Crystal structure of meso ‐substituted pyrazolyl porphyrin complexes and their highly active catalyst for oxidation of alkylbenzenes

Adsorption and photocatalytic properties of porphyrin loaded MIL-101 (Cr) in methylene blue degradation

In this study for the very first time, zinc tetraphenylporphyrin (ZnTPP) was loaded into MIL-101 (Zn[TPP]@MIL-101) to perform an adsorptive and photocatalytic dye removal. The physicochemical attributes of the catalyst were thoroughly determined by the usage of XRD, FTIR, FESEM, BET, UV-vis, and inductively coupled plasma (ICP). The obtained XRD pattern exhibited the phase purity of MIL-101 and its structural stability. The solid-phase diameter of the catalyst was observed to be ~ 270.76 ± 119.95 nm, while its gas adsorption data was indicative of a decrease in the specific surface area after the loading of ZnTPP. The ICP analysis displayed the amount of encapsulated Zn[TPP] (~ 17%) in MIL-101. The UV-vis confirmed the presence of Zn[TPP] in MIL-101 with the lack of any interferences or overlaps with the λ_max of methylene blue (MB) with the support. The dye removal of MB was investigated under dark conditions (adsorption) and UV light (photodegradation). The observed adsorption under dark conditions using Zn[TPP]@MIL-101 (99.27% yield) demonstrated a superior dye removal in comparison to the cases of photodegradation of MB by MIL-101 and Zn[TPP]@MIL-101 or adsorption by MIL-101. In conformity to the gathered results, [ZnTPP] was able to increase the adsorption capacity at pH = 7 at room temperature.

A Keggin-type polyoxometalate-based metal-organic complex as a highly efficient heterogeneous catalyst for the selective oxidation of alkylbenzenes

The direct oxidation of C-H bonds in organic materials into necessary oxygen-containing compounds under mild conditions has attracted increasing attention. A Keggin-type polyoxometalate-based metal-organic complex (MOC), [CuII4Cu^I(H₂trz)₄(C₂O₄)(H₂O)₄(H₃PW_11.18CuII0.82O₄₀)]·8H₂O (1) (H₃trz = 1,2,4-triazole), was designed and synthesized under hydrothermal conditions, and was structurally characterized by single crystal X-ray diffraction, PXRD, IR spectroscopy, TGA, and XPS. Complex 1 is a 3D 4,6,8-connected architecture derived from [Cu₅(H₂trz)₄(C₂O₄)₂(H₂O)₂]_n units and [PW_11.18Cu_0.82O₄₀]^6- anions, which can catalytically oxidize various types of alkylbenzenes. Gas chromatographic analysis showed that complex 1 as a heterogeneous catalyst could effectively catalyze the oxidation of diphenylmethane with 93% conversion and 99% selectivity within 6 h. In addition, the conversion for the catalytic oxidation of ethylbenzene was 96% with 99% selectivity. Compared with some reported catalysts, complex 1 exhibited a better catalytic effect and lower reaction time. Meanwhile, the catalytic oxidation of other benzyl derivatives with complex 1 was also investigated, which indicated that complex 1 possessed excellent catalytic performance.

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

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 × 106 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.