多糖/金属氧化物复合膜的阻燃抗菌性研究

火灾隐患和公共卫生安全已成为影响人类安全和健康的主要潜在问题。在未来,环保和健康的多功能材料是必然趋势。通过流延法和逐层法制备了两种具有阻燃和抗菌性能的多糖复合膜:壳聚糖/卡拉胶/CuO复合膜(P_CA/CuO/CS)、壳聚糖/卡拉胶/Fe₂O₃复合膜(P_CA/Fe2O3/CS。所制备的多糖金属氧化物复合膜具有规则的形貌,表现出较好的阻燃性和较强的抗菌性。其中,F_CA/CO/CS由于Cu²⁺与细胞内部的酶结合,阻碍细胞的新陈代谢,对金黄色葡萄球菌有更好的抑菌效果;相比F_CA/CuO/CS,F_CA/Fe2O3/CS的极限氧指数值为38%,具有较好的阻燃性能。     

溶胶-凝胶法制备Cu-ZnO-ZrO2催化剂：柠檬酸用量对催化剂性能的影响

采用溶胶-凝胶法以铜、锌、锆硝酸盐和柠檬酸为原料，改变柠檬酸用量，制备出一系列Cu-ZnO-ZrO₂催化剂。通过X射线衍射仪（XRD）、热重分析仪（TG-DTG-DTA）、H₂程序升温还原（H₂-TPR）、CO₂程序升温脱附（CO₂-TPD）、红外光谱仪（FTIR）及BET比表面积等表征手段对干凝胶及催化剂理化性能进行测试，并在催化反应活性评价装置上对催化剂的CO₂加氢合成甲醇反应活性进行评价，研究凝胶过程中Cu²⁺、Zn²⁺、Zr⁴⁺与柠檬酸结合方式对催化剂性能的影响。结果表明：改变柠檬酸用量可调控Cu²⁺、Zn²⁺、Zr⁴⁺与羧酸的配位方式，配位能力较强的Cu²⁺、Zn²⁺在凝胶制备过程中参与三维网络的构筑，而配位能力相对较弱的Zr⁴⁺游离于三维网络之外，从而差异化地调控催化剂中活性组分CuO、ZnO、ZrO₂晶粒尺寸大小。当柠檬酸的摩尔量为金属离子摩尔量的1.5倍时，催化剂中的活性成分CuO、ZnO、ZrO₂晶粒尺寸相互匹配，表现出较好的CO₂加氢合成甲醇催化性能。     

微波水热法制备氧化镁-氧化铜-氧化钙复合材料及其抗菌性能

以氯化镁、氯化铜、氯化钙为原料,十六烷基三甲基溴化铵（CTAB）为分散剂,采用微波水热法合成了氧化镁-氧化铜-氧化钙复合材料;通过X射线衍射（XRD）、扫描电镜（SEM）、氮吸附（BET）等表征手段对样品进行了结构表征;利用最小抑菌浓度（MIC）和菌落计数法对样品的抗菌性能进行了研究。实验结果表明：氧化镁-氧化铜-氧化钙复合物具有纳米片状结构,制备的MgO_0.7CuO_0.1CaO_0.2比表面积为66.789 m²/g,平均孔径为54.117 nm,孔容为0.904 cm³/（g·nm）;MgO_0.7CuO_0.1CaO_0.2在质量浓度为500 μg/mL条件下展现出良好的抗菌性能,在质量浓度为600 μg/mL以上时抑菌率达到99.9%以上。     

