On the Theory of Gas Reactions.

(Heinrich Löwy, Ann. d. Phys. 1915, p. 561).

A comparatively very long time ago, Liebig expressed the idea that in catalytic reactions, apparently, a role is played by resonance between the molecular vibrations of the catalyst and of the substance participating in the reaction; or, translating this idea into the language of electrodynamics, one may say that catalytic reactions are something very similar to a kind of internal photoelectric process. The idea is very remarkable, and from the point of view of the modern theory of the solid body, where electromagnetic processes are assigned an exceptional role, it appears highly plausible. Löwy’s work sets itself the task of tracing, in gas catalytic reactions, the fruitfulness of the idea expressed. First of all, Löwy shows that although the experimental and theoretical material of recent years speaks against a direct Liebig resonance, nevertheless an interaction between the electromagnetic vibrations of the gas molecules and the catalyst molecules is very probable, in view of the fact that gas catalytic reactions proceed in an adsorbed layer of relatively high concentration, where the region of natural frequencies within which the system of oscillators attains its maximum is different from that in the unadsorbed gas.

Next Löwy considers an ordinary gas reaction proceeding according to the scheme:

\[ (A) + (B) \rightleftarrows (AB). \]

And, assuming that the numbers of decomposing molecules are proportional to the vibrational energy \(E\), which, in turn, is of a quantum character, he obtains the following expression for the mean vibrational energy necessary for the decomposition of the molecule \((AB)\):

\[ \epsilon = \frac{\sum (nh\nu)^2 e^{-\frac{nh\nu}{kT}}} {\sum (nh\nu) e^{-\frac{nh\nu}{kT}}} \]

\(n = 1, 2, 3\), etc.