Transition metal oxides have excellent catalytic activities for the oxidation of VOCs, in which it is necessary to find new catalysts/supports with cheap and environmentally-friendly properties. Herein, Co₃O₄ nanoparticles decorated eggshell catalysts were firstly synthesized via impregnation method, where the waste eggshell is used as an effective hard template and an excellent support with porous structure. A series of Co₃O₄/Eggshell catalysts were synthesized by changing the different concentration of precursors (different Co₃O₄ loadings), which were defined as Co₃O₄/Eggshell-1 (33.1 %), Co₃O₄/Eggshell-2 (16.7 %) and Co₃O₄/Eggshell-3 (9.1 %) catalysts. Among of them, the Co₃O₄/Eggshell-2 exhibited the best activity with the temperature T_{90 %} = 256 ℃, which is about 90 °C lower than Co₃O₄/oyster shell-2 (benzene catalytic oxidation). And the catalytic activity of Co₃O₄/Eggshell is remarkably improved as compared to commercially pure Co₃O₄ nanoparticles and commercially CaCO₃. The excellent activity can be attributed to the unique structure of the eggshell and the interaction of CaCO₃ and Co₃O₄. In addition, the catalyst has also showed long-term stability. Moreover, the reaction mechanism of benzene catalytic oxidation was further revealed by in-situ FTIR studies.

过渡金属氧化物对VOC的氧化具有出色的催化活性，因此有必要寻找具有廉价和环保特性的新型催化剂/载体。在此，首先通过浸渍法合成了Co ₃ O ₄纳米粒子修饰的蛋壳催化剂，该废蛋壳被用作有效的硬模板和具有多孔结构的优良载体。通过改变不同浓度的前体（Co ₃ O _4的负载量不同），合成了一系列Co ₃ O ₄ / Eggshell催化剂，定义为Co ₃ O ₄ / Eggshell-1（33.1％），Co ₃ O₄ / Eggshell-2（16.7％）和Co ₃ O ₄ / Eggshell-3（9.1％）催化剂。其中，Co ₃ O ₄ / Eggshell-2在T _90％  = 256℃时表现出最佳的活性，比Co ₃ O ₄ /牡蛎壳2（苯催化氧化）低约90°C 。并且与商业上纯的Co ₃ O ₄纳米颗粒和商业上的CaCO ₃相比，Co ₃ O ₄ / Eggshell的催化活性得到了显着提高。优异的活性可以归因于蛋壳的独特结构和CaCO ₃的相互作用和Co ₃ O ₄。另外，该催化剂还显示出长期稳定性。此外，通过原位FTIR研究进一步揭示了苯催化氧化的反应机理。