氧化铈-二氧化硅介孔材料制备及对铜离子的吸附性能

采用共沉淀法和沉淀浸渍法制备了纳米氧化铈-二氧化硅（CeO₂-SiO₂）介孔材料吸附剂,主要考察了其对水中铜离子（Cu²⁺）的吸附行为。通过X射线衍射（XRD）、扫描电镜（SEM）和氮吸附（BET）等手段对合成的介孔材料进行了性能表征,并通过静态吸附实验分析了溶液pH、溶液初始金属离子质量浓度、吸附剂用量、吸附时间等条件对介孔材料吸附Cu²⁺性能的影响。结果表明：共沉淀法制备的纳米CeO₂-SiO₂介孔材料对Cu²⁺的去除效果较沉淀浸渍法要好;当溶液pH=7.0时CeO₂-SiO₂介孔材料对Cu²⁺的吸附效果最好,20 min时基本达到吸附平衡;溶液初始Cu²⁺浓度增大Cu²⁺去除率降低,Cu²⁺累计吸附量增大;随着吸附剂用量增加Cu²⁺去除率增大,当CeO₂-SiO₂吸附剂用量为0.15 g/L时对Cu²⁺的去除率趋于稳定;CeO₂-SiO₂吸附剂对不同金属离子吸附性能由大到小的顺序为Cu²⁺、Fe²⁺、Mn²⁺,该吸附过程均符合准二级动力学模型。     

Al2O3/ACF复合电极材料的制备及性能表征

以H₃PO₄预处理后的活性炭纤维(ACF)毡为原料,采用浸渍煅烧法制备Al₂O₃/ACF复合电极材料;通过扫描电镜(SEM)、比表面积及孔径分析仪(BET)、X射线衍射(XRD)、X射线光电子能谱(XPS)、傅里叶红外光谱分析仪(FTIR)对负载Al₂O₃前后活性炭纤维的微观结构与电化学性能进行表征,利用自制的电吸附装置对NaCl模拟废水进行电吸附性能测试。结果表明,采用浸渍煅烧法成功制备了Al₂O₃/ACF复合电极材料,Al₂O₃/ACF复合体表面及孔道中有絮状或颗粒状的Al₂O₃存在,比表面积从1244.37 m²·g^-1降为974.59 m²·g^-1;同时,Al元素含量为1.06%,Al₂O₃以无晶相无定形态存在于纤维表面;Al₂O₃/ACF表面形成一些Al O键的官能团,其比电容比ACF提高76.5%。负载Al₂O₃后的ACF电极材料电吸附性能增强,除盐效率较ACF原样电极提升了2.3倍,且电极具有可再生性。Al₂O₃/ACF复合材料可以作为电极材料用于去除废水中的无机盐离子。     

炭化活化条件对Cu/AC表面Cu价态及其催化降解苯酚的影响

采用前体浸渍法研制了生物质基载铜活性炭催化剂（Cu/AC），利用N₂-吸附脱附、X射线光电子能谱等技术对Cu/AC性质进行了表征，在固定床反应器中研究了不同炭化活化条件所得Cu/AC催化湿式氧化降解苯酚性能。结果表明：Cu/AC表面Cu物种以Cu²⁺和（Cu⁺+Cu⁰）共存。随着制备Cu/AC炭化温度的升高，炭化过程中产生更多的挥发分，促进Cu²⁺还原为Cu⁺和Cu⁰，（Cu⁺+Cu⁰）含量增大，Cu/AC降解苯酚催化活性逐渐升高；随着炭化时间延长，（Cu⁺+Cu⁰）含量下降，Cu₂O、CuO较好地并入载体使晶格氧含量增加，催化活性先升高后下降；随着活化温度升高和活化时间延长，Cu/AC比表面积达到1096.1m²/g并有大量微孔生成，大量含氧官能团分解将炭化过程中还原生成的（Cu⁺+Cu⁰）氧化为Cu²⁺，晶格氧含量增加，催化活性随着活化温度的升高而升高，随着活化时间的延长先升高后下降。催化湿式氧化降解苯酚过程中，Cu/AC具有良好的稳定性和低的Cu离子浸出浓度。Cu/AC的最优制备条件为炭化温度800℃，炭化时间2h，活化温度880℃，活化时间为2h，所得Cu/AC在反应8.5h时实现98.5%的苯酚转化率和91.1%的COD转化率。     

Cu2+和Co2+促进芬顿氧化处理垃圾渗滤液的研究

通过在传统芬顿体系中加入Cu²⁺、Co²⁺,研究Cu²⁺/Co²⁺/Fe²⁺/H₂O₂、Cu²⁺/Fe²⁺/H₂O₂、Co²⁺/Fe²⁺/H₂O₂和Fe²⁺/H₂O₂四种芬顿体系对垃圾渗滤液的处理效果,发现当初始pH分别为2、3、4、5、6时,各体系去除CODCr的效果排序为Cu²⁺/Co²⁺/Fe²⁺/H₂O₂>Cu²⁺/Fe²⁺/H₂O₂>Co²⁺/Fe^2...     

