新型Pt基整体式催化剂的结构与催化性能

以堇青石蜂窝陶瓷(CHC)为载体,采用化学镀法制备Pt基整体式催化剂Pt-CHC,研究Pt-CHC催化剂在甲醛催化燃烧中的催化性能;对Pt-CHC催化剂在不同的甲醛初始浓度范围、较宽的空速范围与不同的进样相对湿度条件下进行活性测试,并进行扫描电镜和X射线能量色散谱表征。结果表明:Pt-CHC催化剂在Pt负载量较小(质量分数为0.24%)时,甲醛可在100℃时基本转化完全;活性组分Pt在蜂窝陶瓷载体表面选择性富集,Pt颗粒在催化剂中通孔道内部与孔口处均能基本维持均匀分布,颗粒粒径小于100 nm。     

Ce-Ni-Mn-O复合氧化物催化剂催化燃烧苯的性能研究

以堇青石蜂窝陶瓷为载体,以Ce(NO3)2、Ni(NO3)2和Mn(NO3)2为原料,采用柠檬酸浸渍法制备了负载型Ce-Ni-Mn-O复合氧化物催化剂,考察了Ce、Ni与Mn摩尔比、焙烧温度和焙烧时间对催化燃烧苯的性能影响,并采用比表面积分析仪(BET)、X射线衍射仪(XRD)、扫描电镜(SEM)对催化剂进行表征。实验结果表明,在系列催化剂中,n(Ce)/n(Ni)/n(Mn)=1∶0.5∶0.5,经500℃焙烧7h的催化剂表现出最佳的催化燃烧苯的活性,在300℃及体积空速为15000h-1条件下,即可促使浓度为4.8g/m3的苯催化转化率达到91.8%。     

堇青石蜂窝陶瓷载体酸处理对整体式La0.8Sr0.2MnO3催化剂催化甲苯燃烧性能的影响

整体式催化剂是一种常用的催化剂,蜂窝陶瓷载体是其重要组成部分。酸处理可以改进其结构上的不足。使用不同质量分数、种类的酸溶液对堇青石蜂窝陶瓷载体进行了预处理,考察了酸处理对整体式催化剂的基本性质及甲苯催化活性的影响,并采用XRD、BET等表征手段进行分析。结果表明,蜂窝陶瓷载体经质量分数为30%硝酸溶液处理后可达最佳效果,负载率提高48%以上,比表面积扩大20倍以上,由其制得的催化剂催化甲苯燃烧的起燃温度为219℃,降低了19℃,完全转化温度为281℃。表征结果说明酸洗过程未改变载体组成,而是使载体比表面积增加20倍以上,从而提高了整体催化剂的催化活性。     

1,2 -二氯乙烷在担载铈钛复合氧化物的蜂窝陶瓷催化净化——催化组分颗粒大小的影响

采用溶胶-凝胶法制备担载 TiO2 和 CeTiOx 复合氧化物涂层的堇青石蜂窝陶瓷整体式催化剂,并考察 1,2-二氯乙烷(DCE)在上述催化剂上的催化效果。结果表明:TiO2 和 CeTiOx 复合氧化物涂层材料对DCE 的催化燃烧均具有很好的催化活性, 前者在 400 ℃时,DCE 的转化率为 93.1%,后者已达 98.5%,可见,CeTiOx 可以更有效地催化燃烧处理 DCE。譬如,在 300 ℃时,在 CeTiOx 涂覆的催化剂上 DCE 的转化率为 85.6%。但随着催化剂处理温度的升高,CeTiOx 催化活性组分的颗粒变大,导致 CeTiOx 蜂窝陶瓷催化剂对于 DCE 的催化活性降低。     

V2O5/CNFs/蜂窝状堇青石催化剂的结构控制及其烟气脱硝性能

采用化学气相沉积法,在涂层Al2O3的蜂窝状堇青石表面生长纳米碳纤维(CNFs),通过负载V2O5催化剂,制成低温蜂窝状脱硝催化剂.采用SEM、TEM、XRD和XPS等分析方法,对所制催化剂的物化性质及其脱硝性能进行了分析.研究结果表明,当CNFs在堇青石表面的生长厚度为0.74μm时,所制CNFs/堇青石载体的压缩强度达34.46 MPa;在150~250℃范围内,V2O5/CNFs/蜂窝状堇青石催化剂表现出较高的低温脱除NO活性,其中当CNFs的生长量为12.5%、V2O5担载量为1%时,在250℃下NO的转化率达95%左右.     

