Porphyrins and Phthalocyanines on Solid-State Mesoporous Matrices as Catalysts in Oxidation Reactions

Abstract

The review presents recent examples of heterogenic catalysts based on porphyrins and phthalocyanines loaded on mesoporous materials, such as MCM-41, SBA-15, MCM-48, SBA-16 or Al-MCM-41. Heterogenic approach to catalysis eases recovery, reuse and prevent macrocycle aggregation. In this application, mesoporous silica is a promising candidate for anchoring macrocycle and obtaining a new catalyst. Introduction of porphyrin or phthalocyanine into the mesoporous material may be performed through adsorption of the macrocycle, or by its in situ formation—by reaction of substrates introduced to the pores of the catalytic material. Catalytic reactions studied are oxidation processes, focused on alkane, alkene or arene as substrates. The products obtained are usually epoxides, alcohols, ketones, aldehydes or acids. The greatest interest lies in oxidation of cyclohexane and cyclohexene, as a source of adypic acid and derivatives. Some of the reactions may be viewed as biomimetic processes, resembling processes that occur in vivo and are catalyzed by cytochrome P450 enzyme family.

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

“…Porphyrin and metalloporphyrin complexes present peculiar physicochemical characteristics and are easily tunable, which offers the possibility of being used in a good number of technological applications in fields such as biomedical applications, solar cells, chemical and biochemical sensors, and nanowires/nanomotors [ 1 , 2 , 3 , 4 , 5 ]. 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.…”

“…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.…”

“…Therefore, the search for new applications of these V-containing petroporphyrins is highly interesting. 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 ].…”

“…Vanadyl-porphyrins present interesting electrical properties [ 13 , 24 , 25 , 26 , 27 ] and could be of interest to be used as catalysts in electrochemical reactions. However, to the best of our understanding, no research article has been published that focused on the photoelectrochemical characteristics of bulk and supported vanadyl-porphyrins.…”

A Porphyrin-Based Covalent Organic Framework as Metal-Free Visible-LED-Light Photocatalyst for One-Pot Tandem Benzyl Alcohol Oxidation/Knoevenagel Condensation

“…However, homogenous, synthetic porphyrin-based catalysts irreversibly self-deactivate or self-destruct in solutions by forming inactive bimolecular species [ 4 , 5 ]. In order to address this problem, porphyrins have been tethered on solid supports or incorporated in porous architectures for their use in heterogeneous catalysis [ 6 , 7 , 8 ], water remediation [ 9 ], and hydrogen production [ 10 ]. Nevertheless, in spite of these successful achievements, some of the materials reported display a low active site density per mass unit, which is detrimental to achieving high reaction rates.…”