Fe-modulated Cu–ZnO–CeO2 catalysts for methanol synthesis from CO2 hydrogenation

Fe-modulated Cu-ZnO CeO 2 catalysts were synthesized via sol-gel method. • Moderate Fe doping suppressed CuO growth and improved Cu dispersion. • Fe tuned the interface and oxygen defects to balance reducibility. • Fe10-CZCe achieved 14.5% CO 2 conversion with high methanol selectivity. • The promotion by Fe stems from interfacial regulation, not new phases. Copper-based catalysts have been widely applied in methanol synthesis from CO 2 hydrogenation. Yet efficient operation at an industrially relevant level remains challenging. The use of CO 2 as a carbon source is still limited by difficult molecular activation and by imperfect interfacial matching. Here, a series of Fe-doped Cu-ZnO CeO 2 catalysts was prepared by a sol-gel route. The influence of Fe content on phase structure, surface electronic environment, reduction behaviour, CO 2 adsorption characteristics and catalytic performance was examined systematically. Fe incorporation did not change the fundamental phase composition of CuO and CeO 2 . It did, however, strongly affect Cu dispersion, the near-surface defect environment of CeO 2 , and the electronic structure of the interface. Moderate Fe addition suppressed CuO crystallite growth, improved Cu dispersion, and produced a more concentrated reduction profile with a more suitable distribution of CO 2 adsorption strength. Excess Fe enhanced defect-related signals and high-temperature adsorption, but also increased interfacial perturbation, which was unfavourable for the further conversion of intermediates. At 3 MPa and 260 °C, Fe10-CZCe showed the best overall performance, giving a CO 2 conversion of 14.5% together with high methanol selectivity and the highest methanol space-time yield. The beneficial role of Fe is therefore linked to reconstruction of the Cu-ZnO CeO 2 interface, which promotes a more effective balance between CO 2 adsorption, activation and hydrogenation. These findings provide a useful perspective for compositional tuning and interface design in Cu-based catalysts. Download: Download high-res image (231KB) Download: Download full-size image