Structural and Catalytic Investigation of Mesoporous Iron Phosphate

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• 作者：Dinghua Yu ; Cheng Wu ; Yan Kong ; Nianhua Xue ; Xuefeng Guo ; Weiping Ding
• 刊名：Journal of Physical Chemistry C
• 出版年：2007
• 出版时间：October 4, 2007
• 年：2007
• 卷：111
• 期：39
• 页码：14394 - 14399
• 全文大小：305K
• 年卷期：v.111,no.39(October 4, 2007)
• ISSN：1932-7455

文摘

The local structure of ordered mesoporous iron phosphate, prepared through coassembly of inorganic speciesand sodium dodecyl sulfate template under the assistance of HF, has been investigated with severalphysicochemical methods, including small-angle XRD, TG-DSC, and combined spectroscopic characterizationof FT-IR, Far-IR, Raman, UV-vis, and XPS. The redox property has also been measured by using the H₂-TPR method. The results of TEM and nitrogen sorption show the mesoporous iron phosphate possesses awell-established mesostructure, narrow pore size distribution, and large surface area (423 m²/g). The resultsof the spectroscopic characterization reveal that the mesoporous iron phosphate has specific iron-oxygenand phosphorus-oxygen local environment, differing from those in its crystalline counterpart. Comparedwith a crystalline sample, the iron-oxygen polyhedrons in the mesoporous sample shows a characteristic ofdistorted configuration, while the phosphate roots have a shorter P-O bond. Fluorine species are detected byXPS measurement. These factors cause the reduction by hydrogen of the mesoporous iron phosphate to bedifficult. The hydroxylation reaction of phenol in glacial acetic acid by hydrogen peroxide has been used asa probe reaction to test the catalytic property of the mesoporous iron phosphate. Better catalytic performanceand unique distribution of products has been observed on the mesoporous sample, compared to the crystallineion phosphate. Finally, a model about the surface structure and reaction network of the hydroxylation ofphenol on iron phosphate is proposed.