海藻酸钠/二氧化硅杂化微球结构与吸附性能

利用海藻酸钠（SA）和正硅酸四乙酯（TEOS）为原料,并利用醇解TEOS提供二氧化硅（SiO₂）源与SA分子结构上的羟基（-OH）进行反应,制备一系列不同组分的杂化微球。采用旋转流变仪（DHR）、傅里叶变换红外光谱（FTIR）、X-射线光谱（XRD）、热重分析仪（TG）、扫描电子显微镜（SEM）和氮气吸附-脱附方法（BET）对杂化溶液的流变性能以及杂化微球的化学结构、结晶能力、热分解能力、微球形貌、比表面积和孔径进行分析,并研究了其对亚甲基蓝（MB）和重金属铜（Cu²⁺）的吸附能力。结果表明：SA/SiO₂杂化溶液体系黏度下降,在初始剪切速率25s^-1时杂化溶液黏度比SA黏度低了2.2Pa·s;FTIR图说明SA中羟基与TEOS中的硅氧键反应生成硅氧碳键,TEOS与SA发生化学反应;杂化微球结晶曲线中CA结晶特征峰强度降低,同时出现SiO₂的结晶特征峰;杂化微球分解温度由250℃提升到310℃,热分解温度提高;BET测试得到海藻酸钙（CA）比表面积为7.254m²/g,孔径为19.65nm,CA/SiO₂杂化微球的比表面积为49.151m²/g,孔径为21.75nm,杂化微球比表面积提高,孔径类型为介孔;当MB初始浓度为100mg/L时,SA/SiO₂杂化微球去除率达到87.09%;当Cu²⁺初始浓度为2.5g/L时,SA/SiO₂杂化微球去除率达到86.8%。     

CeO2的形貌对CuO/CeO2催化剂CO2加氢制甲醇性能的影响

采用水热法制备CeO₂纳米颗粒（W-CeO₂）、CeO₂纳米片（S-CeO₂）、CeO₂纳米棒（B-CeO₂）及CeO₂纳米八面体（O-CeO₂）,用浸渍法负载相同质量分数的铜形成CuO/CeO₂催化剂。通过扫描电镜（SEM）、高分辨透射电子显微镜（TEM）、X射线衍射（XRD）、拉曼光谱（Raman）、自动吸附分析仪（BET）、H₂程序升温还原（H₂-TPR）、N₂O滴定等表征技术对催化剂进行表征,并在可控温控压的固定床石英管反应器中对催化剂的催化性能进行评价。研究了不同形貌CuO/CeO₂催化剂对CO₂加氢制备甲醇的影响;结果表明,CuO/CeO₂催化剂的催化活性存在明显的形貌依赖性,催化剂的暴露晶面、比表面积、表面碱性位点、表面氧缺陷的差异均会对CO₂转化率、甲醇选择性和产率产生影响。其中,不同形貌CeO₂优先暴露晶面的活性顺序为S-CeO₂（{100}+{110}）>W-CeO₂{100}>B-CeO₂{111}≈O-CeO₂{111},暴露晶面活性越高,催化剂表面氧缺陷越多,CuO-CeO₂间相互作用越强,则催化活性越好。当为CuO/S-CeO₂时,催化剂表面中碱性位点最多,催化剂比表面积为88.8m²/g,铜分散度为19.2%,CO₂转化率为6.56%,甲醇选择性和收率为96.3%和0.063g/(g_cat·h),催化活性最好,由活性评价试验得转化率由高到低依次为S-CeO₂>B-CeO₂>W-CeO₂>O-CeO₂,可知CeO₂形貌差异会决定CuO/CeO₂催化剂的物化性能和催化活性,从而提升对不同形貌CuO/CeO₂催化剂催化CO₂加氢制甲醇的基础认识。     

