Catalytic oxidation is regarded as one of the most promising strategies for volatile organic compounds(VOCs)purification.Mixed metal oxides(MMOs),after topological transformation using layered double hydroxides(LDHs)a...Catalytic oxidation is regarded as one of the most promising strategies for volatile organic compounds(VOCs)purification.Mixed metal oxides(MMOs),after topological transformation using layered double hydroxides(LDHs)as precursors,are extensively used as catalysts for VOCs oxidation due to their uniformity advantage.This review summarizes the developments in the LDH-derived VOCs heterogeneous catalytic oxidation over the last 10 years.Particularly,it addresses the VOCs abatement performance over MMO,noble metal/MMO,core-shell structured MMO,and integral MMO film catalysts originating from LDHs.Moreover,it highlights the water vapor effect and oxidation mechanism.This review indicates that LDH-based catalysts are a category of important VOCs oxidation materials.展开更多
The aggregation and fractal structure of mixed metal hydroxides ( MMH ) agglomerates with increasing ionic strength have been studied by dynamic light scattering ( DLS ) and SEM techniques. The experiments indicate th...The aggregation and fractal structure of mixed metal hydroxides ( MMH ) agglomerates with increasing ionic strength have been studied by dynamic light scattering ( DLS ) and SEM techniques. The experiments indicate that the MMH agglomerates have two different structures in RLA regime and DLA regime, and also give the proof that the transition region between RLA and DLA may occur.展开更多
The thixotropy of suspension, the rheological properties change with the increase of shear time, is a complicated rheological phenomenon. The shear thinning and the shear thickening phenomena, i.e ., positive thixotro...The thixotropy of suspension, the rheological properties change with the increase of shear time, is a complicated rheological phenomenon. The shear thinning and the shear thickening phenomena, i.e ., positive thixotropy and negative thixotropy, were observed respectively in the previous studies. Recently we found a novel thixotropic phenomenon, described as "complex thixotropy", during studying the thixotropic phenomenon of magnesium aluminum hydroxide montmorillonite suspension. The study of thixotropy of the aqueous suspension consisting of magnesium aluminum hydroxide(Mg Al MMH)possessing permanent positive and Kaolinite possessing permanent negative charges is reported. The suspensions studied may display a positive thixotropy and complex phenomenon successively in various Mg Al MMH/kaolinite ratios 0-0.16 examined. The effect of shear rate( D L)used in measuring viscosity on the thixotropy of the suspension was investigated, and the mechanism of the thixotropy was discussed.展开更多
基金supported by the National Key R&D Program of China(2017YFC0211503,2016YFC0207100)the Strategic Priority Research Program(A)of the Chinese Academy of Sciences(XDA23030300)+2 种基金the National Natural Science Foundation of China(21401200,51672273)the Open Research Fund of State Key Laboratory of Multi-phase Complex Systems(MPCS-2017-D-06)the Young Talent Project of the Center for Excellence in Regional Atmospheric Environment,CAS(CERAE201805)~~
文摘Catalytic oxidation is regarded as one of the most promising strategies for volatile organic compounds(VOCs)purification.Mixed metal oxides(MMOs),after topological transformation using layered double hydroxides(LDHs)as precursors,are extensively used as catalysts for VOCs oxidation due to their uniformity advantage.This review summarizes the developments in the LDH-derived VOCs heterogeneous catalytic oxidation over the last 10 years.Particularly,it addresses the VOCs abatement performance over MMO,noble metal/MMO,core-shell structured MMO,and integral MMO film catalysts originating from LDHs.Moreover,it highlights the water vapor effect and oxidation mechanism.This review indicates that LDH-based catalysts are a category of important VOCs oxidation materials.
基金supported by the National Natural Science Foundation of China(No.20273041)the Ministry of the Education.
文摘The aggregation and fractal structure of mixed metal hydroxides ( MMH ) agglomerates with increasing ionic strength have been studied by dynamic light scattering ( DLS ) and SEM techniques. The experiments indicate that the MMH agglomerates have two different structures in RLA regime and DLA regime, and also give the proof that the transition region between RLA and DLA may occur.
文摘The thixotropy of suspension, the rheological properties change with the increase of shear time, is a complicated rheological phenomenon. The shear thinning and the shear thickening phenomena, i.e ., positive thixotropy and negative thixotropy, were observed respectively in the previous studies. Recently we found a novel thixotropic phenomenon, described as "complex thixotropy", during studying the thixotropic phenomenon of magnesium aluminum hydroxide montmorillonite suspension. The study of thixotropy of the aqueous suspension consisting of magnesium aluminum hydroxide(Mg Al MMH)possessing permanent positive and Kaolinite possessing permanent negative charges is reported. The suspensions studied may display a positive thixotropy and complex phenomenon successively in various Mg Al MMH/kaolinite ratios 0-0.16 examined. The effect of shear rate( D L)used in measuring viscosity on the thixotropy of the suspension was investigated, and the mechanism of the thixotropy was discussed.
基金supported by the National Natural Science Foundation of China(21776236,21676225)Natural Science Foundation of Hunan Province(2018JJ2384)+1 种基金the Scientific Research Foundation of Huaihua University(HHUY2017-08)Collaborative Innovation Centre of New Chemical Technologies for Environmental Benignity and Efficient Resource Utilization
