Mechanistic Background of the Carbide-Based Mechanism

The initiation of the reaction proceeds through dissociative adsorption of CO. The fate of the species produced upon hydrogenation or strong hydrogen 

As we will describe below, the case gives the polymerization model 

We will discuss here some of the mechanistic questions that relate to the three different reaction regimes  

We will comment in the discussion section on the feasibility to deduce rate ratios from the order of reaction in H2 or CO in kinetics expressions, or by comparison of rates in which H2 is replaced by D2. Interpretation of such experiments requires assumptions on rate-controUing steps. As indicated above, these are different for methanation and FT kinetics. In the FT reaction, hydrogenation of carbonaceous reaction intermediates is slow and will hence dominate H2/D2 exchange differences in kinetics. 

It has to be noted that hydrogen-activated CO dissociation through intermediate COH leads to C g and On dense surfaces, this provides an overall reaction 

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