CrO x /Ti-Al2O3催化剂结构及其催化丙烷脱氢性能

以模板法制备的Ti改性Al₂O₃为载体制备了CrO _x /nTi-Al₂O₃催化剂,考察了Ti含量对催化剂的结构及其催化丙烷脱氢性能的影响。采用X射线衍射（XRD）、N₂吸附-脱附、透射电子显微镜（TEM）、傅里叶变换红外光谱（FTIR）、拉曼光谱、X射线光电子能谱（XPS）、氨气程序升温脱附（NH₃-TPD）、吡啶红外吸附（Py-IR）等方法对催化剂的结构进行了表征。结果表明,CrO _x /nTi-Al₂O₃催化剂具有均匀的泡沫状介孔结构并含有少量微孔,表面积在180~195m²/g;铬主要以Cr⁶⁺和Cr³⁺形式存在,其中Cr⁶⁺主要以单铬酸盐和双铬酸盐形式存在,Cr³⁺以α-Cr₂O₃晶体和高分散Cr₂O₃形式存在,Ti的加入降低了催化剂表面Cr⁶⁺含量,增加了孔道内高分散Cr³⁺含量;Ti的加入降低了弱酸的强度,生成了少量中强酸,并使催化剂中B酸和L酸中心数量明显减少。少量的Ti（0.5%~1.0%TiO₂,质量分数）可明显提高丙烷转化率和丙烯收率,但过多的Ti（>2%TiO₂）则明显降低丙烯选择性而使丙烯收率降低。CrO _x /nTi-Al₂O₃催化剂表面Cr⁶⁺物种可催化丙烷氧化脱氢,本身还原成Cr³⁺后继续催化丙烷直接脱氢,孔道内部的高分散Cr³⁺可催化丙烷直接脱氢反应,二者结合使催化剂保持了较高的催化活性和较好的稳定性。     

γ-氧化铁/山梨酸/银-二氧化钛的制备及抗菌性能

采用溶胶凝胶-水热法制备了γ-氧化铁/山梨酸/银-二氧化钛催化剂。以可见光驱动下对大肠埃希氏菌的对数去除率为评价指标,获得了催化剂的最佳制备参数：n（银）/n（钛）=0.03、n（山梨酸）/n（钛）=0.2、水热温度为160 ℃、水热时间为12 h。利用X射线衍射（XRD）、X射线光电子能谱（XPS）、BET法比表面积（BET）、高倍扫描电镜（FESEM）等表征方法对其结构、表面特性、光学性能和磁性性能进行分析。催化剂的物化性能优异：构成为纯锐钛矿二氧化钛、顺磁性γ-氧化铁和单质银,山梨酸以单齿方式与二氧化钛结合;外观为类球形构成的比表面积为125.726 m²/g的介孔结构;可响应200~800 nm全波段光;是饱和磁化强度为10.478 A·m²/kg的超顺磁材料。自由基淬灭试验确定活性氧（ROS）影响抗菌活性的顺序从大到小依次为·OH、O₂^·-、h⁺。自由基、游离银离子和山梨酸构成协同抗菌体系,使催化剂在可见光和黑暗条件下均具有良好的抗菌活性,对数去除率分别为5.91和2.54。     

Efficient destruction of bacteria with Ti(IV) and antibacterial ions in co-substituted hydroxyapatite films

Hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂: HAP) was co-substituted with Ti(IV) and antibacterial ions (Ag⁺, Cu²⁺ or Zn²⁺) (HAPTiM), by coprecipitation and ion-exchange methods. Both HAPTiAg and HAPTiCu coated on porous spumous nickel film showed high efficiency for killing Escherichia coli and Staphylococcus aureus in the dark and under weak UVA irradiation, respectively. Moreover, their bactericidal activities were much higher than that of P25-TiO₂ film. The studies of ESR revealed that not only O₂⁻ was formed on HAPTiM, HAPTi, HAP and P25-TiO₂ films under weak UVA irradiation, but also at ambient temperature without light O₂⁻ was generated on HAPTiCu, HAPTiAg, and HAPTi. The redox couples of Cu⁰/Cu²⁺ and Ag⁰/Ag⁺ in the structure of HAPTiCu (Ag) caused the transfer of electron leading to the O₂⁻ generation under the above conditions. The higher bactericidal activities of HAPTiM were due to the synergy of the oxidation role of the O₂⁻ and the bacteriostatic action of antibacterial ions. The process of the damage of the cell wall and the cell membrane was directly observed by TEM, and further confirmed by the determination of potassium ion (K⁺) leakage from the killed bacteria.     

