Ammonia oxidation in a microreactor

How do you add the catalyst?

Way back a few pages ago, we talked about catalysts and how they speed up reactions. The ammonia oxidation reaction uses of a heterogeneous rhodium-platinum catalyst. Citing our trusty reference (WBM2000) again, heterogeneous means different in kind; not at all similar; unlike; varied. In the world of catalysts, this means the catalyst is different from the reactants and products. For the ammonium oxidation reaction, the catalyst is a solid while the reactants and products are all gases. The other part of the catalyst's name - rhodium-platinum - refers to the metals that are used to make up the catalyst. Catalysts are usually very expensive. A few grams of the ammonia oxidation catalyst would probably buy that _____ (insert the name of an expensive must-have item) you've always wanted.

How this catalyst is 'charged' to a microreactor is definitely important in terms of how well the reactor performs. A process called anodic oxidation is used to roughen up the walls and then the catalyst is added.

BUT ...

If you're really interested, check out the junior chemical engineer's version of this page.

If you're sort of lost, here's how to get all the way back to the beginning of the high school version