[Wonder Warthog]

"Also, in the refinery, we use heat and pressure to break down crude oil into simpler, smaller hydrocarbon molecules, not the reverse."

In the absence of a catalyst, yes. But toss in one (or several) catalysts, and the picture changes completely, which is what this article is all about. Normally forbidden or "small percentage" product scenarios then become practical.

[thackney]

I thought catalyst were used to speed up a reaction, not reverse it.

[thackney]

My understanding of catalysts is as follows:

Catalysts do not change the chemical equilibrium of a reaction. The fact that a catalyst does not change the equilibrium is a consequence of the second law of thermodynamics. If there was such a catalyst that shifted an equilibrium, the system would result in reaction to move to the new equilibrium, producing energy.

Then, removing the catalyst would also result in reaction, producing energy; i.e. the addition and its reverse process, removal, would both produce energy. Thus, a catalyst that could change the equilibrium would be a perpetual motion machine, a contradiction to the laws of thermodynamics.

Can you show me one other example where a catalyst is used to reverse the direction of a reaction?