合成气(CO+H_2)在Ni,Cu及Ni-Cu合金上甲烷化反应的键级守恒法能学研究

An Energetics Study on Syngas (CO + H_2) Methanation Reaction on Ni, Cu and Ni - Cu Alloy Surfaces by Bond - order Conservation Model

将键级守恒-Morse势方法应用于合金体系,作了部分修正.通过与Ni(100),Cu(100)比较,研究了NiCu(100)上合成气甲烷化反应活性.表明,因Cu的加入,NiCu上甲烷化反应活性较Ni上显著降低,并通过CO在Ni上解离形成的积碳现象给予了解释.此外,还考察了甲烷化反应的速控步骤,及因解离物种可能在表面上的沉积使表面有所改性,从而影响CO甲烷化表面反应的活性.

Bond - order conservation - Morse potential method has been some modified for alloy systems. Comparison with Ni(100) and Cu(100), syngas (CO + H2) methanation activity on NiCu(100) has been studied. The results show, due to the introduction of Cu, methanation on NiCu has much lower activity than on Ni, which can be explained by the formation of deposited Csfrom CO dissociation on Ni surfaces. Also, we investigate the rate - determining - step of methanation reaction on those surfaces, and the influences of the deposited surface species at reaction beginning on the reactivity of CO methanation.