In-situ plasma regeneration of deactivated Au/TiO2 nanocatalysts during CO oxidation and effect of N2 content
In-situ plasma regeneration of deactivated Au/TiO2 nanocatalysts during CO oxidation and effect of N2 content
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CO氧化过程中失活Au/TiO2纳米催化剂的原位等离子体再生及N2含量的影响
DOI：
10.1016/j.apcatb.2012.02.016
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发表时间：
2012-05-30
影响因子：
22.1
通讯作者：
Zhu, Ai-Min
中科院分区：
文献类型：
--
作者：
Fan, Hong-Yu;Shi, Chuan;Zhu, Ai-Min
在金纳米催化剂具有良好的常温CO氧化能力的驱使下，采用沉积-沉淀法合成了负载型纳米金催化剂(Au/TiO2光催化剂)。为了解决Au/TiO2催化剂在CO氧化过程中的失活问题，采用了N-2/O-2等离子体原位再生的方法。纯氧等离子体可以对失活的Au/TiO2光催化剂进行可逆再生，但在再生过程中，氮气的加入会导致催化剂中毒。额外毒害效应在10%N-2时最严重，在80%N-2时减弱。为了考察Au/TiO2光催化剂表面中毒物种[NOY](S)的形成，用傅立叶变换红外光谱(FT-IR)在线分析了新鲜Au/TiO2光催化剂上N-2/O-2等离子体气态产物，并用程序升温脱附(TPD)、X射线光电子能谱(XPS)、紫外-可见光谱(UV-Vis)和漫反射红外傅里叶变换(DRIFT)光谱对催化剂进行了表征。对等离子体再生前后的Au/TiO2光催化剂进行了透射电子显微镜观察，以排除由于金颗粒大小或形貌变化而引起的中毒效应。(C)2012爱思唯尔B.V.保留所有权利。
Driven by excellent CO oxidation capability of gold nanocatalysts at room temperature, a TiO2 supported Au nanocatalyst (Au/TiO2) was synthesized by deposition-precipitation method. To solve the deactivation issue of Au/TiO2 catalyst during CO oxidation, in-situ regeneration by N-2/O-2 plasma was employed. Pure O-2 plasma could reversibly regenerate the deactivated Au/TiO2 catalyst, however, N-2 addition resulted in an extra catalyst poisoning during regeneration. The extra poisoning effect was the most severe at 10% N-2 and became much weaker at 80% N-2. To investigate the formation of any surface poisoning species [NOy](s) on Au/TiO2 catalyst, gaseous product of N-2/O-2 plasma over fresh Au/TiO2 catalyst was on-line analyzed by FT-IR, followed by catalyst characterization with temperature programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. The Au/TiO2 catalysts before and after plasma regeneration were also measured by transmission electron microscopy (TEM), in order to exclude the poisoning effect arisen from the change in gold particle size or morphology. (C) 2012 Elsevier B.V. All rights reserved.