Enhancing propane oxidation with CTAB-modified ZIF-67-derived hollow Co3O4-CNTs catalysts through reduction-oxidation treatment

Co₃O₄ is an effective catalyst for propane total oxidation, and ZIF-67 pyrolysis is usually used to produce cobalt-based catalysts. However, high-temperature pyrolysis often leads to structural collapse and reduced cobalt activity. This study presents a CTAB-modified ZIF-67-derived hollow Co₃O₄-CNTs catalyst for enhanced propane total oxidation. The catalyst was synthesized through H₂/Ar reduction at 800 °C and subsequent air oxidation at 300 °C. This process preserved the cubic structure of ZIF-67 and produced abundant CNTs, which limited Co₃O₄ growth and resulted in superior catalytic activity, with a T_90 % of 230 °C-lower than that of noble metal catalysts. Increasing the oxidation temperature led to a decrease in CNTs, growth of Co₃O₄ particles, and structural collapse. The 300 °C calcined catalyst (300 A) showed the best performance due to its smallest Co₃O₄ particles and excellent reducibility, while higher temperatures led to particle agglomeration and decreased activity.