Catalytic degradation of chlorinated volatile organic compounds(CVOCs)over Ce-Mn-Ti composite oxide catalysts

Developing industrially moldable catalysts with harmonized redox performance and acidity is of great significance for the efficient disposal of chlorinated volatile organic compounds(CVOCs)in actual exhaust gasses.Here,commercial TiO_(2),typically used for molding catalysts,was chosen as the carrier to fabricate a series of Ce_(0.02)Mn_(0-0.24)TiO_(x) materials with different Mn doping ratios and employed for chlorobenzene(CB)destruction.The introduction of Mn remarkedly facilitated the synergistic effect of each element via the electron transfer processes:Ce^(3+)+Mn^(4+/3+)■Ce^(4+)+Mn^(3+/2+)and Mn^(4+/3+)+Ti^(4+)■Mn^(3+/2+)+Ti^(3+).These synergistic interactions in Ce_(0.02)Mn_(0.04-0.24)TiO_(x),especially Ce_(0.02)Mn_(0.16)TiO_(x),significantly elevated the active oxygen species,oxygen vacancies and redox properties,endowing the superior catalytic oxidation of CB.When the Mn doping amount increased to 0.24,a separate Mn_(3)O_(4) phase appeared,which in turn might weaken the synergistic effect.Furthermore,the acidity of Ce_(0.02)Mn_(0.04-0.24)TiO_(x) was decreased with the Mn doping,regulating the balance of redox property and acidity.Notably,Ce_(0.02)Mn_(0.16)TiO_(x) featured relatively abundant B-acid sites.Its coordinating redox ability and moderate acidity promoted the deep oxidation of CB and RCOOH-intermediates,as well as the rapid desorption of Cl species,thus obtaining sustainable reactivity.In comparison,CeTiO_(x) owned the strongest acidity,however,its poor redox property was not sufficient for the timely oxidative decomposition of the easier adsorbed CB,resulting in its rapid deactivation.This finding provides a promising strategy for the construction of efficient commercial molding catalysts to decompose the industrial-scale CVOCs.

Non-Isothermal Decomposion Kinetics of Supermolecule Compound [Eu（C10H9N2O4）（C10H8N2O4）（H2O）3]2·phen·4H2O

Europium（Ⅲ） compound with 2-oxopropionic acid salicyloyl hydrazone （C10H10N2O4, H3L） and 1,10-phenanthroline （C12H8N2, phen） has been prepared. A yellow prismatic crystal of the compound was obtained, and the molecule crystallized in the triclinic space group P-1. There are two 9-coordinated complex molecules in every structure unit, where every Eu atom is coordinated by three water molecules and two tridentate C10H10N2O4 ligands, forming two stable pentacycles. The coordination polyhedron around Eu^3＋ was described as a single cap square antiprism. In the crystal cell, there are one free 1,10-phenanthroline and four water molecules. The thermal decomposition of the compound and its kinetics were studied by non-isothermal thermogravimetry. The Kissinger＇s method and Ozawa＇s method were used to calculate the activation energy value of the first-step decomposition. The stages of the decompositions were identified by TG-DTG-DSC curve. The non-isothermal kinetic data were analyzed by means of integral and differential methods. The possible reaction mechanism and the kinetic equations were investigated by comparing the kinetic parameters.

Synthesis and Anti-tumor Evaluation of B-ring Modified Caged Xanthone Analogues of Gambogic Acid

Gambogic acid （GA, 1）, the most prominent member of Garcinia natural products, has been reported to be a promising anti-tumor agent. Previous studies have suggested that the planar B ring and the unique 4-oxa-tricyclo- [4.3.1.03.7]dec-2-one caged motif were essential for anti-tumor activity. To further explore the structure-activity relationship （SAR） of caged Garcinia xanthones, two new series of B-ring modified caged GA analogues 13a-13e and 15a-lge were synthesized utilizing a Claisen/Diel-Alder cascade reaction. Subsequently, these compounds were evaluated for their in vitro antitumor activities against A549, MCF-7, SMMC-7721 and BGC-823 cancer cell lines by MTT assay. Among them, 13b-13e exhibited micromolar inhibition against several cancer cell lines, being approximately 2-4 fold less potent in comparison to GA. SAR analysis revealed that the peripheral gem-dimethyl groups are essential for maintaining antitumor activity and substituent group on C1 position of B-ring has a significant effect on potency, while modifications at C-2, C-3 and C-4 positions are relatively tolerated. These findings will enhance our understanding of the SAR of Garcinia xanthones and lead to the development of simplified analogues as potential anti-tumor agents.

不同活性炭功能化材料富集分离痕量铅的应用性能对比

本实验用简单便利的方法将邻甲氧基苯甲酸修饰在吸附基体活性炭的表面,高效的合成了新型的功能化固相萃取材料I和II,用来富集分离液体样品中的痕量Pb(II),通过Langmuir吸附等温线模拟研究材料富集行为的表面状态,并对比二者的分子结构和结合位点,研究两种吸附剂的应用性能。分别对富集酸度、洗脱条件、动力学平衡时间等参数进行优化和选择,并在最优条件下测得未功能化的活性炭、功能化材料I和II对Pb(II)的吸附容量分别为15.36 mg·g^(-1)、48.25 mg·g^(-1)和85.72 mg·g^(-1),方法检出限分别为0.12 ng·m L^(-1)和0.09 ng·m L^(-1)。该材料可有效的应用于实际水样中Pb(II)的测定。