College of Chemistry and Chemical Engineering, Bohai University, Jinzhou 121013, China; Key Laboratory of Beijing on Regional Air Pollution Control, Beijing Key Laboratory for Green Catalysis and Separation, MOE Key Laboratory of Enhanced Heat Transfer and Energy Conservation, and College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China.
Key Laboratory of Beijing on Regional Air Pollution Control, Beijing Key Laboratory for Green Catalysis and Separation, MOE Key Laboratory of Enhanced Heat Transfer and Energy Conservation, and College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China.
J Environ Sci (China). 2018 Feb;64:276-288. doi: 10.1016/j.jes.2017.06.025. Epub 2017 Jun 30.
α-MnO nanotubes and their supported Au-Pd alloy nanocatalysts were prepared using hydrothermal and polyvinyl alcohol-protected reduction methods, respectively. Their catalytic activity for the oxidation of toluene/m-xylene, acetone/ethyl acetate, acetone/m-xylene and ethyl acetate/m-xylene mixtures was evaluated. It was found that the interaction between Au-Pd alloy nanoparticles and α-MnO nanotubes significantly improved the reactivity of lattice oxygen, and the 0.91wt.% AuPd/α-MnO nanotube catalyst outperformed the α-MnO nanotube catalyst in the oxidation of toluene, m-xylene, ethyl acetate and acetone. Over the 0.91wt.% AuPd/α-MnO nanotube catalyst, (i) toluene oxidation was greatly inhibited in the toluene/m-xylene mixture, while m-xylene oxidation was not influenced; (ii) acetone and ethyl acetate oxidation suffered a minor impact in the acetone/ethyl acetate mixture; and (iii) m-xylene oxidation was enhanced whereas the oxidation of the oxygenated VOCs (volatile organic compounds) was suppressed in the acetone/m-xylene or ethyl acetate/m-xylene mixtures. The competitive adsorption of these typical VOCs on the catalyst surface induced an inhibitive effect on their oxidation, and increasing the temperature favored the oxidation of the VOCs. The mixed VOCs could be completely oxidized into CO and HO below 320°C at a space velocity of 40,000mL/(g·hr). The 0.91wt.% AuPd/α-MnO nanotube catalyst exhibited high catalytic stability as well as good tolerance to water vapor and CO in the oxidation of the VOC mixtures. Thus, the α-MnO nanotube-supported noble metal alloy catalysts hold promise for the efficient elimination of VOC mixtures.
采用水热法和聚乙烯醇保护还原法分别制备了α-MnO 纳米管及其负载的 Au-Pd 合金纳米催化剂。评价了它们对甲苯/间二甲苯、丙酮/乙酸乙酯、丙酮/间二甲苯和乙酸乙酯/间二甲苯混合物氧化的催化活性。结果表明，Au-Pd 合金纳米粒子与α-MnO 纳米管之间的相互作用显著提高了晶格氧的反应活性，0.91wt.%AuPd/α-MnO 纳米管催化剂在甲苯、间二甲苯、乙酸乙酯和丙酮的氧化反应中优于α-MnO 纳米管催化剂。在 0.91wt.%AuPd/α-MnO 纳米管催化剂上，（i）甲苯/间二甲苯混合物中甲苯氧化反应受到强烈抑制，而间二甲苯氧化反应不受影响；（ii）在丙酮/乙酸乙酯混合物中，丙酮和乙酸乙酯氧化反应受到轻微影响；（iii）间二甲苯氧化反应增强，而含氧 VOCs（挥发性有机化合物）的氧化反应受到抑制。这些典型 VOCs 在催化剂表面的竞争吸附对它们的氧化产生了抑制作用，提高温度有利于 VOCs 的氧化。在空速为 40,000mL/(g·hr)时，混合 VOCs 可在 320°C 以下完全氧化为 CO 和 HO。在氧化 VOC 混合物时，0.91wt.%AuPd/α-MnO 纳米管催化剂表现出高催化稳定性以及对水蒸气和 CO 的良好耐受性。因此，α-MnO 纳米管负载的贵金属合金催化剂有望高效消除 VOC 混合物。