堇青石质蜂窝陶瓷专利技术分析

堇青石因其自身的优越性能在制备蜂窝陶瓷方面具有广泛的用途,该文通过在VEN数据库中检索、统计、分析国内外堇青石质蜂窝陶瓷的专利申请文献,从性能参数研究方面收集和梳理堇青石质蜂窝陶瓷的重点专利技术,分析影响堇青石质蜂窝陶瓷性能的参数及其关系,包括膨胀系数、孔隙率、孔径分布、强度、弹性模量、压降和可制造性等,对制造具有可接受的物理性质与可加工性的组合的过滤器以及对相关专利申请的理解与判定具有积极意义。     

堇青石质多孔陶瓷的制备与应用现状

概述了堇青石质多孔陶瓷的特点及研究现状,系统介绍了堇青石质多孔陶瓷在催化剂载体材料、过滤分离材料、耐火材料以及电子器件材料等方面的最新研究进展,总结了堇青石质多孔陶瓷的制备方法,并展望了堇青石质多孔陶瓷研究的发展趋势。     

堇青石负载稀土铈基催化剂催化燃烧苯的性能研究

以堇青石蜂窝陶瓷为载体,以过渡金属Mn(NO3)2和稀土金属Ce(NO3)2·6H2O盐为原料,采用柠檬酸浸渍法制备负载型MnCeOx混合氧化物催化剂,考察Mn与Ce的摩尔比、焙烧温度与时间以及柠檬酸用量对催化燃烧苯性能的影响,应用正交实验设计方案优化最佳制备工艺参数,并采用X射线衍射仪(XRD)、H2-TPR和扫描电镜(SEM)对催化剂进行表征与分析。实验结果表明n(Mn)∶n(Ce)=19∶21,焙烧时间为7h,n(Mn+)∶n(柠檬酸)=6∶1的催化剂表现出最佳的催化活性,在300℃及体积空速为20000h-1条件下,催化燃烧浓度为1.5×10-3的苯,催化转化率可达99.1%。     

煤矸石制备堇青石蜂窝陶瓷载体的研究

以潞安煤矸石为主要原料,辅以少量工业菱镁矿、滑石和成型助剂,制备出堇青石蜂窝陶瓷。用X-射线衍射仪(XRD)和扫描电镜(SEM)分别表征了蜂窝陶瓷的物相组成和显微结构。结果表明样品由片状晶相和大量微孔组成,晶相主要为堇青石。考察了各影响因素对蜂窝陶瓷性能的影响,实验表明当总含液量约为30%、陈腐时间24h,煅烧温度1200～1300℃下保温4～6h时,蜂窝陶瓷载体的成型效果及性能较优。     

Ni-Pd纳米涂层整体式催化剂加氢性能研究

采用浸涂法将自制的介孔空心SiO2纳米粉体涂覆到堇青石基体上,然后采用微波法负载活性组分Pd和助剂Ni制备了纳米涂层整体式加氢催化剂,并考察空速、涂层增重、Ni助剂添加量等因素对其乙炔选择性加氢催化性能的影响。结果表明:经过涂覆后的堇青石整体式催化剂加氢性能与未涂覆时相比有了显著提高,且添加适量的助剂Ni有助于催化性能的进一步改进。在反应温度为54℃、压力为0.1 MPa、空速为3 800 h-1的条件下,使用涂层增重质量分数为6%、Ni与Pd物质的量比为4∶1的催化剂,当乙炔接近完全转化时,乙烯选择性能够到达40.9%。     

Complete oxidation of formaldehyde at ambient temperature over supported Pt/Fe2O3 catalysts prepared by colloid-deposition method

The catalytic properties of iron oxide supported platinum catalysts (Pt/Fe(2)O(3)), prepared by a colloid deposition route, were investigated for the complete oxidation of formaldehyde. It is found that all the Pt/Fe(2)O(3) catalysts calcined at different temperatures (200-500°C) were active for the oxidation of formaldehyde. Among them, the catalysts calcined at lower temperatures (i.e., 200 and 300°C) exhibited relatively high catalytic activity and stability, which could completely oxidize HCHO even at room temperature. Based on a variety of physical-chemical characterization results, it is proposed that the presence of suitable interaction between Pt particles and iron oxide supports, which is mainly in the form of Pt-O-Fe bonds, should play a positive role in determining the catalytic activity and stability of the supported Pt/Fe(2)O(3) catalysts.     

