针对室内环境PM_(2.5)污染问题,设计了一台空气净化器,以强电场介质(Intense Field Dielectric,IFD)装置作为其核心过滤元件。在上海某办公室,以香烟烟雾为PM_(2.5)发生源,测试了净化器的一次过滤效率、风量、能耗、臭氧发生量,以及不同档位运行工况下室内PM_(2.5)质量浓度衰减情况和换气次数,并计算了各档位的洁净空气量(Clean Air Delivery Rate,CADR)和净化效能。结果表明,IFD装置能够有效净化实际环境中的高浓度PM_(2.5),其臭氧发生量符合环境要求。空气净化器在2档运行时,CADR和净化效能均较大。
Flame spray pyrolysis （FSP） was utilized to synthesize Ce-Mn oxides in one step for catalytic oxidation of benzene. Cerium acetate and manganese acetate were used as precursors. The materials synthesized were characterized using X-ray diffraction （XRD）, N2 adsorption, X-ray photoelectron spectroscopy （XPS）, transmission electron microscopy （TEM）, Raman spectroscopy, and H2-temperature programmed reduc- tion （H2-TPR） and their benzene catalytic oxidation behavior was evaluated. Mn ions were evidenced in multiple chemical states. Crystalline Ce-Mn oxides consist of particles with size 〈40 nm and specific sur- face areas （SSA） of 20-50 m2/g. Raman spectrums and H2-TPR results indicated the interaction between cerium and manganese oxides. Flame-made 12.5%-Ce-Mn oxide exhibited excellent catalytic activity at relatively low temperatures （T95 about 260℃） compared to other Ce-Mn oxides with different cerium- to-manganese ratios, Redox mechanism and strong interaction conform to structure analysis that Ce-Mn strong interaction formed during the high temperature flame process and the results were used to explain catalytic oxidation of benzene.
Gang LiuRenliang YueYi JiaYong NiJie YangHaidi LiuZhen WangXiaofeng WuYunfa Chen
