Catalytic Properties of Cobalt Phthalocyanines Chemically Bonded to Polymer Anchored onto Silochrome Surface

Abstract

<jats:p> Catalytic systems consisting of cobalt phthalocyanine grafted to maleic anhydride-styrene copolymer chemically linked with γ-aminopropylated silochrome have been prepared. In the process of sulfide oxidation with air oxygen the specific catalytic activity of these systems depends strongly on the phthalocyanine concentration in the catalyst. At low phthalocyanine concentrations (below 0.4 × 10<jats:sup>−6</jats:sup> mol g<jats:sup>−1</jats:sup>) the catalytic activity is more than an order of magnitude larger than that of homogeneous catalysts and cobalt phthalocyanine adsorbed on a silochrome surface. The different ways of preparing the catalysts are reflected in the kinetic characteristics of the oxidation process. </jats:p>

A catalyst based on 3,3′,5,5′‐tetra‐tert‐butyl‐4,4′‐stilbenequinone used in the liquid‐phase oxidation of sodium sulfide

“…As shown by previous studies, the most effective method of sulfide sulfur treatment in the wastewater involves its oxidation in atmospheric oxygen in the presence of a catalyst. Several heterogeneous and homogeneous catalysts have been employed to catalyze the reaction between toxic sulfide and oxygen, forming less harmful sulfur compounds such as thiosulfate and sulfate.…”

“…On another note, nontoxic and economical catalysts based on quinone compounds such as 1,4‐naphthoquinone, 1,2‐naphthoquinone‐4‐sulfonic acid sodium salt, polynaphthoquinone, benzoquinone, duroquinone have been recently applied to sulfide sulfur purification, particularly in petrochemical industry of both Japan and the UK. However, the disadvantages of these catalysts include low catalytic activity, high catalyst losses, and the complexity of the catalyst separation after oxidative treatments . With the view to overcoming these drawbacks, we propose a new quinone‐catalyst based on 3,3′,5,5′‐tetra‐tert‐butyl‐4,4′‐stilbenequinone (hereinafter referred to as stilbenequinone or C 30 H 42 O 2 ) that performs high catalytic activity, selectivity, and stability in alkaline media.…”

Covalently Anchored Polymer Immobilized Co(II) Phthalocyanine as Efficient Catalyst for Oxidation of Mercaptans using Molecular Oxygen as Oxidant

“…Covalent grafting of the cobalt phthalocyanines onto the functionalized polymeric supports such as cobalt phthalocyanine grafted to maleic anhydride-styrene copolymer chemically linked with γ-aminopropylated silochrome for the aerobic oxidation of sulfides has been reported. 19 Chen et al 20 reported the synthesis of soluble polymer, poly(N-isopropylacrylamide) supported cobalt phthalocyanine for the oxidation of thiols. Sanchez et al 21 reported the covalent immobilization of metallo(chlorosulfonyl)phthalocyanines of Fe, Co, and Mn to the amino-function-alized acrylic copolymers for the oxidation of 2,4,6-trichlorophenol using hydrogen peroxide as oxidant.…”

“…Therefore, immobilization of the metal complexes via covalent attachment to the functionalized polymers is an interesting approach to facilitate catalyst recovery, recycling, and to reduce effluent contamination. − In addition, these immobilized catalysts resistant to leaching due to the chemical bonding between the support and the metal complex. Covalent grafting of the cobalt phthalocyanines onto the functionalized polymeric supports such as cobalt phthalocyanine grafted to maleic anhydride−styrene copolymer chemically linked with γ-aminopropylated silochrome for the aerobic oxidation of sulfides has been reported . Chen et al reported the synthesis of soluble polymer, poly( N -isopropylacrylamide) supported cobalt phthalocyanine for the oxidation of thiols.…”