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用分子动力学(MD)方法模拟研究了300K下乙烯在正交MFI、单斜MFI以及H[Al]ZSM-5中的吸附、极化和扩散行为.结果表明,乙烯与正交MFI的作用最强;在正交MFI中乙烯具有相对较低的总能量.在H[Al]ZSM-5中铝和B酸质子的存在有利于降低乙烯分子的能量.在孔道交叉部位的边界处特别是铝址附近,乙烯分子受极化较大、偶极矩增高.乙烯分子出现在孔道交叉部位的几率最大.在上述3种晶系中乙烯的扩散系数分别为2.7,2.1和1.6×10~(-9)m~· s~(-1).乙烯在H[Al]ZSM-5中的红外光谱呈现(v_(10),v_7,v_(12),v_(11)和v_9)5个吸收峰,与实验相吻合.
The adsorption, polarization and diffusion behaviors of ethylene at 300K in orthogonal MFI, monoclinic MFI and H [Al] ZSM-5 were studied by molecular dynamics (MD) method. The results showed that the effect of ethylene on orthogonal MFI The strongest; ethylene has a relatively lower total energy in the orthogonal MFI The presence of aluminum and B proton in H [Al] ZSM-5 favors the reduction of the energy of the ethylene molecules At the boundaries of the crossings of the channels are, in particular, In the vicinity of the aluminum site, ethylene molecules are more polarized and their dipole moment is higher, and the ethylene molecules have the highest probability of crossings in the channels. The diffusion coefficients of ethylene in the three crystal systems are 2.7, 2.1 and 1.6 × 10 ~ -9) m s -1 .The IR spectra of ethylene in H [Al] ZSM-5 showed five absorptions (v_ (10), v_7, v_ (12), v_ (11) and v_9) Peak, consistent with the experiment.