Full use of factors promoting catalytic performance of chitosan supported manganese porphyrin

Abstract

in order to make full use of the impact of internal and external factors on the performance of title catalyst for ethyl benzene oxidation, the key internal influencing factors on the catalytic performance were modulated by coordinating and grafting manganese porphyrin to mesoporous and macroporous chitosan, and the important external factors (i.e. oxidation reaction conditions) were optimized using Response Surface Methodology. Under the Response Surface Methodology optimized oxidation reaction conditions (176.56 °C, 0.59 MPa, and 0.25 mg amount of manganese porphyrin), the catalyst could be used at least five times. The ethyl benzene conversion, catalyst turnover numbers, and yields reached up to 51.2%, 4.37 × 10 6 and 36.4% in average, respectively. Compared with the other optimized oxidation reaction conditions, the corresponding values increased 17%, 26% and 53%. Relative to the manganese porphyrin, the catalytic performance and efficiency of the immobilized catalyst had notably increased. High-efficiency and high-selectivity oxidation of ethyl benzene (EB) has been still paid a great attention 1-6. There were so many advanced catalysts and catalytic ethyl benzene oxidation technologies 1-25 , some of which could even offer high yields of products 1-6. However, up to date the oxidation techniques used are not very satisfactory yet: There were mainly lack of cleaner production techniques, for examples, O 2 was not used as oxidant, toxic solvents were used, some energy saving and emission reduction had not been done, and so on. Therefore, the catalyst preparation 21-25 , the catalytic oxidation system and the oxidation conditions 7-20 , which are satisfactorily meeting to the cleaner production process should be comprehensively considered. Based on the above considerations, the internal influencing factors on the catalytic performance of catalyst should be further reasonably tuned, and the external influencing factors should be optimized via Response Surface Methodology (RSM). Because RSM has been successfully used in other catalysis fields: It has been used for optimization of the various reaction conditions and prediction of interactions between the influencing reaction condition parameters based on constructing a suitable model, evaluating the effects of key factors and searching the optimum reaction conditions. The better catalysis responses have achieved 26-29. These considerations and the various optimizations above will probably bring the advanced catalysis techniques 7-25 forwards better catalytic results and excellent various applications in practical chemistry industry. Due to a great deal of attention to the environmental issues, for modern companies which are manufacturing the products of acetophenone and phenylethanol via ethyl benzene oxidation, a set of strict modern technique of cleaner production has to be requested. Under the preconditions, the immobilized metalloporphyrins and their catalysis systems, which are usually not added any additives, co-reductants, and solvents, but oxygen molecules...

V-Porphyrins Encapsulated or Supported on Siliceous Materials: Synthesis, Characterization, and Photoelectrochemical Properties

“…Due to their stable macrocyclic structure, porphyrins constitute an exceptional class of ligands with tailorable chemical properties, which is of high interest in the development of selective homogeneous or heterogeneous catalysts and photocatalysts [ 1 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. In fact, porphyrin and metalloporphyrin complexes have been used pure [ 6 , 7 , 8 , 9 ], supported on several materials [ 10 , 11 , 12 , 13 ], immobilized on silica or mesoporous materials [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], or incorporated into MOFs [ 21 , 22 , 23 ], presenting a high ability to catalyze a variety of reactions such as oxidations, epoxidations, hydrogenation, or deoxygenation.…”

“…Vanadium(IV)-porphyrin-containing materials are also paramount [ 24 , 25 , 26 , 27 ], in which special attention has been paid to the use of Vanadyl-porphyrins incorporated on the surface of supports or encapsulated in mesoporous materials [ 13 , 28 , 29 , 30 , 31 , 32 ]. It is well-known that changes in the type of functional groups and/or in the position of the substituents in the porphyrin macrocycle can give rise to modifications in the physicochemical and catalytic properties [ 6 , 7 , 8 , 9 ], but significant changes in physicochemical characteristics could also occur when incorporating metalloporphyrins into inorganic oxides [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 28 , 29 , 30 , 31 , 32 ]. The role of vanadium is important in these applications.…”

DMAP and HMTA manganese(III) meso-tetraphenylporphyrin-based coordination complexes: Syntheses, physicochemical properties, structural and biological activities

“…More recently, in 2020, it has been reported by Mo et al [17], the use of coordinated and grafted manganese porphyrin to mesoporous and macroporous chitosan as catalyst in the oxidation of ethylbenzene.…”

Oxidative Hydroxylation of Aryl Boronic Acid Catalyzed by Co-porphyrin Complexes via Blue-Light Irradiation

“…Decreasing the environmental impact by immobilized metalloporphyrin on chitosan was a catalyst in the oxidation of ethylbenzene to produce less pollution reaction [32]. Chitosan, cheap and eco-friendly, was used to increase the catalytic activity of porphyrin [33].…”