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Catalytic decomposition of CH_4 over Ni-Al_2O_3-SiO_2 catalysts:Influence of pretreatment conditions for the production of H_2 认领 引用 被引量：2
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作者 Jangam Ashok Gangadhara Raju +2 位作者 Padigapati Shiva Reddy Machiraju Subrahmanyam Akula Venugopal 《Journal of Natural Gas Chemistry》 2008年第2期113-119,共7页
This article reports the production of COx free hydrogen and carbon nanofibers by the catalytic decomposition of methane over Ni-Al2O3-SiO2 catalysts. The influence of reaction temperature, pretreatment temperature, a... This article reports the production of COx free hydrogen and carbon nanofibers by the catalytic decomposition of methane over Ni-Al2O3-SiO2 catalysts. The influence of reaction temperature, pretreatment temperature, and effect of reductive pretreatment on the decomposition of methane activity is investigated. The physico-chemical characteristics of fresh and deactivated samples were characterized using BET-SA, XRD, TPR, SEM/TEM, CHNS analyses and correlated with the methane decomposition results obtained. The Ni-Al-Si （4 ： 0.5 ： 1.5） catalyst reduced with hydrazine hydrate produced better H2 yields of ca. 1815 mol H2/mol Ni than the catalyst reduced with 5% H2/N2. 展开更多
关键词 in situ reduction Ni-Al2O3-SiO2 catalyst methane decomposition hydrogen production carbon nanofibers
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Tri-functional Ru catalyst drives efficient ammonia synthesis from N2 and H2O 认领 引用
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作者 Ying Hou Wei Hu +6 位作者 Qiao Zhao Yuchuan Tu Guang Yang Yi Cui Wei Liu Liang Yu Dehui Deng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2026年第7期769-775,I0018,共7页
1.Indroduction In light of the global transition toward carbon neutrality,the development of mild-condition ammonia synthesis technologies has gained significant attention as a promising solution to address the inhere... 1.Indroduction In light of the global transition toward carbon neutrality,the development of mild-condition ammonia synthesis technologies has gained significant attention as a promising solution to address the inherent limitations of the traditional Haber-Bosch approach,which remains highly energy-intensive due to the extreme operation conditions(above 350℃ and over 10 MPa)required to activate the robust N≡N bond(945 kJ mol-1).Furthermore,the process is carbon-intensive,as its primary hydrogen source is derived from hydrocarbon reforming with high carbon emissions[1,2]. 展开更多
关键词 NH3 synthesis N and H2O Tri-functional Ru-based catalyst Reversible Li battery
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Utilization of steelwork off-gases through methanol synthesis:Sulfur-induced dynamic migration of ZnOx over industrial Cu/ZnO/Al2O3 catalyst and the poisoning mechanism 认领 引用
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作者 Yukun Tian Yu Zeng +5 位作者 Ziyang Chen Hua Tong Ming Chen Zhiyong Zhong Daiqi Ye Limin Chen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2025年第12期659-673,共15页
