Review of the heats of chemisorption of gases at metals in the context of the problem of ‘Heterogeneous’ vs. ‘Homogeneous’ catalytic surfaces

摘要

A critical review of available data on the heats of chemisorption of gases at metals is given. The effect of upward technical and procedural trends on measured results is demonstrated. The results for surfaces approached to their states occurring in catalytic processes are accentuated. Several tens of chemisorbent/gas systems are considered; a number of the results are confirmed by several independent measurements. The coverage-independence of heats of chemisorption for powders, supported catalysts, components of multi-component catalysts, and films is demonstrated; the better the techniques and procedures, the closer to zero the angle between the heat-coverage function and the abscissa. The principal conclusion on surface homogeneity of stabilized surfaces is made.