(i) CO(g)+3H2(g) →Ni(s) CH4(g)+H2O(g)(ii) CO(g)+2H2(g) →Cu/ZnO-Cr2O3 CH3OH(g)(iii) CO(g)+H2(g) →Cu HCHO(g)Which of the above reactions is/are a catalytic reaction?

CO(g)+3H2(g) →Ni CH4(g)+H2O(g)CO(g)+2H2(g) →Cu/ZnO-Cr2O3 CH3OH(g)CO(g)+H2(g) →Cu(s)HCHO(g)Here, Ni, Cu/ZnO-Cr2O3 and Cu are catalysts.Different catalysts act on same reactants give different products.