The reduction of carbon emissions in the steel industry is a significant challenge,and utilizing CO2 from carbon intensive steel industry off-gases for methanol production is a promising strategy for decarbonizatio... The reduction of carbon emissions in the steel industry is a significant challenge,and utilizing CO2 from carbon intensive steel industry off-gases for methanol production is a promising strategy for decarbonization.However,steelwork off-gases typically contain various impurities,including H2S,which can deactivate commercial methanol synthesis catalysts,Cu/ZnO/Al2O3(CZA).Reverse water-gas shift(RWGS)reaction is the predominant side reaction in CO2 hydrogenation to methanol which can occur at ambient pressure,enabling the decouple of RWGS from methanol production at high pressure.Then,a series of activated CZA catalysts has been in-situ pretreated in 400 ppm H2S/Ar at 250℃and tested for both RWGS reaction at ambient pressure and CO2 hydrogenation to methanol at high pressure.An innovative decoupling strategy was employed to isolate the RWGS reaction from the methanol synthesis process,enabling the investigation of the evolution of active site structures and the poisoning mechanism through elemental analysis,X-ray Diffraction,X-ray Photoelectron Spectroscopy,Fourier Transform Infrared Spectroscopy,Temperature Programmed Reduction and CO2 Temperature Programmed Desorption.The results indicate that there are different dynamic migration behaviors of ZnOx in the two reaction systems,leading to different poisoning mechanisms.These interesting findings are beneficial to develop sulfur resistant and durable highly efficient catalysts for CO2 hydrogenation to methanol,promoting the carbon emission reduction in steel industry. 展开更多
关键词 Steelwork off-gases CO2hydrogenation to methanol H2S Cu/Zn O/Al2O3catalysts ZnOxmigration Deactivation and promotion mechanisms
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Novel promoting effects of cerium on the activities of NO_x reduction by NH_3 over TiO_2-SiO_2-WO_3 monolith catalysts 认领 引用 被引量：15
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作者 房志涛 林涛 +3 位作者 徐海迪 吴干学 孙萌萌 陈耀强 《Journal of Rare Earths》 SCIE EI CAS CSCD 2014年第10期952-959,共8页
A series of catalysts were prepared by doping different loadings of CeO2 over TiO2-SiO2-WO3 and used for the selective catalytic reduction of NOx by NH3. The experimental results showed that the selective catalytic re... A series of catalysts were prepared by doping different loadings of CeO2 over TiO2-SiO2-WO3 and used for the selective catalytic reduction of NOx by NH3. The experimental results showed that the selective catalytic reduction（SCR） performance and SO2-resistant ability of TiO2-SiO2-WO3 were greatly enhanced by the introduction of cerium. The catalyst containing 10% CeO2 showed the highest NO conversion in a wide temperature range and good N2 selectivity with broad operation temperature window at the gas hourly space velocity（GHSV） of 30000 h–1, which was a very promising catalyst for NOx abatement from diesel engine exhaust. The catalysts were characterized by X-ray diffraction（XRD）, scanning electron microscopy with energy dispersive X-ray spectroscopy（SEM-EDS）, N2 adsorption-desorption（BET） and X-ray photoelectron spectroscopy（XPS）. The characterization results showed that the bigger pore radius, higher surface atomic concentration and dispersion of Ce and the abundant adsorbed oxygen on the surface of catalyst contributed to the best NH3-SCR performance of CeO2/TiO2-SiO2-WO3 catalyst containing 10% CeO2. 展开更多
