Self-Template Synthesis of a MnCeO_δ/Co₃O₄ Polyhedral Nanocage Catalyst for Toluene Oxidation

Herein, a novel nanocage catalyst of a porous MnCeO_δ/Co₃O₄-NC polyhedral derived from a Co-based zeolitic imidazolate framework (ZIF-67) was synthesized and its catalytic performance for toluene oxidation was evaluated. This composite of the MnCeO_δ/Co₃O₄-NC catalyst presents a high toluene conversion of 95% at 230 °C with a weight hourly space velocity of 40 000 mL g^–1 h^–1. In addition, the reaction rate based on the catalyst surface area of the MnCeO_δ/Co₃O₄-NC catalyst was 3.138 × 10^–2 mmol m^–2 h^–1. Meanwhile, the MnCeO_δ/Co₃O₄-NC catalyst also shows a lower apparent activation energy of the reaction (E_a) of 56.10 kJ mol^–1. According to the characterization results, the specific surface area, the interaction between MnCeO_δ solid solution and Co₃O₄-NC, the low-temperature reducibility, and the concentration of surface active oxygen confinement that originates from MnCeO_δ/Co₃O₄-NC proves that this catalyst has superior activity for toluene oxidation.