甲硫醇、甲醇在金属表面上的分解反应性能比较研究

Comparative Studies of Methanol and Methathiol Decomposition Reactivity on Metal Surfaces

用键级守恒－Ｍｏｒｓｅ势法比较了ＣＨ３ＳＨ、ＣＨ３ＯＨ在Ｎｉ（１１１）、Ｐｔ（１１１）和Ｃｕ（１１１）面上的热分解反应性能．结果表明，由Ｎｉ至Ｐｔ再至Ｃｕ，ＣＨ３ＳＨ中Ｃ—Ｓ键断裂几率降低，而Ｓ—Ｈ键裂相对几率增加，而在Ｃｕ上仅发生Ｓ—Ｈ键裂．ＣＨ３ＯＨ在Ｎｉ上易解离为ＣＨ３和ＣＨ３Ｏ—，在Ｐｔ、Ｃｕ上则较难解离．按Ｎｉ、Ｐｔ、Ｃｕ的顺序，ＣＨ３Ｓ—选择性断裂Ｃ—Ｓ键的几率增加，而ＣＨ３Ｏ—则选择性断裂Ｃ—Ｈ键的几率增加．ＣＨ３ＸＨ、ＣＨ３Ｘ—（Ｘ＝Ｏ，Ｓ）解离活化能垒依Ｎｉ、Ｐｔ、Ｃｕ的顺序增加，ＣＨ３ＯＨ在Ｎｉ上最终解离为ＣＯ，而在Ｃｕ上则解离为Ｈ２ＣＯ．

The reactivities of methanol and methathiol on Ni(111), Pt(111) and Cu(111) have been investigated using bond order conservation Morse potential(BOC MP) method. The results show that, from Ni to Pt to Cu, the relative cleavage probabilities of C S bond in methathiol decrease, and those of S H bond increase, and thus on Cu surface only the S H bond break occurs. Methanol on Ni surface is dissociated easily into CH 3 and CH 3O , but the dissociation on Pt and Cu surface is not easy. From Ni to Pt to Cu, the cleavage selectivity of C S bond in CH 3S— and C H bond in CH 3O— increases. The dissociation barriers of CH 3XH and CH 3X—(X=O, S) increase in the order Ni<Pt<Cu. The final product of CH 3OH dissociation is CO on Ni surface, and H 2CO on Cu surface.