Zinc Oxide Supported trans-CoD(p-Cl)PPCl-Type Metalloporphyrins Catalyst for Cyclohexane Oxidation to Cyclohexanol and Cyclohexanone with High Yield

Efficient oxidation of cumene to cumene hydroperoxide with ambient O2 catalyzed by metalloporphyrins

A novel and efficient protocol for oxidation of cumene to cumene hydroperoxide was presented using ambient O2 catalyzed by very simple metalloporphyrins. The selectivity toward cumene hydroperoxide reached 98.3% in the cumene conversion of 28.1% with T(4-COOH)PPCu as a catalyst at 80[Formula: see text]C. The origin of the higher performance of T(4-COOH)PPCu was mainly ascribed to the low catalytic performance of copper(II) in the cumene hydroperoxide decomposition, and the ability of T(4-COOH)PP in stabilizing cumene hydroperoxide through hydrogen-bond interactions between them. Compared with current industrial processes and academic research in oxidation of cumene to cumene hydroperoxide with O2, the main superiorities of this protocol were the high selectivity, high conversion, simple catalysts, solvent-free, additive-free and mild conditions which made this work an appealing reference for the industrial oxidation of cumene to cumene hydroperoxide, as well as the oxidative functionalization of other C-H bonds in various hydrocarbons.

Catalytic oxidation of cycloalkanes by porphyrin cobalt(II) through efficient utilization of oxidation intermediates

The catalytic oxidation of cycloalkanes using molecular oxygen employing porphyrin cobalt(II) as catalyst was enhanced through use of cycloalkyl hydroperoxides, which are the primary intermediates in oxidation of cycloalkanes, as additional oxidants to further oxidize cycloalkanes in the presence of porphyrin copper(II), especially for cyclohexane, for which the selectivity was enhanced from 88.6 to 97.2% to the KA oil; at the same time, the conversion of cyclohexane was enhanced from 3.88 to 4.41%. The enhanced efficiency and selectivity were mainly attributed to the avoided autoxidation of cycloalkanes and efficient utilization of oxidation intermediate cycloalkyl hydroperoxides as additional oxidants instead of conventional thermal decomposition. In addition to cyclohexane, the protocol presented in this research is also very applicable in the oxidation of other cycloalkanes such as cyclooctane, cycloheptane and cyclopentane, and can serve as a applicable and efficient strategy to boost the conversion and selectivity simultaneously in oxidation of alkanes. This work also is a very important reference for the extensive application of metalloporphyrins in catalysis chemistry.

Selective Cl-Decoration on Nanocrystal Facets of Hematite for High-Efficiency Catalytic Oxidation of Cyclohexane: Identification of the Newly Formed Cl-O as Active Sites

Understanding the structure-reactivity relationship at the atomic scale is of great theoretical importance for rational design of highly active catalysts, which has long been a central concern in catalysis communities and interface science. Herein, we developed a high-efficiency catalyst for catalytic oxidation of C₆H₁₂ by poststructural decoration on well-defined single-crystal facets of hematite. Especially for Cl-decorated {012} facets, the conversion and KA oil selectivity are improved about 3.4 times and 2 times, respectively. A better catalytic performance of the newly formed active site is derived from the charge difference between Cl and the neighboring outmost O atoms, which is affected by the geometric and electronic structures of the original catalyst surface. Based on the experimental results and the theoretical analysis, we concluded that the contribution of various O terminations to Cl-decoration follows the order O(I) > O(III) > O(II). Cl-decorated {001} facets show the highest intrinsic activity, whereas Cl-decorated {012} facets show the best catalytic performance because of their more active sites for Cl-decoration.

Acetylacetone as an oxygen activator to improve efficiency for aerobic oxidation of toluene and its derivatives by using cobalt meso-tetraphenylporphyrin

An efficient system comprising acetylacetone and cobalt tetraphenylporphyrin was developed for the aerobic oxidation of toluene and its derivatives, in which acetylacetone served as the key initiator of the free radical in activating dioxygen.

“Ship in a bottle” Porph@MOMs as highly efficient catalysts for selective controllable oxidation and insights into different mechanisms in heterogeneous and homogeneous environments

3D “ship in a bottle” Porph@MOMs with selectivity control capability and interesting catalytic properties were used as biomimetic oxidation catalysts for different reactions.

Recent Advances in Solid Catalysts Obtained by Metalloporphyrins Immobilization on Layered Anionic Exchangers: A Short Review and Some New Catalytic Results

Layered materials are a very interesting class of compounds obtained by stacking of two-dimensional layers along the basal axis. A remarkable property of these materials is their capacity to interact with a variety of chemical species, irrespective of their charge (neutral, cationic or anionic). These species can be grafted onto the surface of the layered materials or intercalated between the layers, to expand or contract the interlayer distance. Metalloporphyrins, which are typically soluble oxidation catalysts, are examples of molecules that can interact with layered materials. This work presents a short review of the studies involving metalloporphyrin immobilization on two different anionic exchangers, Layered Double Hydroxides (LDHs) and Layered Hydroxide Salts (LHSs), published over the past year. After immobilization of anionic porphyrins, the resulting solids behave as reusable catalysts for heterogeneous oxidation processes. Although a large number of publications involving metalloporphyrin immobilization on LDHs exist, only a few papers have dealt with LHSs as supports, so metalloporphyrins immobilized on LHSs represent a new and promising research field. This work also describes new results on an anionic manganese porphyrin (MnP) immobilized on Mg/Al-LDH solids with different nominal Mg/Al molar ratios (2:1, 3:1 and 4:1) and intercalated with different anions (CO₃²⁻ or NO₃⁻). The influence of the support composition on the MnP immobilization rates and the catalytic performance of the resulting solid in cyclooctene oxidation reactions will be reported.

Oxygen oxidation of ethylbenzene over manganese porphyrin is promoted by the axial nitrogen coordination in powdered chitosan

A less wasteful production method of oxidation ethylbenzene to acetophenone and phenethyl alcohol was adviced. It revealed an important role in tuning catalytic reactivity of metalloporphyrins by the axial ligand for oxidation of hydrocarbon.

Catalytic oxidation of cyclohexane by substituted metalloporphyrins: experimental and molecular simulation

The metalloporphyrins and metalloporphyrin intermediates with lower energy gap have stronger ability to activate the oxygen and cyclohexane respectively.