关键词 NH3-SCR NO cerium CeO2/TiO2-SiO2-WO3 monolith catalyst rare earths
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柴油机后处理ccSCR路线N2O排放特性研究 认领 引用
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作者 殷雪梅 李顺红 +3 位作者 吕志华 马江丽 常仕英 于飞 《内燃机学报》 EI CAS CSCD 北大核心 2026年第1期58-67,共10页
为研究柴油机后处理紧耦合选择性催化还原(ccSCR)路线的一氧化二氮(N2O)排放特性,研究了柴油机在世界统一瞬态循环(WHTC)、世界统一稳态循环(WHSC)和低负荷循环(LLC)下不同催化剂、不同尿素喷射量和电加热(EHC)对N2O排放的影响.... 为研究柴油机后处理紧耦合选择性催化还原(ccSCR)路线的一氧化二氮(N2O)排放特性,研究了柴油机在世界统一瞬态循环(WHTC)、世界统一稳态循环(WHSC)和低负荷循环(LLC)下不同催化剂、不同尿素喷射量和电加热(EHC)对N2O排放的影响.结果表明:氨泄漏催化剂(ASC)对N2O生成的分担率最大,高达50%;增加尿素喷射量利于降低ASC后NOx排放,但增加ASC后NH3和N2O排放风险.WHTC、WHSC和LLC循环下开启EHC,尿素喷射量增加,ASC后NOx排放下降、NH3和N2O排放增加;随EHC加热时间增加,ccSCR和SCR入口平均温度均提升,NOx、NH3和N2O排放降低;WHTC、WHSC和LLC循环下开启EHC,尿素喷射量增加是导致ASC后N2O排放增加的主要原因.针对带EHC的ccSCR国Ⅶ后处理路线,建议优化尿素喷射策略并搭配低N2O型ASC催化剂后处理系统,以实现降低NOx同时降低N2O排放. 展开更多
关键词 柴油机 紧耦合选择性催化还原催化剂 尿素喷射量 氨泄漏催化剂 氨气排放 一氧化二氮排放
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Selective Hydrogenation of Butyne-1,4-diol to Butane-1,4-diol over Ni/Al_2O_3-SiO_2 Catalysts 认领 引用 被引量：2
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作者 Fang Jie Zhuang Changjian +2 位作者 Meng Jipeng Cheng Lang Lu Jiangyin 《China Petroleum Processing & Petrochemical Technology》 CAS 2018年第4期20-28,共9页
Ni/Al_2O_3-SiO_2 catalysts were synthesized via one-step method employing SiO_2 as an additive for the selective hydrogenation of butyne-1,4-diol(B_3D) to butane-1,4-diol(B1D). The prepared catalysts were evaluated by... Ni/Al_2O_3-SiO_2 catalysts were synthesized via one-step method employing SiO_2 as an additive for the selective hydrogenation of butyne-1,4-diol(B_3D) to butane-1,4-diol(B1D). The prepared catalysts were evaluated by a series of characterization techniques including BET, XRD, SEM, EDX-mapping, TEM, H_2-TPR, XPS, NH_3-TPD and Py-FTIR. Compared to Ni/Al_2O_3 catalyst, the SiO_2-doped samples exhibited better B_3D conversion. SiO_2 could help to form a strong interaction between NiO with the support, which inhibited Ni agglomeration at high temperature, improved the Ni dispersion, and enhanced the hydrogenation activity. B_1D selectivity was mainly influenced by the quantity of Lewis acid sites in addition to the Ni dispersion. The catalyst with a silica loading of 6.4% demonstrated an excellent selectivity of 75.18%(by 13% higher than the contrastive Ni/Al_2O_3 catalyst), which was attributed to the larger amount of Lewis acid sites and the moderate interaction between NiO with the support, which could facilitate the nickel dispersion on a preferable surface area of 176.3 m^2/g of support. 展开更多
关键词 Ni/Al2O3-SiO2 catalysts butyne-1,4-diol butane-1,4-diol hydrogenation
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Effect of Ball-Milling Time on the Performance of Ni-Al2O3 Catalyst for 1,4-Butynediol Hydrogenation to Produce 1,4-Butenediol 认领 引用 被引量：2
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作者 Gao Xianlong Mo Wenlong +1 位作者 Ma Fengyun He Xiaoqiang 《China Petroleum Processing & Petrochemical Technology》 CAS 2020年第1期78-86,共9页
