Phản ứng oxy hóa dị thể hợp chất sunfua xúc tác bởi Al(III)- Tetrasulfophthalocyanine trên SiO2

Nghiên cứu điều chế và tính chất của phức Al(III) etrasulfophthalocyanine cố định trên chất mang silica biến tính đã dược mô tả. Những tính chất của vật liệu mới này được xác định bởi các kỹ thuật phân tích nhiệt (TGA), phản xạ khuyếch tán (DRS) và Bet. Phản ứng oxy hóa hợp chất Sunfua trong dung dịch nước bằng oxy xúc tác bởi vật liệu này được thực hiện. Kết quả cho thấy vật liệu có khả năng xúc tác tốt cho phản ứng oxy hóa sunfua khi được chiếu sáng bởi ánh sáng khả kiến. Phân tích sắc ký ion cho thấy sản phẩm của quá trình oxy hóa sunfua bao gồm các ion sunfat, sunfit và thiosunfat.
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Phản ứng oxy hóa dị thể hợp chất sunfua xúc tác bởi Al(III)- Tetrasulfophthalocyanine trên SiO2 Hoi nghi Khoa hoc ky niem 35 ndm Vien Khoa hoc vd Cong nghe Viet Nam - Hd Noi 10.2010 PHAN UNG QUANG OXY HOA DI THE HQfP CHAT SUNFUA XUC TAC BOI A 1 ( I I I ) - T E T R A S U L F O P H T H A L 6 C Y A N I N E TREN SxOj Le Thanh Minh. Phan Thanh Thao, Phan Minh Tan^ institute of Chemical Technology ^Department of Science and Technology of Hochiminh City Email: minhlethanh2002(^yahoo.com Tom tat: Nghien cieu dieu che vd tinh chdt ciia phuc Al(III)-tetrasulfophthalocyanine cd dinh tren chdt mang silica bien tinh da duac md td. Nhieng tinh chdt ciia vdt lieu mdi ndy duac xdc dinh bdi cdc ky thuat phdn tich nhiet (TGA), phdn xg khuyech tdn (DRS) vd BET. Phdn icng oxy hda hap chdt sunfua trong dung dich nude bdng oxy xuc tdc bdi vdt lieu ndy duac thuc hien. Kd qud cho thdy vdt lieu cd khd ndng xuc tdc tdt cho phdn ung oxy hda sunfua khi duac chieu sdng bdi dnh sdng khd kiin. Phdn tich sdc ky ion cho thdy sdn phdm ciia qud trinh oxy hda sunfua bao gdm cdc ion sunfat, sunfit vd thiosunfat. Abstract: The preparation and properties of a phthalocyanine-silica, where the phthalocyanine is covalently bonded to an inorganic netMork, are described. The properties of this new material were determined by TGA, UV-VIS, BET technique. Oxidation of inorganic sulfide in water by molecular oxygen was studied under visible light irradiation in the presence of immobilized Al(III)- tetrasulfophthalocyanine (AlTSPc) on silica gel. The hybrid catalyst exhibited a good capacity for uptake of sulfide ions from water. Ionic chromatography analysis showed that sulfite, thiosulfate and sulfate were the reaction products. 85 Tieu ban: Moi tru&ng vd Ndng luang ISBN: 978-604-913-013-7 1. INTRODUCTION The photocatalytic properties of metallophthalocyanine (MPcs) are of interest in recent decades. Under the illumination of visible light, MPcs have proved to be highly promising as photosensizers due to their intense absorption in the red region of visible light. High triplet state quantum yields and long-lifetimes are required for efficient sensitization and these criteria may be fulfilled by the incorporation of a diamagnetic metal such as zinc, aluminum, silicon into the pbthalocyanine compounds [1]. Aluminum tetrasulfophthalocyanine (AlTSPc) complexes have attracted a great deal of interest because of their appreciably long triplet lifetime. This is a great advantage since the number of diffusional encounters between the triplet excited state of AlTSPc and ground state molecular oxygen increase. The result of that is singlet oxygen as a strong oxidative agent produced. Water soluble complexes of AlTSPc display a high photo-catalyst under visible light irradiation. The immobilization of pbthalocyanine by covalent bonding to catalytically inert surfaces, such as silica gel, is a prospective approach to achieve heterogeneous catalysts exhibiting well-defined dispersions of the active component. The aim of this paper is to study the preparation of AlTSPc complexes supported on silica gel carrier and use as catalyst in the oxidation of the sulfide anion. 2. EXPERIMENTAL 2.1 Materials and methods - AlTSPc was synthesized in Institute of Chemical Technology as literature [6]. - Na2S.9H20, SOCI2, Zn(CH3COO)2, dimethylformamide (DMF) N,N-dimethyl-p- phenylendiamin.2HCl, 3-aminopropyltriethoxysilane, xylene were purchased from Merck. C2H5OH, (NH4)2HP04, FeCl3, toluene, ether were purchased from Shanghai Chemicals. Si02 (60-200 Mesh-Merck) was dried in vacuum (100 mmHg) at 200°C for 4 hours. - The UV-VIS diffuse reflection absorption spectra of solid catalysts were recorded on a UV-VIS Spectrometer V530 (Shimadzu). The BET surface area and pore size distributions of the materials were determined by nitrogen adsorption at 77K, with a NOVA 2200 instrument. Elemental analysis for carbon, hydrogen, nitrogen and sulfur was done by Element Analyzer YEAl 12. Thermal gravimetric analysis measurements were made in air with a heating rate of lO^C min, from 25 to 1000 °C by DTG-60 (Shimadzu). Light intensity was measured with a silicon photodiode (Voltcraft MS-1300). The pH of reaction was controlled by pH meter (pH controller 500-Hanna). - Sulfide concentration was measured by photometric method on DR/2000 equipment (Hach). This method was based on photometric color measurement of methylene blue compound produced from the reacfion of sulfide, N,N-dimethyl-p-phenylenediamine.2HCl and FeCl3 at a wavelength of 750nm [8]. - Degree of lo ...