Chen Yuan, Zhao Sufang, Liu Zhigang
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China.
Phys Chem Chem Phys. 2015 Jun 7;17(21):14012-20. doi: 10.1039/c5cp01829c. Epub 2015 May 7.
A series of catalysts, i.e. metal oxides (MO) such as CeO2, Fe2O3 and Al2O3 supported Co-N-C (Co-N-C/MO) were prepared by heating supported cobalt porphyrin in a N2 atmosphere. Among the Co-N-C/MO catalysts, Co-N-C/CeO2 shows a remarkable catalytic performance for ethylbenzene oxidation with ethylbenzene conversion of 33.1% and selectivity to acetophenone of 74.8%. In addition, the interaction between Co-N-C and supports was tentatively characterized by techniques such as XRD, HRTEM, XPS etc. According to XPS, the presence of the redox cycle between Ce(3+) and Ce(4+) in CeO2 facilitates the formation of cobalt ions in the high valence state and the Co-Nx sites, which are typically responsible for the high catalytic activity. The high performance benefits from the synergistic effect between Co-N-C and CeO2 and the well-dispersed Co-based sites.
通过在氮气气氛中加热负载型钴卟啉制备了一系列催化剂，即金属氧化物（MO）负载的Co-N-C（Co-N-C/MO），如CeO₂、Fe₂O₃和Al₂O₃负载的Co-N-C。在Co-N-C/MO催化剂中，Co-N-C/CeO₂对乙苯氧化表现出显著的催化性能，乙苯转化率为33.1%，苯乙酮选择性为74.8%。此外，还通过XRD、HRTEM、XPS等技术对Co-N-C与载体之间的相互作用进行了初步表征。根据XPS，CeO₂中Ce(3+)和Ce(4+)之间的氧化还原循环促进了高价态钴离子和Co-Nₓ位点的形成，这些通常是高催化活性的原因。高性能得益于Co-N-C与CeO₂之间的协同效应以及钴基位点的良好分散。
