甲醇在催化剂MgO（100）面上吸附的量子化学研究

本文用ＣＮＤＯ／２半经验最子化学计算方法对ＣＨ３ＯＨ分子在（ＭｇＯ）４（１００）面上的２８种可能的吸附态进行了优化计算，得到以ＣＨ３ＯＨ分子中－ＣＨ３取向吸附在（ＭｇＯ）４（１００）面的Ｏ＾－原子上，且为重叠式构型最稳态。此构型中由于－ＣＨ３上的三个氢原子形成结构适应的三氢正电集团与氧的静电作用的结果。从吸附态的能量及Ｍｕｌｌｉｋｅｎ集居数上分析得甲醇在ＭｇＯ催化剂上有利于形成ＣＨ４和ＣＯ，这一结

A Quantum Chemical Study on the Adsorption of Methanol onto the Surface of Catalyst MgO(100)

The chemicsorption of CH_3OH on(MgO)_4(100)surface has been studied by semiempirical quantum chemical method (CNDO/2).According to the calculated results of 28 kinds of adsorption, the most stable orientation of the adsorbed CH_3OH is that the-CH_3 group points downward to the O atom of the MgO surface. This is the overlap configuration in the same plane.The result of the orientation is that there is the presence of a tri-hydrogen methyl group on the surface, The analyses of adsorption energy and Mulliken overlap population show that it is advantageous for the methanol to form CH_4 and CO on a MgO catalyst. This result by CNDO/2 calculation is in agreement with the experiment.