Ni ~ (2 +) (2) itself may also come into contact with the reactants entering the molecular sieve channel to participate in the catalysis.