Catalytic Decomposition of Toxic Chemicals over Metal-Promoted Carbon Nanotubes

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• 作者：Lili Li ; Changxiu Han ; Xinyu Han ; Yixiao Zhou ; Li Yang ; Baogui Zhang ; Jianli Hu
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：January 15, 2011
• 年：2011
• 卷：45
• 期：2
• 页码：726-731
• 全文大小：248K
• 年卷期：v.45,no.2(January 15, 2011)
• ISSN：1520-5851

文摘

Effective decomposition of toxic gaseous compounds is important for pollution control at many chemical manufacturing plants. This study explores catalytic decomposition of phosphine (PH₃) using novel metal-promoted carbon nanotubes (CNTs). The cerium-promoted Co/CNTs catalysts (CoCe/CNTs) are synthesized by means of coimpregnation method and reduced by three different methods (H₂, KBH₄, NaH₂PO₂路H₂O/KBH₄). The morphology, structure, and composition of the catalysts are characterized using a number of analytical instrumentations including high-resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, BET surface area measurement, and inductively coupled plasma. The activity of the catalysts in PH₃ decomposition reaction is measured and correlated with their surface and structural properties. The characterization results show that the CoCe/CNTs catalyst reduced by H₂ possesses small particles and is shown thermally stable in PH₃ decomposition reaction. The activities of these catalysts are compared and are shown in the following sequence: CoCe/CNTs > Co/CNTs > CoCeBP/CNTs> CoCeB/CNTs. The difference in reduction method results in the formation of different active phases during the PH₃ decomposition reaction. After a catalytic activity test, only the CoP phase is formed on CoCe/CNTs and Co/CNTs catalysts, whereas multiphases CoP, Co₂P, and Co phases are formed on CoCeBP/CNTs and CoCeB/CNTs. Results show that the CoP phase is formed predominantly on the CoCe/CNTs and Co/CNTs catalysts and is found to likely be the most active phase for this reaction. Furthermore, the CoCe/CNTs catalyst exhibits not only highest activity but also long-term stability in PH₃ decomposition reaction. When operated in a fixed-bed reactor at 360 掳C, single-pass PH₃ conversion of about 99.8% can be achieved.