The Ni-Al2O3 catalyst was prepared by the mechanochemical method in combination with a planetary ballmilling machine.Effect of milling time on the crystal structure,the reduction characteristics and the catalytic perf... The Ni-Al2O3 catalyst was prepared by the mechanochemical method in combination with a planetary ballmilling machine.Effect of milling time on the crystal structure,the reduction characteristics and the catalytic performance of Ni-Al2O3 catalyst for hydrogenation of 1,4-butynediol to produce 1,4-butenediol were investigated.The catalysts were characterized by PSD,EDX,XRD,H2-TPR,BET,TEM,and NH3-TPD methods.Results showed that the MCt2.5 catalyst treated at a ball milling time of 2.5 h could form a smallest particle size of 191.0 nm.The evaluation experiments revealed that the activity of the prepared catalyst increased at first and then reached a constant value with the extension of ballmilling time.The BYD conversion,BED selectivity and yield on the MCt2.5 catalyst reached 35.63%,33.48%and 32.46%,respectively,which were higher than those obtained by other samples.The excellent performance of MCt2.5 sample is mainly related to the following three reasons from characterization results.Firstly,it has a smallest particle size of 191.0 nm;and then,the surface acidity(in terms of strong acids)of the catalyst was weaker than other catalysts;and eventually,the loading amount(23.84%)of the active component Ni exceeded the theoretical value(20%). 展开更多
关键词 mechanochemical method Ni-Al2O3 catalyst 1 4-butynediol ball-milling time
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Fe基分子筛催化剂应用于NH3选择性催化还原和N2O直接催化分解反应的研究进展 认领 引用 被引量：1
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作者 明淑君 李新楠 +4 位作者 庞磊 苏长罗 程春晖 杨小东 李涛 《低碳化学与化工》 CAS 北大核心 2025年第6期97-112,共16页
柴油车排放的氮氧化物(NOx)和氧化亚氮(N2O)对人类健康和生态环境造成了显著危害。NH3选择性催化还原(NH3-SCR)技术是当前控制柴油车尾气中NOx排放的有效方法之一,而N2O的直接催化分解(简称“N2O分解”)则被认为... 柴油车排放的氮氧化物(NOx)和氧化亚氮(N2O)对人类健康和生态环境造成了显著危害。NH3选择性催化还原(NH3-SCR)技术是当前控制柴油车尾气中NOx排放的有效方法之一,而N2O的直接催化分解(简称“N2O分解”)则被认为是减少N2O排放的最具潜力的技术。这两种技术的核心均依赖于催化剂的开发与应用。Fe基分子筛催化剂在NH3-SCR和N2O分解反应中展现出了卓越的催化性能,为实现NOx和N2O的同步高效去除提供了一条有前途的路径。综述了Fe基分子筛催化剂在NH3-SCR和N2O分解反应中的催化机理,探讨了Fe基分子筛催化剂的制备方法、拓扑结构、助剂金属掺杂,以及反应环境中共存气体对其理化性质、NH3-SCR活性和N2O分解性能的影响。具体而言,Fe基分子筛催化剂的Fe物种形成与分布受到制备方法和分子筛拓扑结构的显著影响。助剂金属的引入不仅能够增大催化剂的酸性位点含量,还能改善Fe物种的分散性,从而优化其催化性能。此外,共存气体(如NO、O2和H2O)对Fe基分子筛催化剂的N2O分解活性产生不同程度的影响。最后,对Fe基分子筛催化剂的未来研究方向进行了展望,并对催化剂设计优化与性能提升提出了建议。 展开更多
关键词 Fe基分子筛催化剂 NH3-SCR N2O直接催化分解 催化机理
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控制高碳钢中CaO-Al_2O_3-SiO_2类夹杂物成分的实验研究 认领 引用 被引量：32
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作者 王立峰 王新华 +2 位作者 张炯明 王万军 卓小军 《钢铁》 EI CAS 北大核心 2004年第1期21-23,共3页
采用高温管式炉研究了低碱度顶渣对高碳钢中夹杂物成分的影响。热力学计算和实验结果表明 ,当炉渣碱度在 0 .71～ 1.36 ,Al2 O3含量在 8%以下时 ,钢中的酸溶铝含量在 0 .0 0 0 6 %以下 ,钢中 Ca O- Al2 O3-Si O2 类夹杂物的 Ca O/ Si O2... 采用高温管式炉研究了低碱度顶渣对高碳钢中夹杂物成分的影响。热力学计算和实验结果表明 ,当炉渣碱度在 0 .71～ 1.36 ,Al2 O3含量在 8%以下时 ,钢中的酸溶铝含量在 0 .0 0 0 6 %以下 ,钢中 Ca O- Al2 O3-Si O2 类夹杂物的 Ca O/ Si O2 在 1.5以下 ,Al2 O3含量为 8%～ 2 5 % ,夹杂物的成分在塑性区内。 展开更多
关键词 高碳钢 CaO-Al2O3-SiO2 脱氧 夹杂物 成分控制
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遮光剂掺杂Al_2O_3-SiO_2气凝胶/莫来石纤维毡复合材料的高温隔热性能研究 认领 引用 被引量：27
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作者 朱召贤 王飞 +2 位作者 姚鸿俊 董金鑫 龙东辉 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2018年第9期969-975,共7页
