Alcohol-assisted low temperature methanol synthesis from syngas was conducted in a batch type reactor using ethanol as both a solvent and a reaction intermediate. Cu/ZnO.X catalysts were prepared by a co-precipitation method with different co-precipitation pH values (x= 6-10), with an aim of investigating the effect of pH value on the catalytic activity of Cu/ZnO_X catalysts in this reaction. The co-precipitation pH value had a strong influence on the Cu crystallite size, the surface morphology, and the surface acidity, leading to the different activities of Cu/ZnO_X catalysts depending on the pH value (X). Catalyst characterization and reaction mechanism clearly revealed that Cu crystallite size and strong acidity of Cu/ZnO_X catalysts played key roles in determining their catalytic activity in this reaction. Yield for methanol showed a tendency to increase with decreasing Cu crystallite size and with increasing strong acidity of Cu/ZnO_X catalysts. Among Cu/ZnO_X catalysts, Cu/ZnO_8 catalyst prepared at pH 8 showed the best catalytic performance due to the finely dispersed Cu particles and the high strong acidity. In addition, the catalytic activity of Cu/ZnO_8 catalyst maintained at the same level even after a 60 h-catalytic reaction, leading to the high feasibility of application of Cu/ZnO_8 catalyst to the continuous reaction system along with the batch reaction system for methanol production from syngas. (C) 2015 Elsevier B.V. All rights reserved.