Investigation of Active Center of Cu-Based Catalyst for Low Temperature Methanol Synthesis from Syngas in Liquid Phase: The Contribution of Cu+ and Cu0

LaCuMn catalyst was prepared under different reduction temperature and passivation time, and used to catalyze CO hydrogenation to methanol in liquid phase. The effect of reductive copper species on the catalytic activity and the product distribution was studied. The results showed that the surface content of reductive copper species greatly affect the catalytic activity and the approximate molar ratio of Cu+ to Cu-0 was important. The mixture of CuZn/AC-N-2 with only Cu+ and CuZn/AC-H-2 with only Cu-0 was utilized for the low temperature methanol synthesis from syngas in liquid phase. It was confirmed that both of the reductive copper species of Cu+ and Cu-0 were active species and Cu+ was superior to Cu-0. Moreover, the synergic function of Cu+ and Cu-0 led to the enhancement of the catalytic activity of Cu based catalyst, and the optimum molar ratio of surface Cu+ to Cu-0 was in the range of 3.5 to 4.0.