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采用共沉淀法和等体积浸渍法制备了CuCeO x复合催化剂,对材料的物化性质进行了XRD、低温N2吸脱附、H2-TPR和O2-TPD表征.以石化行业典型VOCs(苯、甲苯和正己烷)为探针污染物,研究了污染物组成与浓度、反应空速、O2浓度、H2O浓度和催化剂种类对其氧化行为的影响,并对反应动力学参数进行了模型拟合.共沉淀得到的催化剂具有均匀的活性相、好的低温可还原性能和较多的活性表面氧物种.甲苯氧化率随着污染物浓度升高而降低,高转化率下苯浓度与其氧化率无相关性,正己烷的氧化率与入口浓度呈正比.苯能够显著抑制甲苯的氧化,而甲苯加入有利于苯的氧化.正己烷对苯氧化的影响较小,但能够促进甲苯的转化,苯系物对正己烷氧化有明显的抑制作用.低空速和高氧浓度都有利于污染物的氧化,氧浓度的变化对正己烷和苯的氧化影响较小.水汽对甲苯的氧化有明显的抑制作用,而对苯和正己烷氧化有明显的促进作用.共沉淀催化剂具有更好的甲苯和苯氧化性能,而无水条件下浸渍催化剂具有更好的正己烷氧化性能.拟一级动力学模型能够很好地模拟不同条件下污染物的氧化行为.
The CuCeO x composite catalysts were prepared by coprecipitation method and isothermal impregnation method. The physico-chemical properties of the materials were characterized by XRD, N2 adsorption and desorption, H2-TPR and O2-TPD. The typical VOCs (benzene, N-hexane) as probe pollutants, the effects of pollutant composition and concentration, reaction space velocity, O2 concentration, H2O concentration and catalyst type on the oxidation behavior were studied, and the reaction kinetics parameters were modeled. The obtained catalyst has uniform active phase, good low temperature reducibility and more active surface oxygen species.The toluene oxidation rate decreases with the increase of pollutant concentration, the benzene concentration at high conversion has no correlation with its oxidation rate, The oxidation rate of n-hexane is proportional to the inlet concentration. Benzene can significantly inhibit the oxidation of toluene, while the addition of toluene is beneficial to the oxidation of benzene.N-hexane has little effect on the oxidation of benzene, but it can promote the conversion of toluene, Alkane oxidation significantly inhibited the low space velocity and high oxygen concentrations are conducive to the oxidation of pollutants, oxygen concentration changes on the oxidation of n-hexane and benzene less water oxidation of toluene significantly inhibited , While benzene and n-hexane oxidation significantly promote the role of coprecipitated catalyst has better toluene and benzene oxidation performance, and under anhydrous impregnation catalyst has better n-hexane oxidation performance. Quasi-first-order kinetic model It can well simulate the oxidation behavior of pollutants under different conditions.