Sodium-Promoted Pd/TiO2 for Catalytic Oxidation of Formaldehyde at Ambient Temperature

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• 作者：Changbin Zhang ; Yaobin Li ; Yafei Wang ; Hong He
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：May 20, 2014
• 年：2014
• 卷：48
• 期：10
• 页码：5816-5822
• 全文大小：419K
• 年卷期：v.48,no.10(May 20, 2014)
• ISSN：1520-5851

文摘

Catalytic oxidation of formaldehyde (HCHO) to CO₂ at ambient conditions is of great interest for indoor HCHO purification. Here, we report that sodium-doped Pd/TiO₂ is a highly effective catalyst for the catalytic oxidation of HCHO at room temperature. It was observed that Na doping has a dramatic promotion effect on the Pd/TiO₂ catalyst and that nearly 100% HCHO conversion could be achieved over the 2Na鈥揚d/TiO₂ catalyst at a GHSV of 95000 h^鈥? and HCHO inlet concentration of 140 ppm at 25 掳C. The mechanism of the Na-promotion effect was investigated by using Brunauer鈥揈mmett鈥揟eller (BET), X-ray diffraction (XRD), CO chemisorption, Temperature-programmed reduction by H₂ (H₂-TPR), X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption of O₂ (O₂-TPD) methods. The results showed that Na species addition can induce and further stabilize a negatively charged and well-dispersed Pd species, which then facilitates the activation of H₂O and chemisorbed oxygen, therefore resulting in the high performance of the 2Na鈥揚d/TiO₂ catalyst for the ambient HCHO destruction.