分别以TiCl_4和ZrOCl_2·8H_2O作为钛源和锆源,经过溶胶–凝胶和超临界CO_2干燥过程,将遮光剂粒子TiO_2和ZrO_2掺入到Al_2O_3-SiO_2气凝胶,并进一步以莫来石纤维毡为增强相制备出具有一定力学性能的耐高温气凝胶复合材料,分别探究... 分别以TiCl_4和ZrOCl_2·8H_2O作为钛源和锆源,经过溶胶–凝胶和超临界CO_2干燥过程,将遮光剂粒子TiO_2和ZrO_2掺入到Al_2O_3-SiO_2气凝胶,并进一步以莫来石纤维毡为增强相制备出具有一定力学性能的耐高温气凝胶复合材料,分别探究了两种遮光剂粒子对复合材料的微观结构、力学性能和热导率的影响。结果显示:遮光剂粒子的引入可以有效阻止气凝胶在高温下的塌陷和团聚,保持气凝胶高孔隙率的特性;复合材料呈现典型的气凝胶填充纤维结构,并且具有轻质(0.21~0.24 g·cm–1)和高强度(弯曲强度为0.98~1.26 MPa)的优异性能,拓展了材料的实用性;在1050℃的高温下,由于TiO_2和ZrO_2粒子对红外电磁波具有吸收和散射作用,可以将复合材料的热导率由0.098 W·m-1·K-1分别降低至0.085 W·m-1·K-1和0.076 W·m-1·K-1,从而有效提高材料的高温隔热性能。 展开更多
关键词 Al2O3-SiO2气凝胶 红外遮光剂 热导率 高温隔热性能
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Effect of Fe_2O_3 on non-isothermal crystallization of CaO-MgO-Al_2O_3-SiO_2 glass 认领 引用 被引量：10
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作者 郁青春 燕春培 +3 位作者 邓勇 冯月斌 刘大春 杨斌 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第7期2279-2284,共6页
The crystallization behavior and kinetics of CaO-MgO-Al2O3 SiO2（CMAS） glass with the Fe2O3 content ranging from zero to 5%were investigated by differential scanning calorimetry（DSC）.The structure and phase analyse... The crystallization behavior and kinetics of CaO-MgO-Al2O3 SiO2（CMAS） glass with the Fe2O3 content ranging from zero to 5%were investigated by differential scanning calorimetry（DSC）.The structure and phase analyses were made by Fourier transform infrared spectroscopy（FT-IR） and X-ray diffraction（XRD）.The experiment results show that the endothermic peak temperature about 760℃ is associated with transition and the exothermic peak temperature about 1000℃ is associated with crystallization.The crystallization peak temperature decreases with increasing the Fe203 content.The crystallization mechanism is changed from two-dimensional crystallization to one-dimensional growth,and the intensity of diopside peaks becomes stronger gradually.There is a saltation for the crystallization temperature with the addition of 0.5%Fe2O3 due to the decomposition of Fe2O3.Si-O-Si,O-Si-O and T-O-T（T=Si,Fe,Al） linkages are observed in Fe2O3-CaO-MgO-Al2O3-SiO2 glass. 展开更多
关键词 CaO-MgO-Al2O3-SiO2 glass Fe2O3 diopside crystallization kinetics
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Highly selective catalytic reduction of NO_x by MnO_x–CeO_2–Al_2O_3 catalysts prepared by self-propagating high-temperature synthesis 认领 引用 被引量：14
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作者 Chao Wang Feng Yu +5 位作者 Mingyuan Zhu Changjin Tang Ke Zhang Dan Zhao Lin Dong Bin Dai 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2019年第1期124-135,共12页
We first present preparation of MnOx–CeO_2–Al_2O_3 catalysts with varying Mn contents through a self-propagating high-temperature synthesis(SHS) method, and studied the application of these catalysts to the selectiv... We first present preparation of MnOx–CeO_2–Al_2O_3 catalysts with varying Mn contents through a self-propagating high-temperature synthesis(SHS) method, and studied the application of these catalysts to the selective catalytic reduction of NOxwith NH3(NH_3-SCR).Using the catalyst with 18 wt.