Synthesis of SnO(Sn)/Ni foam monolithic catalysts and their catalytic activity

以泡沫镍为载体制备一系列活性组分为SnO和Sn的整体催化剂,测定了催化剂对邻苯二甲酸二(2-乙基己)酯(DOP)合成反应的催化活性,研究了电镀电流密度、电镀温度和焙烧处理对催化性能的影响,以及整体催化剂的寿命和失活的原因. 结果表明,所制备的SnO(Sn)/泡沫镍整体催化剂对DOP的合成有很好的催化活性和选择性.用整体催化剂Sn/Ni-3(300)催化DOP的合成反应,在1h的反应时间内邻苯二甲酸酐的转化率达到96.75%;反应平衡时合成的产物中DOP的选择性达到97%以上.SnO(Sn)/泡沫镍整体催化剂使用后很容易从反应体系中分离,不需要任何处理即可重复使用多次.     

钙钛矿型La0.9Sr0.1NiO3催化剂的合成条件及其可见光催化活性的研究

采用溶胶-凝胶法制备了钙钛矿型La0.9Sr0.1NiO3复合氧化物光催化剂,通过TG-DTA、XRD、可见光催化性能等对合成产物的热分解过程、物相结构和可见光催化活性进行了研究;采用单因素实验探究了合成工艺条件(柠檬酸用量、pH值、煅烧温度、煅烧时间)对合成产物的物相结构和可见光催化性能的影响。结果表明,在柠檬酸用量与金属离子的总量比为1∶1,pH=1.5,400℃预处理4h,700℃煅烧4h时可制备出单一相的六方晶系的La0.9-Sr0.1NiO3晶体;在500 W氙灯的照射下,当La0.9Sr0.1NiO3催化剂用量为1.20g/500mL时,在180min内对13.2mg/L的甲基橙溶液的脱色率达到62.1%。     

Studies on the dehydration of glycerol over niobium catalysts

The dehydration of glycerol over nanosize niobium catalysts was conducted in a stainless steel autoclave reactor. The catalysts were prepared by the calcination of niobium oxalate between 200 and 700 degrees C. Catalysts were characterized by N2 Physisorption, XRD and TPD of ammonia to investigate the effect of the calcination temperature and water on catalytic performance, catalysts' structures and acidity. Acrolein was mainly produced about 51-71% with useful by-products such as acetaldehyde and methanol. Amorphous Nb2O5 catalysts calcined at 200-400 degrees C significantly showed higher conversion of glycerol than the crystallized Nb2O5 catalyst calcined at 500-700 degrees C. Also the conversion of glycerol and selectivity of acrolein was increased with increasing the acidity of catalyst, which can be controlled by calcination temperature.     

Fe3O4纳米粒子作为催化剂和致孔剂制备高比表面积块体石墨化炭

报道了一种以Fe3O4纳米晶粒为催化剂和致孔剂制备具有高比表面积块体石墨化炭的方法.首先采用共沉淀法合成粒径＜10nm的Fe3O4纳米颗粒,然后将其均匀分散到以2,4-二羟基苯甲酸(D)、甲醛(F)为原料,无水Na2 CO3为催化剂形成的聚合物(DF)中,通过溶胶-凝胶过程和炭化过程得到掺杂Fe的石墨化炭.最后经过酸洗,得到纯的高比表面积块体石墨化炭.随炭化温度的升高(700℃～900℃),样品的石墨化程度增加.在800℃炭化,样品已具有明显的石墨化结构,且比表面积较大.     

La1-xSrxMnAl11O19-δ催化剂的甲烷燃烧性能研究

采用反相微乳液-共沉淀法制备了一系列以La、Sr作为镜面阳离子、锰离子作为活性组分的六铝酸盐催化剂La1-xSrxMnAl11O19-δ(x=0.2、0.4、0.5、0.6、0.8)。利用X射线衍射、比表面积分析等分析方法及甲烷燃烧对催化剂的结构和性质进行了考察,主要考察了不同含量的La和Sr离子的掺杂量对催化剂结构及对甲烷催化燃烧活性的影响。结果表明,La和Sr同时作为镜面阳离子,不但可以形成完整的六铝酸盐,而且所制备的催化剂具有较高的催化活性。不同含量的La和Sr离子掺杂对于催化剂的特性有较大影响。当x=0.5时,所制备的催化剂La0.5-Sr0.5MnAl11O19-δ具有较高的催化活性,起燃温度T10%=502℃,至683℃甲烷完全转化。催化剂在低转化率下的宏观动力学实验结果表明,甲烷催化燃烧在La1-xSrxMnAl11O19-δ催化剂上为一级动力学反应,反应速率受催化剂固有性质控制。     

