How does this work exactly? Does it need some sort of kick in order to come together, or does it come together when put in a pressurized chamber?
1 Answer
I believe you are referring to the Sabatier process. $$\ce{CO2 + 4H2 -> CH4 + 2H2O}$$
The reaction uses a $\ce{Ni}$ catalyst and is done at $300-400\,^{\circ}{\rm C}$ and high pressures. The reaction is exothermic, $\Delta H = −165.0~\mathrm{kJ\,mol}^{-1}$, but requires initial heating in order to start the reaction off due to the activation energy.