Optimizing low-temperature CO oxidation under realistic combustion conditions: The impact of CeO₂ morphology on Au/CeO₂ catalysts

The development of carbon monoxide oxidation catalysts for complex gas environments faces significant challenges in fire scenarios. Only a few representative gases are used as interfering components in simulated real smoke under laboratory conditions, which cannot accurately reflect the performance of catalysts in a real fire. Herein, Au/CeO₂ catalysts with high activity were prepared by adjusting the morphology (rod, cube, polyhedron and irregular particles) and exposed crystal surface ratio of CeO₂. Rod-like Au/CeO₂ (Au/CeO₂-NR) achieved 99 % CO conversion at 25 °C and demonstrated excellent water resistance. This excellent activity originates from the high oxygen vacancy concentration of the CeO₂-NR and the interaction between Au species and the carrier. A testbed was established by connecting a steady-state tube furnace with a catalytic fixed-bed reactor to evaluate the CO elimination performance of the catalyst under realistic combustion conditions. Despite competitive adsorption of small molecules (H₂O, acetone, etc.) on the active sites, Au/CeO₂-NR eliminates carbon monoxide in real combustion atmospheres at only 60 °C. This study provides a method for evaluating the catalytic activity of CO in realistic environments, which is promising for practical use in application scenarios dealing with toxic fumes.