沉积沉淀法中制备条件对负载型纳米金催化剂性能的影响  

Effect of preparation conditions on the properties of supported nano-gold catalysts in deposition-precipitation

作　　者：何青容 王旭伟 孔维民 刘伊檬 梁云 董艳春 唐敏 周术元 HE Qing-rong;WANG Xu-wei;KONG Wei-min;LIU Yi-meng;LIANG Yun;DONG Yan-chun;TANG Min;ZHOU Shu-yuan(School of Light Industry and Engineering,South China University of Technology,Guangzhou 51064l,China;State Key Laboratory of NBC Protection for Civilian,Beijing 100083,China)

机构地区：[1]华南理工大学轻工科学与工程学院,广东广州510641 [2]国民核生化灾害防护国家重点实验室,北京100083

出　　处：《分子科学学报》2023年第3期207-218,共12页Journal of Molecular Science

基　　金：国家自然科学基金资助项目(21701186);国民核生化灾害防护国家重点实验室科研基金项目(SKLNBC 2019-04)。

摘　　要：CO的高效快速去除以及实现低(常)温催化氧化是现今研究的重点,而以尿素为沉淀剂,采用沉积沉淀法制备得到的低(常)温催化氧化CO负载型纳米金催化剂具有纳米金颗粒粒径更小、均匀分布于载体上的特点.本文对比了不同的搅拌方式、不同氧化铁载体的浸渍次数以及3种纳米金负载量制备条件下获得的Au/FeO_(x)/Al_(2)O_(3)催化剂的物化性质及催化氧化CO活性.结果表明用恒温水浴摇床振荡得到的负载型纳米金催化剂具有更好、更稳定的催化效果;其中,二次浸渍、摇床振荡、负载量为2%的制备条件下,纳米金催化剂具有最强的低温CO催化氧化活性.最后,本文分析了Al_(2)O_(3),FeO_(x)/Al_(2)O_(3)和Au/FeO_(x)/Al_(2)O_(3)在不同温度下的CO催化氧化机理,认为CO催化氧化过程除了有CO_(2)产生,还存在副产物碳酸盐类物种.The efficient and rapid removal of CO and the realization of low(normal)temperature catalytic oxidation is the focus of recent research.Many kinds of supported nano-Au catalysts have been shown to be effective on CO oxidation and have shown that their catalytic activity depends on the type of support used.When urea reacts with water,it will release OH^(-)as the temperature is higher than 60℃,then the deposition effect of Au on the carrier is enhanced.The low(normal)temperature catalytic oxidation of CO supported nano-gold catalyst has the characteristics of smaller size Au nanoparticles and uniform distribution on the carrier,which prepared by deposition-precipitation method and using urea as the precipitator.The requirement to the intensity of supported catalyst prepared by the existing sedimentation method will be greatly increased.Due to the friction and collision between the stirring rotor or the stirring rod and the support,the surface of the carrier will be damaged and the load of gold will be affected.Especially for the catalyst that is loaded with the active component once and then loaded with gold,which will not only reduce the utilization rate of gold in raw materials,but also reduce the load rate of gold.The water bath shaking with constant temperature can control the temperature and oscillation speed of the water bath accurately,so that the whole reaction liquid and materials will be mixed evenly.Moreover,it can avoid the destruction of particles in the process of oscillation reaction effectively.Therefore,in this paper,the catalytic oxidation activity of supported Au nanoparticles by different stirring methods,different impregnation times of FeOxcarriers and three kinds of loading capacity of gold nanoparticles were studied.It was found that the supported nano-Au catalyst obtained by stirring in a water bath has better and more stable catalytic performance.Moreover,the catalyst with secondary impregnation,shaking vibration,and loading capacity of 2% Au nanoparticles had the highest catalytic oxidat

关 键 词：负载型纳米金催化剂 CO催化氧化 沉积沉淀法 摇床振荡 

分 类 号：O614[理学—无机化学]