Yi Zhihao, Sun Jie, Li Jigang, Yang Yulin, Zhou Tian, Wei Shouping, Zhu Anna
State Key Laboratory of NBC Protection for Civilian Beijing 102205 China.
Department of Chemistry Defense, Institute of NBC Defense Beijing 102205 China
RSC Adv. 2021 Feb 26;11(15):8886-8896. doi: 10.1039/d0ra10177j. eCollection 2021 Feb 23.
In this work, porous CeO flower-like spheres loaded with bimetal oxides were prepared to achieve effective removal of HCN in the lower temperature region of 30-150 °C. Among all samples, the CeO loaded with copper and manganese oxides at the mass ratio of 8/2 (CuMn/CeO) exhibited the highest catalytic activity: the HCN removal rate was nearly 100% at 90 °C at the conditions of 120 000 h and 5 vol% HO, the catalytic activity of which was higher than for other reported catalysts. The introduction of MnO could improve the dispersion of CuO particles and increase the total acid sites of the prepared samples. It was proved that the synergy between CuO and MnO , the chemisorption oxygen, the oxygen vacancies, the Cu and Mn all played an important role in determining the good catalytic activity of the prepared samples. NH-TPD analysis indicated the introduction of MnO promoted the conversion of NH and N selectivity by increasing the acid sites of the sample. According to the C, N balance data and FT-IR results, when the temperature was below 30 °C, the removal of HCN over CuMn/CeO was mainly by chemisorption and the HCN breakthrough behaviors corresponded to the Yoon and Nelson's model. When temperature was above 120 °C, the HCN was totally removed by catalytic hydrolysis and catalytic oxidation.
在这项工作中，制备了负载双金属氧化物的多孔CeO花状球体，以实现在30 - 150℃的较低温度区域有效去除HCN。在所有样品中，负载质量比为8/2的铜和锰氧化物的CeO（CuMn/CeO）表现出最高的催化活性：在120000 h⁻¹和5 vol% H₂O的条件下，90℃时HCN去除率接近100%，其催化活性高于其他报道的催化剂。MnO₂的引入可以改善CuO颗粒的分散性并增加制备样品的总酸位。结果表明，CuO与MnO₂之间的协同作用、化学吸附氧、氧空位、Cu和Mn在决定制备样品良好的催化活性方面都起到了重要作用。NH₃-TPD分析表明，MnO₂的引入通过增加样品的酸位促进了NH₃的转化和N₂选择性。根据C、N平衡数据和FT-IR结果，当温度低于30℃时，CuMn/CeO上HCN的去除主要通过化学吸附，HCN穿透行为符合Yoon和Nelson模型。当温度高于120℃时，HCN通过催化水解和催化氧化被完全去除。