Palladium-substituted lanthanum cuprates: application to automotive exhaust purification

A series of palladium-substituted La₂CuO₄, corresponding to the formula La₂Cu_{1 −x}Pd_xO₄ (x = 0−0.2) were prepared by metal nitrate decomposition in a polyacrylamide gel. This method allows an easy incorporation of palladium in the mixed-oxides, which are formed at moderate temperature with rather high specific areas (13–17 m²/g). The partial substitution of copper for palladium allows a strong improvement of the three-way catalytic activity, in particular for NO reduction. The light-off temperatures for the conversions of CO, NO and C₃H₆ decreased markedly when increasing the palladium content, the activity of catalysts La₂Cu_0.9Pd_0.1O₄ and La₂Cu_0.8Pd_0.2O₄ being comparable to that of a Pt-Rh/CeO₂–Al₂O₃ catalyst for NO reduction, and higher for CO and C₃H₆ oxidation.

All the La₂Cu_{1 − x} Pd_xO₄ catalysts are activated under reacting conditions. This activation corresponds to the destruction of the mixed-oxide structure, with formation of reduced Pd⁰ ions atomically dispersed, surrounded by Cu⁺ and Cu²⁺ species on a lanthanum oxycarbonate matrix. This high dispersion state of the two transition metals in various oxidation states is supposed to originate from the initial La₂Cu_{1 −x}Pd_xO₄ structure.     

Active sites of Cu-ZSM-5 for the decomposition of acrylonitrile

The catalytic decomposition of acrylonitrile (AN) over Cu-ZSM-5 prepared with various Cu loadings was investigated. AN conversion, during which the nitrogen atoms in AN were mainly converted to N₂, increased as Cu loading increased. N₂ selectivities as high as 90–95% were attained. X-ray diffraction measurements (XRD) and temperature-programmed reduction by H₂ (H₂-TPR) showed the existence of bulk CuO in Cu-ZSM-5 with a Cu loading of 6.4 wt% and the existence of highly dispersed CuO in Cu-ZSM-5 with a Cu loading of 3.3 wt%. Electron spin resonance measurements revealed that Cu-ZSM-5 contains three forms of isolated Cu²⁺ ions (square-planar, square-pyramidal, and distorted square-pyramidal). The H₂-TPR results suggested that in Cu-ZSM-5 with a Cu loading of 2.9 wt% and below, Cu⁺ existed even after oxidizing pretreatment. The activity of AN decomposition over Cu/SiO₂ suggested that CuO could form N₂, but, independent of the CuO dispersion, nitrogen oxides (NO_x) were formed above 350 °C. Cu⁺ and the square-pyramidal and distorted square-pyramidal forms of Cu²⁺ showed low activity for AN decomposition. Temperature-programmed desorption of NH₃ suggested that N₂ formation from NH₃ proceeded on Cu²⁺, resulting in the formation of Cu⁺. The Cu⁺ ions were oxidized to Cu²⁺ at around 300 °C. Thus, high N₂ selectivity over Cu-ZSM-5 with a wide range of temperature was probably attained by the reaction over the square-planar Cu²⁺, which can be reversibly reduced and oxidized.     

One-electron reducibility of isolated copper oxide on alumina for selective NO–CO reaction

The H₂-TPR (temperature-programmed reduction) study was performed for supported copper oxide catalysts with low loading (0.5 wt% as copper). Among the various kinds of support materials (γ-Al₂O₃, TiO₂, ZrO₂, SiO₂, ZSM-5), alumina-supported copper oxide indicated a one-electron reduction behavior of Cu²⁺ into Cu⁺ ions in the presence of H₂. The reduction of the isolated Cu²⁺ species in a tetragonally distorted octahedral symmetry into the low coordinated Cu⁺ ions was identified by means of X-ray absorption spectroscopy (XANES and EXAFS). The isolated Cu⁺ ions hosted by γ-Al₂O₃ surface were prevented from further reduction into metallic Cu⁰ state under reducing condition with H₂ at 773 K. Less dispersed supported copper oxide species were easily reduced to Cu⁰ metal particles with H₂ at 573 K regardless of the kinds of support materials. It is suggested that the one-electron redox behavior of the isolated copper oxide species over γ-Al₂O₃ promotes the catalytic reduction of NO with CO in the presence of oxygen on the basis of redox-type mechanism between Cu²⁺ and Cu⁺ in atomically dispersed state.     

