Abstract:

Oxygenated volatile organic compounds (OVOCs) exemplified by butyl acetate, which posed severe environmental and health risks due to their low odor threshold, substantial industrial emissions, and detrimental ecological effects. The efficient abatement of OVOCs was not only imperative for air quality improvement but also aligned with the core principles of green chemistry by minimizing the release of hazardous volatiles and reducing energy consumption. There was an urgent need to develop highly efficient catalytic technologies to mitigate the persistent threat these compounds present to atmospheric environments and public health. In this study, cerium (Ce)-based monolithic catalysts synthesized by in situ growth method were developed for practical catalytic applications and demonstrated enhanced active species loading capacity. The introduction of Ce leveraged the inherent high oxygen storage capacity of CeO₂ to enhance reactant activation and oxidation. Meanwhile, Ce species activate the alloy on the metallic foam support, facilitating electron transfer and promoting redox cycles between Ce⁴⁺/Ce³⁺, Co³⁺/Co²⁺, and Ni²⁺/Ni³⁺. This process concurrently induced additional oxygen vacancies formation. Thus, the Ce/Co-Ni foam catalyst exhibited exceptional removal efficiency exceeding 99% at 230 °C. Furthermore, it maintained removal performance above 80% under challenging conditions, including prolonged operation and the presence of 8 vol% H₂O. This study revealed that the foam substrate within the monolithic catalyst served not only as structural support but also functioned as an active component, significantly influencing the overall catalytic activity. These findings provided a novel strategy for designing high-performance monolithic foam catalysts.

Key words: Oxygenated volatile organic compounds, Monolithic catalyst, CeO₂ species, Electron transfer, Oxygen vacancy