% Mn(18 MnCe1Al2), 100% NO conversion was achieved at 200°C and a gas hourly space velocity of 15384 hr-1, and the high-efficiency SCR temperature window, where NO conversion is greater than 90%, was widened to a temperature range of 150–300°C. 18 MnCe1Al2 showed great resistance to SO_2(100 ppm)and H_2O(5%) at 200°C. The catalysts were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller(BET) analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, and H_2 temperature programmed reduction. The characterization results showed that the surface atomic concentration of Mn increased with increasing Mn content, which led to synergism between Mn and Ce and improved the activity in the SCR reaction. 18 MnCe1Al2 has an extensive pore structure,with a BET surface area of approximately 135.4 m^2/g, a pore volume of approximately 0.16 cm^3/g, and an average pore diameter of approximately 4.6 nm. The SCR reaction on 18 MnCe1Al2 mainly followed the Eley-Rideal mechanism. The performances of the MnOx–CeO_2–Al_2O_3 catalysts were good, and because of the simplicity of the preparation process,the SHS method is applicable to their industrial-scale manufacture. 展开更多
关键词 NH3-SCR SHS method MnOx-CeO2-Al2O3 catalyst NOx removal efficiency
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Improving the denitration performance and K-poisoning resistance of the V_2O_5-WO_3/TiO_2 catalyst by Ce4+ and Zr4+ co-doping 认领 引用 被引量：21
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作者 Jun Cao Xiaojiang Yao +4 位作者 Fumo Yang Li Chen Min Fu Changjin Tang Lin Dong 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第1期95-104,共10页
A series of V2O5‐WO3/TiO2‐ZrO2,V2O5‐WO3/TiO2‐CeO2,and V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalysts were synthesized to improve the selective catalytic reduction(SCR)performance and the K‐poisoning resistance of a V2O5‐W... A series of V2O5‐WO3/TiO2‐ZrO2,V2O5‐WO3/TiO2‐CeO2,and V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalysts were synthesized to improve the selective catalytic reduction(SCR)performance and the K‐poisoning resistance of a V2O5‐WO3/TiO2 catalyst.The physicochemical properties were investigated by using XRD,BET,NH3‐TPD,H2‐TPR,and XPS,and the catalytic performance and K‐poisoning resistance were evaluated via a NH3‐SCR model reaction.Ce^4+and Zr^4+co‐doping were found to enhance the conversion of NOx,and exhibit the best K‐poisoning resistance owing to the largest BET‐specific surface area,pore volume,and total acid site concentration,as well as the minimal effects on the surface acidity and redox ability from K poisoning.The V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalyst also presents outstanding H2O+SO2 tolerance.Finally,the in situ DRIFTS reveals that the NH3‐SCR reaction over the V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalyst follows an L‐H mechanism,and that K poisoning does not change the reaction mechanism. 展开更多
关键词 V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalyst Co‐doping K‐poisoning NH3‐SCR Reaction mechanism
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Bi_2O_3助熔剂对CaO-B_2O_3-SiO_2/Al_2O_3玻璃-陶瓷复合材料性能的影响 认领 引用 被引量：10
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作者 方一航 王焕平 +3 位作者 李志刚 黄小华 赵先锐 李勤涛 《复合材料学报》 EI CAS CSCD 北大核心 2014年第6期1509-1515,共7页
