What happens when hydrogen is added to copper oxide?

Two instances of copper oxide reaction with hydrogen in real life applications are noteworthy. Both of these hydrogen reaction scenarios with copper oxide occur at elevated quickly at temperatures, 425 C. and above, although reduction is reported as low as 170C. (1). read more

When the copper oxide is on the surface of the metal (as in scale), the hydrogen reduces the copper oxide(s) to copper metal (Cu), the hydrogen forming H2O with reduction of the copper oxide. read more

Copper oxide gets reduced to copper and water is formed due to high reactivity of hydrogen gas which results in a displacement reaction in which hydrogen displaces copper from its oxide and forms water, the reaction which you have mentioned is used for large scale extraction of copper from its ore or a compound tenorite . read more