We aimed at elevating catalytic performances of cobalt tetrakis(pentafluorophenyl)porphyrin (Co TPFPP) through axial coordination, nanocavities, and covalently grafting action. The Co TPFPP was immobilized onto nanoporous and nonporous chitosan, forming Co TPFPP/np‐ and nonp‐CTS catalysts, respectively. The catalysts were characterized by various spectroscopic techniques. The catalytic performances of these catalysts for cyclohexane oxidation under response‐surface‐methodology‐optimized oxidation reaction conditions were estimated and compared. Co TPFPP/np‐CTS was an excellent catalyst at aspect of catalytic activity, exhibiting the considerable potential reusability, 24.2 mol % yields (KA oil : cyclohexanone and cyclohexanol) in average, and total turnover frequencies (TOFs) of 3.25×106 h−1. This is attributed to the structural characteristics of the Co TPFPP/np‐CTS catalyst: the cobalt porphyrin molecules could be highly scattered on CTS, forming the independent active sites, and were not leached. The axial coordination exerted the most important effect on the catalytic activity, and the covalent grafting action had a decisive effect on the increase of the total TOFs and on the reusability of the catalyst.
Zinc sulfide-supported iron tetrakis (4-carboxyl phenyl) porphyrin (Fe TCPP/ZnS) was prepared and used for aerobic cyclohexane oxidation. X-ray diffraction, ultraviolet-visible spectroscopy and Fourier-transform infrared spectroscopy were carried out. The effects of oxygen pressure, reaction temperature, amount of iron tetrakis (4-carboxyl phenyl) porphyrin (Fe TCPP) and reaction time on the Fe TCPP/ZnS-catalyzed cyclohexane oxidation process were investigated. Fe TCPP/ZnS exhibited excellent activity for aerobic cyclohexane oxidation. Under optimal reaction conditions, the turnover number, cyclohexane conversion, cyclohexanone and cyclohexanol yields were 8.6 × 105, 64.9% and 24.4%, respectively. The stability of Fe TCPP was improved after immobilization on zinc sulfide (ZnS), and the catalyst maintained nearly original levels of activity after several reaction cycles.