Implications of Collision Induced Activation, Desorption and Absorption

The impact of the observations of collision induced chemistry, desorption and absorption for understanding surface chemistry in a high pressure environment is potentially large because, in a high pressure environment, an adsorbate-covered catalyst is continually bombarded by a large flux of high energy molecules. Therefore, having shown that collision induced processes occur, we believe that no mechanism for surface reactions under high pressure conditions can now be considered complete without an assessment of the importance of collision induced processes as a major reaction step. In fact, there are many unexplained observations in the literature of effects of inert gases on the rates of high pressure, heterogeneous catalytic reactions. It is now important to reinvestigate these catalytic reactions in light of the knowledge that these collision induced processes can and do occur. Collision induced chemistry and desorption are additional plausible reasons why surface chemistry at high pressures is often very different from the chemistry in UHV environments.