Enhancing stability of industrial Cu-based catalysts under harsh reduction reaction conditions with silica armor protection

Cu-based catalysts are widely employed in various industrial processes, yet they are susceptible to deactivation due to sintering. Inhibiting the sintering deactivation of Cu nanoparticles has been a long-standing challenge for Cu-based catalysts. In this study, we propose a novel silica armor strategy to effectively protect Cu-based catalysts from sintering. Bioethanol dehydrogenation was selected as the test reaction, with the resulting products of acetaldehyde and hydrogen displaying strong reducing properties. After a 160-hour reaction period, the Cu nanoparticles in Cu/ZnO protected by a silica armor demonstrated exceptional stability, as the sintering of the Cu nanoparticles was effectively prevented. High resolution transmission electron microscope (HRTEM), X-ray absorption (XAS), and theoretical calculations were carried out to disclose the reasons for the stabilization of Cu nanoparticles by silica armor. The physical confinement created by the silica armor and the interactions between silicon species and Cu species efficiently suppressed the sintering of Cu particles. Furthermore, our research has showcased the potential application of the silica armor strategy on commercially available catalysts, highlighting its ability to effectively prevent the sintering of Cu particles on high-Cu content Cu/ZnO/Al2O3 industrial catalysts.