Rate Control and Reaction Engineering

A concept for evaluating the relative importance of steps in complex reactions may guide the development of better catalysts. A simple explanation for the acceleration of reactions by catalysts is that they speed up the rate-determining step. However, many reactions of practical importance are complex, multistep processes, and assessing the role that each step may play in controlling the overall rate of the reaction is not trivial.

In a recent paper, Stegelmann et al. (1) have introduced a useful concept for characterizing such reactions: the general degree of rate control. Identifying the elementary steps that exert the greatest control on the overall rate of a chemical reaction offers the possibility of finding an appropriate catalyst or improving existing ones.