Basic BOC-MP Applications

Conceptually, the most important model conclusion is that for a diatomic AB, the heat of molecular chemisorption QAB relates to both the heats of chemisorption of coordinated atoms QA and QB and the A—B bond energy 

Experimental Heats of Atomic Chemisorption QA on Some Metal Surfaces  

Within the BOC-MP framework, the values of Qh (QB) and DAB are not calculated, but are taken from experiment, which forms the thermodynamic basis of the BOC-MP model. So before considering the model projections on 2AB, lei us summarize the necessary background concerning Qa (Qb). 

Now we are ready to calculate QAB for a variety of molecules AB chemisorbed in different coordination modes. We begin with weakly bound diatomic and polyatomic molecules for which the values of QAB do not depend on bond energy partitioning, and, therefore, the validity of Eqs. (10a) and (11) can be tested directly. 

For the Vl-C monocoordination M -AB via A, Eq. (10a) formally projects that QAB n will increase as n increases. However, because Eqs. (9) and (10a) were simplified by neglecting the negative terms, also increasing in absolute value with n (18d), we expect the effective compensation resulting in the weak dependence of gAB on n, the dependence being the weaker the larger is the value of DAB. 

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