Heterogeneous catalysis reconstruction model

The computational studies on surface chemistry of Co catalysts have offered significant supports to the investigation of FTS on Co catalysts. However, the work is far from decent. As the experimental studies indicated, surface reconstruction and phase transition were certain to take place under practical FTS conditions. The theoretical studies about surface reconstruction and phase transition of Co catalysts, however, are fairly rare. In addition, cluster models were less studied in the previous theoretical work compared to slab models. However, practical catalytic reactions do not always happen as proposed in ideal plane models, nor the active sites distribute homogeneously on the surface. The investigation on cluster models is acting a crucial role in the study of heterogeneous catalysis. Accordingly, more considerations on surface reconstruction, phase transition, and cluster models should be taken into account in future work. 

Since the forces responsible for multilayer adsorption have the same nature as, and are of comparable intensity with, the ones which stabilize the condensed phase, multilayer adsorption can be viewed as a kind of adsorption on reconstructable surfaces. This conclusion became clear to the author immediately after he presented the model of section 3.2 to the 2nd Symposium on the Effects of Surface Heterogeneity in Adsorption and Catalysis on Solids [73] transforming this idea in a theory, however, was not easy. This goal was achieved only two years later by Cerofolini and Meda, who proposed a clustering and melting (C M) theory of multilayer adsorption [74]. The essentials of the C M theory are sketched in the following. 

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