| 摘要 |
The invention provides a modified adsorbent material impregnated with a metal oxide, which can be used in a filter element adapted for use in a smoking article. The modified adsorbent material exhibits increased filtration efficiency with respect to certain gas phase species of mainstream cigarette smoke. Exemplary adsorbent materials that can be modified according to the invention include activated carbon, molecular sieves, clays, ion exchange resins, activated aluminas, silica gels, meerschaum, and mixtures thereof. One example of a metal oxide is cerium oxide. Impregnation with a metal oxide can be accomplished by directly treating the adsorbent with a metal oxide or impregnating the adsorbent with a metal oxide precursor, such as cerium nitrate, followed by calcining the impregnated material to convert the precursor to the desired metal oxide. Methods of forming the modified adsorbent material and smoking article filters incorporating the modified adsorbent material are also provided.
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