铜铈改性镁铝尖晶石作为助催化剂同时脱除FCC烟气中的SOx,Nox

为降低催化裂化烟气中的SO_x、No_x,采用溶胶凝胶法合成了Mg-Al尖晶石,并通过共胶法进行金属氧化物改性制备得到催化裂化烟气脱硫脱硝助催化剂。在小型固定床反应装置上考察了铜铈改性以及烟气中O₂含量对尖晶石脱硫脱硝性能的影响,并在小型提升管装置上考察了铜铈复合改性后尖晶石同时脱硫脱硝的性能。结果表明：经铜铈复合改性后的尖晶石脱硫活性最高,40min内仍能保持90.67%的SO₂脱除率;含铜尖晶石的脱硝性能最优,450℃后NO转化率达100%。烟气中O₂含量对脱硫有利而对脱硝不利,当O₂含量过高时,NO不能有效脱除。原位红外漫反射分析表明：含铜尖晶石良好的脱硝性能是因为其含有的Cu⁺对CO优异的吸附性能,O₂的影响在于其与CO的反应,导致CO消耗。提升管装置评价实验结果表明：主风量为0.6m³/h时,CuCe-MgAl脱硫效率为59.96%,脱硝效率为87.63%。当主风量为0.8m³/h时,脱硫效果提升至74.50%而失去了脱硝功能。     

Surface and bulk properties of Cu–ZSM-5 and Cu/Al2O3 solids during redox treatments. Correlation with the selective reduction of nitric oxide by hydrocarbons

This paper deals with the redox properties of Cu ions implanted in ZSM-5 and supported on Al₂O₃, catalysts active in the selective reduction of NO by hydrocarbons such as propane. Data on the reducibility of the Cu systems in various atmospheres (vacuum, CO, H₂, O₂) and on their DeNO_x activity are presented. The methods used to obtain informations on the surface and bulk transformations (and their link with catalytic behaviour) are complementary: UV–visible diffuse reflectance spectroscopy being useful to detect the presence of Cu²⁺ and Cu⁰, while Cu⁺ is detected indirectly by the analysis of the IR spectrum of CO bound selectively to this cation.

The main contributions to the previous knowledge are the following: it is possible to distinguish CO bound to isolated and non-isolated Cu⁺ ions; the isolated Cu²⁺ ions are reducible under vacuum without participation of organic impurities; the more active solids for the NO reduction into N₂ are characterized by the presence of isolated Cuⁿ⁺ ions beside the additional influence of the zeolitic framework; after the formation of Cu⁺ ions the redox cycles are reversible but, after the formation of Cu⁰, the reversibility or irreversibility of the redox cycles and the restoration of the SCR activity are function of the copper content; the activity decreases after agglomeration into bulk oxides; there is no formation of bulk CuO during the reaction and, with reducing and moderate oxidizing mixtures, part of the copper remains as cuprous ions.     

Fabrication of Poly（y-glutamic acid）-coated Fe3O4 Magnetic Nanoparticles and Their Application in Heavy Metal Removal

In this study, poly（y-glutamic acid）-coated Fe3O4 magnetic nanoparticles （y-PGA/Fe304 MNPs） were successfully fabricated using the co-precipitation method. Fe3O4 MNPs were also prepared for comparison. The av erage size and specific surface area results reveal that 7-PGA/Fe304 MNPs （52.4 nm, 88.41 m2.g-1） have smaller particle size and larger specific surface area_ than Fe3O4 MNPs （62.0 nm, 76.83 mLg-1）. The y-PGA/Fe3O4 MNPs