“…Li et al synthesized catalysts via isomorphous substitution of zinc malachite by Al 3+ ions, and attributed the improved methanol synthesis rate to enhanced Cu−ZnO synergy induced by oxygen vacancies. 17 Nevertheless, the Cu−ZnO synergy may also stem from Cu−Zn alloy, 18,19 Cu−ZnO interfaces, 20,21 induced strain of Cu NPs, 22,23 or hydrogen spillover model; 24 In the present study, in order to exclude the potential structural effect of aluminum, a series of aluminum doped catalysts were synthesized via a facile two-step coprecipitation method. Then the physicochemical properties of catalysts were investigated by a series of characterizations including X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen physisorption, X-ray photoelectron spectroscopy (XPS), H 2 -Temperature-programed reduction (H 2 -TPR), Transmission electron microscope (TEM), CO 2 -temperatureprogramed desorption (CO 2 -TPD) and CO 2 −N 2 O titration.…”