No catalyst can catalyze water into oil because catalysts can only catalyze reactions that can actually occur, and they cannot help with reactions that cannot occur in the first place. For example, the ammonia reaction and the oxidation of sulfur dioxide are reactions that can actually occur, but in general these reactions proceed more slowly, so they need the help of a catalyst.

At present, the role of the catalyst is not fully understood. In most cases, it is believed that the catalyst itself participates in the chemical reaction along with the reactants, reducing the activation energy required for the reaction. Some catalytic reactions are due to the formation of easily decomposable "intermediates", when the decomposition of the catalyst restores the original chemical composition, the original reactants become products.