Decolorization of KN-R catalyzed by Fe-containing Y and ZSM-5 zeolites

Decolorization of an anthraquinone dye, Reactive Brilliant Blue KN-R by hydrogen peroxide was examined using Fe-containing Y and ZSM-5 zeolites as heterogeneous catalysts. Catalysts were prepared by ion-exchange and coprecipitation methods, and calcined at different temperatures. The surface morphologies, crystalline phases, and chemical-state of the catalysts were characterized by scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Influences of reaction conditions, such as dye concentration, catalyst dosage and solution pH, were evaluated and the relations between catalytic capacity and surface microstructures were discussed. The results showed that Fe-containing Y and ZSM-5 zeolites generally exhibited similar or better catalytic efficiency compared with homogeneous Fenton reagent, with Fe-containing ZSM-5 being more efficient. Synthesis method and calcination temperature affected catalytic efficiency and the stability of catalysts. Fe-containing ZSM-5, which was prepared by coprecipitation and calcined at 450 degrees C, displayed the greatest decolorization capacity. Under the conditions of initial pH 2.5, 30.0 mmol/L H(2)O(2) and 4.0 g/L catalyst, 250 mg/L KN-R could be decolorized over 90% within 20 min.     

Ti-Zr-V-O复合催化材料的制备及其选择性催化还原NO

采用溶胶凝胶法制备了Ti-Zr-V-O一体化脱硝复合催化材料,研究了锆掺杂对钛钒复合催化材料脱硝活性的影响,采用X 射线衍射（XRD）、扫描电镜（SEM）、能谱分析（EDS）、傅里叶红外光谱（FT-IR）及N₂物理吸附（BET法）等测试手段,分别考察了锆掺杂对钛钒复合氧化物晶型、结晶形貌、组成、官能团结构及比表面积的影响. 实验结果表明,锆掺杂可以稳定锐钛矿晶型,细化晶粒、抑制晶体生长,改变催化剂的结晶形貌,增强固体酸性,从而优化Ti-Zr-V-O复合催化剂的催化性能. 在Ti-Zr-V-O/ATS 陶瓷颗粒整装催化剂存在下,以NH₃为还原剂进行NO的选择性催化还原脱除,锆掺杂明显拓宽了催化活性温度窗口,往高温区偏移100℃;反应温度为300℃时,NO转化率提高了17.3%.     

In-situ growth of large-area monolithic Fe_2O_3/TiO_2 catalysts on flexible Ti mesh for CO oxidation

In this study, we reported the in-situ fabrication of a series of Fe_2O_3/TiO_2 monolithic catalysts on flexible Ti mesh via plasma electrolytic oxidation process, hydrothermal reaction and chemical bath deposition(CBD) method. The morphology tailoring of Fe_2O_3 nanostructures finds that Fe_2O_3 nanosheets supported on TiO_2 exhibit superior catalytic performance with a complete oxidation of CO at 260°C. The catalytic stability test indicates that the in-situ grown Fe_2O_3/TiO_2 catalysts own outstanding performance for continuous CO oxidation due to the strong substrate adhesion without mass loss. The microstructures and interfaces of Fe_2O_3/TiO_2 catalysts are well studied using series of characterization techniques. The in-situ preparation strategy of metal oxide catalysts in this work will open up more opportunities for the rational design of variety of monolithic catalysts used for CO oxidation, de-NOx, three-way catalysis and other related application in industry.     

CuO/CeO2 catalysts prepared with different cerium supports for CO oxidation at low temperature

The activity of a catalyst depends on the nature of its support, its active site, and its preparation method. This study aimed to employ various types of CeO₂ supports such as commercial CeO₂ and self-prepared CeO₂ for the preparation of copper catalysts. The CuO/CeO₂ catalysts were prepared using the polyol process and impregnation method. The catalysts were characterized using Brunauer–Emmett–Teller analysis, scanning electron microscopy, and X-ray analysis, and their catalytic activity for CO removal was evaluated in a microcatalytic reactor. The experimental results showed that the catalytic activity of the CuO/CeO₂ catalysts with different calcination temperatures decreased in the following order: 500 °C > 300 °C > 700 °C. Compared to the impregnation method, the polyol process generated well-dispersed metal particles over the support and showed higher CO removal efficiency with low activation energy. Compared to CuO/CeO₂ catalysts with commercial CeO₂, those with CeO₂ that was self-prepared by pyrolysis had a large pore volume and good crystal structure of CeO₂ and showed good performance. The catalytic activity for CO removal was in the following order: CuO/CeO₂-P (pyrolysis) > CuO/CeO₂-C (commercial) > CuO/CeO₂-D (deposition precipitation). CuO/CeO₂-P catalysts showed good activity even at low temperature. The CuO/CeO₂-P(300)-P-120 min catalyst was found to possess the good CO removal rate when the oxygen content was 6%, CO concentration was 500 ppm, catalyst weighed 1.0 g, pollutant gas velocity was 500 mL min⁻¹, SV was 3.7 × 10⁴ h⁻¹, and reaction temperature was 150 °C.