四氧化三钴负载金钯纳米催化剂催化消除甲苯和邻二甲苯（英文）
发布时间：2018-12-15 08:21
【摘要】：挥发性有机物(VOCs,例如甲苯和二甲苯)不仅危害人身健康,而且对大气环境造成严重污染.由于去除效率高、无二次污染以及耗能低等优点,催化氧化法被认为是消除VOCs的有效方法之一.该方法的关键是高效催化剂的研发.由于具有良好的低温催化氧化性能,过渡金属氧化物负载的贵金属催化剂备受关注.相比于单组分贵金属负载型催化剂,双组分贵金属负载型催化剂的催化活性、水热稳定性能和抗硫中毒性能均有显著提高.本文采用熔融盐法和聚乙烯醇保护的硼氢化钠还原法制备了八面体状Co_3O_4负载的AuPd(x(AuPd_y)/Co_3O_4;AuPd负载量x=(0.18,0.47,0.97)wt%;Pd/Au摩尔比y=1.85,1.93,1.92)合金纳米催化剂.采用X射线衍射、扫描电子显微镜、透射电子显微镜、选区电子衍射、氢气程序升温还原、氧气程序升温脱附和X射线光电子衍射等技术对催化剂物化性质进行了表征.利用固定床微型反应器评价了催化剂对甲苯和邻二甲苯完全氧化反应的催化性能.研究结果表明,采用熔融盐法制得的Co_3O_4具有规整八面体形貌,棱长约为300 nm.AuPd合金纳米粒子均匀分布在Co_3O_4表面,粒径为2.7-3.2 nm.在所得催化剂中,0.96(AuPd_(1.92))/Co_3O_4催化剂对甲苯和邻二甲苯完全氧化反应表现出较高的催化活性.在空速为40000 mL/(g·h)时,甲苯和邻二甲苯转化率达到90%所需的温度分别为180和187℃.我们认为0.96(AuPd_(1.92))/Co_3O_4催化剂较为优异的催化性能与AuPd纳米粒子和Co_3O_4之间的强相互作用和较高的吸附氧浓度有关.
[Abstract]:Volatile organic compounds (VOCs, such as toluene and xylene) not only endanger human health, but also cause serious environmental pollution. Because of the advantages of high removal efficiency, no secondary pollution and low energy consumption, catalytic oxidation is considered to be one of the effective methods to eliminate VOCs. The key of this method is the research and development of high efficient catalyst. Due to their good catalytic performance at low temperature, transition metal oxide supported noble metal catalysts have attracted much attention. Compared with single-component noble metal supported catalysts, the catalytic activity, hydrothermal stability and sulfur poisoning resistance of two-component noble metal supported catalysts were significantly improved. In this paper, the octahedron Co_3O_4 loaded AuPd (x (AuPd_y / Co_3O_4;AuPd was prepared by melt salt method and polyvinyl alcohol protected sodium borohydride reduction method. The molar ratio of Pd/Au is 1.85%, 1.93% and 1.92%, respectively. The physicochemical properties of the catalyst were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, selective electron diffraction, hydrogen temperature programmed reduction, oxygen temperature programmed desorption and X-ray photoelectron diffraction. The catalytic performance of the catalyst for the complete oxidation of toluene and o-xylene was evaluated by a fixed bed microreactor. The results show that the Co_3O_4 prepared by molten salt method has regular octahedron morphology, the edge length is about 300 nm.AuPd alloy nanoparticles distributed uniformly on the surface of Co_3O_4, and the particle size is 2.7-3.2 nm.. Among the obtained catalysts, 0.96 (AuPd_ (1.92) / Co_3O_4 showed high catalytic activity for the complete oxidation of toluene and o-xylene. When the space velocity is 40000 mL/ (g h), the temperature required for the conversion of toluene and o-xylene to reach 90% is 180 鈩，
本文编号：2380332
[Abstract]:Volatile organic compounds (VOCs, such as toluene and xylene) not only endanger human health, but also cause serious environmental pollution. Because of the advantages of high removal efficiency, no secondary pollution and low energy consumption, catalytic oxidation is considered to be one of the effective methods to eliminate VOCs. The key of this method is the research and development of high efficient catalyst. Due to their good catalytic performance at low temperature, transition metal oxide supported noble metal catalysts have attracted much attention. Compared with single-component noble metal supported catalysts, the catalytic activity, hydrothermal stability and sulfur poisoning resistance of two-component noble metal supported catalysts were significantly improved. In this paper, the octahedron Co_3O_4 loaded AuPd (x (AuPd_y / Co_3O_4;AuPd was prepared by melt salt method and polyvinyl alcohol protected sodium borohydride reduction method. The molar ratio of Pd/Au is 1.85%, 1.93% and 1.92%, respectively. The physicochemical properties of the catalyst were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, selective electron diffraction, hydrogen temperature programmed reduction, oxygen temperature programmed desorption and X-ray photoelectron diffraction. The catalytic performance of the catalyst for the complete oxidation of toluene and o-xylene was evaluated by a fixed bed microreactor. The results show that the Co_3O_4 prepared by molten salt method has regular octahedron morphology, the edge length is about 300 nm.AuPd alloy nanoparticles distributed uniformly on the surface of Co_3O_4, and the particle size is 2.7-3.2 nm.. Among the obtained catalysts, 0.96 (AuPd_ (1.92) / Co_3O_4 showed high catalytic activity for the complete oxidation of toluene and o-xylene. When the space velocity is 40000 mL/ (g h), the temperature required for the conversion of toluene and o-xylene to reach 90% is 180 鈩，
本文编号：2380332
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