What is meant by "an active part"? In most cases the catalyst does react chemically with one or more of the reactants to form an intermediate (possibly an adsorbed species). Subsequently, the intermediate reacts to give the desired product and the catalyst, thus regenerating the catalyst. Since the catalyst is actually participating in the reactions, I would say that it does play an active part, but it is regenerated in subsequent reactions. --Matt Stoker
Exactly. In my original definition, I said something to the effect that a catalyst participates, but is otherwise unconsumed.
I guess that was too concise for whomever decided to add the more verbose, and incorrect, text. -- dja
"net" is probably fine. I was thinking "overall" might be more precise, but I'm not sure.
Also, I've been wondering to what extent reaction mechanisms should be discussed in this entry, or in Kinetics, or . . . somewhere else? I think some of our struggles with the description of a catalyst center around the difference between the bulk view of reactions versus a molecular understanding of those reactions. In the bulk sense, they are unconsumed. In the microscopic (ie, microscopic reversability) sense, they are consumed and regenerated. This is close to, but not quite fully, a semantic distinction.
Personally, I think a simple generic reaction mechanism (as is currently in the page) is appropriate at least for the initial general discussion. More detailed discussions of reaction mechanisms would probably fit nicely in Kinetics, especially if someone could take the time to demonstrate how some important kinetic equations (eg. Eleay-Rideal and Langmuir-Hinshelwood type equations) result from elementary reactions.
One additional thought I have been pondering is whether it would be appropriate to give some examples of important industrial catalysts and catalytic processes. Would this be more appropriate under Catalyst or Catalysis, also what level of detail is appropriate?
--Matt Stoker (sorry I omitted this label initially)
In keeping with the spirit of wiki and wikipedia as I see it, as much detail as you can pump out is encouraged. Put it out there, and if necessary, it can be refactored later.
The concern I have about where to focus on reaction mechanisms is that, phenomologically, catalysis can happen, and be observed, without any reference to reaction mechanisms--you throw some stuff in, and the reaction goes faster. Understanding what a catalyst *is* doesn't *require* much of an understanding of molecularity--look at biological catalysis for examples of just how widely this is true, where the reaction mechanisms are beyond the current ken of people who've been working on the problems for ages. Even so, they can observe and quantititate the rates with/without catalyst, with just bulk stoichiometry.
Granted, if you want to understand what the catalyst is doing beyond speeding the reaction, you need to get into molecular detail, and using reaction mechanisms to model happens is key to that.
Anyway, as with open source code, he who writes the stuff determines where it goes (at least, initially).
Just my 2 cents. You're putting some great stuff in here, so don't let my quibbling get in the way of that.