Synergistic CuZnAlZr Catalyst Enabling Efficient Coconversion of CO/CO ₂ to Methanol

Direct methanol synthesis from CO 2 -rich syngas provides an effective route to eliminate the need for CO 2 separation units in industrial applications. However, achieving efficient CO/CO 2 coconversion remains a considerable challenge due to the distinct activation behaviors of the respective C–O bonds. Herein, a series of CuZnAlZr catalysts were prepared by tailoring Cu 0 particle size and Cu–ZnO interaction applied for CO/CO 2 cohydrogenation to methanol from CO 2 -rich syngas. The optimal catalyst achieved 100% methanol selectivity with a stable methanol space-time yield of 558 g/(kg cat ·h) at CO and CO 2 conversion of 70% and 20%, respectively. (H 2 /CO/CO 2 )-TPD results revealed that the synergy between moderate Cu 0 particle size and strong Cu-ZnO interaction created an “H-rich/C-lean” microenvironment, which promoted the CO/CO 2 cohydrogenation to methanol. In situ DRIFTS and atmosphere switching experiments indicated that the H 2 /CO/CO 2 mixture promoted the formation of methoxy species and confirmed that CO 2 served as the primary carbon source. Furthermore, DFT calculation and CO-TPSR-WGS-MS characterization confirmed that the strong Cu–ZnO interaction promoted the water–gas shift activity, which in turn led to higher CO conversion. This work provides insights for efficient catalyst design and is a promising candidate for industrial application.