以CaO-B2O3-SiO2(CBS)玻璃粉体和Al2O3陶瓷粉体为原料,通过在CBS与Al2O3的质量比固定为50∶50的玻璃-陶瓷复合材料中添加适量的Bi2O3作为烧结助熔剂,探讨了Bi2O3助熔剂对CBS/Al2O3复合材料的烧结性能、介电性能、抗弯强度和热膨胀系数... 以CaO-B2O3-SiO2(CBS)玻璃粉体和Al2O3陶瓷粉体为原料,通过在CBS与Al2O3的质量比固定为50∶50的玻璃-陶瓷复合材料中添加适量的Bi2O3作为烧结助熔剂,探讨了Bi2O3助熔剂对CBS/Al2O3复合材料的烧结性能、介电性能、抗弯强度和热膨胀系数的影响规律。研究表明:Bi2O3助熔剂能通过降低CBS玻璃的转变温度和黏度促进CBS/Al2O3复合材料的致密化进程,于880℃下烧结即能获得结构较致密、气孔较少的CBS/Al2O3复合材料。然而,过量添加Bi2O3将使玻璃的黏度过低,从而恶化CBS/Al2O3复合材料的烧结性能、介电性能及抗弯强度。当Bi2O3的添加量为CBS/Al2O3复合材料的1.5wt%时,于880℃下烧结即能获得最为致密的CBS/Al2O3复合材料,密度为2.82g·cm-3,这一材料具有良好的介电性能(介电常数为7.21,介电损耗为1.06×10-3),抗弯强度为190.34 MPa,0~300℃的热膨胀系数为3.52×10-6 K-1。 展开更多
关键词 CaO-B2O3-SiO2/Al2O3 Bi2O3 烧结性能 介电性能 抗弯强度 热膨胀系数
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La_2O_3在MgO-Al_2O_3-SiO_2-TiO_2微晶玻璃中的作用 认领 引用 被引量：17
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作者 迟玉山 沈菊云 +1 位作者 陈学贤 缪之训 《无机材料学报》 SCIE EI CAS 北大核心 2002年第2期348-352,共5页
在MgO－Al2O3－SiO2－TiO2玻璃中添加不同数量的氧化镧，采用差热分析、X射线衍射及电子显微镜等技术研究了氧化镧对玻璃析晶过程与力学性能的影响．氧化镧的加入使玻璃中析出α－堇青石相的温度降低；同时避免了高膨胀方石英相的析出... 在MgO－Al2O3－SiO2－TiO2玻璃中添加不同数量的氧化镧，采用差热分析、X射线衍射及电子显微镜等技术研究了氧化镧对玻璃析晶过程与力学性能的影响．氧化镧的加入使玻璃中析出α－堇青石相的温度降低；同时避免了高膨胀方石英相的析出．随着氧化镧加入量的增加，玻璃整体析晶能力下降，微晶玻璃中晶相含量减少，晶粒尺寸增大，微晶玻璃的弹性模量与硬度减小，断裂韧性增加，体现出大尺寸长柱状金红石晶粒的增韧作用． 展开更多
关键词 MgO-Al2O3-SiO2-TiO2 微晶玻璃 La2O3 晶化 断裂韧性
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Performance of V_2O_5-WO_3-MoO_3/TiO_2 Catalyst for Selective Catalytic Reduction of NO_x by NH_3 认领 引用 被引量：17
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作者 高岩 栾涛 +2 位作者 吕涛 程凯 徐宏明 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第1期1-7,共7页
The V/O5-WO3-MoOy＇TiO2 honeycomb catalyst was prepared with industrial grade chemicals. The structural and physico-chemical properties were analyzed with X-ray diffraction （XRD）, scanning electron micrograph （SEM... The V/O5-WO3-MoOy＇TiO2 honeycomb catalyst was prepared with industrial grade chemicals. The structural and physico-chemical properties were analyzed with X-ray diffraction （XRD）, scanning electron micrograph （SEM） and mercury porosimetry. The NOx conversion and durability were investigated on a pilot plant test set under the actual operational conditions of a coal fired boiler. The catalyst monolith had good formability with mass per- centage of V ： W ： Mo ： TiO2 ： fiber glass = 1 ： 4.5 ： 4.5 ： 72 ： 18. Vanadium, tungsten and molybdenum species were highly dispersed on anatase TiO2 without causing the transformation of anatase TiO2 to ruffle by calcining under a current of air at 450℃ for 4.5 h, but there were some degrees of crystal distortion. The catalyst particle sizes were almost uniform with close pile-up and the pore structure was regular with complete macro-pore formation and large specific surface area. The NOx conversion was sensitive to temperature but nearly insensitive to NH3. The catalyst showed strong adaptability to NOx concentration with activity above 80% in the range of 615 1640 mg.m-3. Within the range of 720-8640 h continuous operation, the NOx conversion dropped at a rate of about 1% reduction per 600 h. 展开更多
关键词 selective catalytic reduction V2O5-WO3-MoO3/ZiO2 catalyst physico-chemical property flue gas life time
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Microstructure and microwave dielectric properties of CaO-B_2O_3-SiO_2 glass ceramics with various B_2O_3 contents 认领 引用 被引量：11
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作者 韦鹏飞 周洪庆 +2 位作者 朱海奎 戴斌 王杰 《Journal of Central South University》 SCIE EI CAS 2011年第5期1359-1364,共6页
The effects of B2O3 addition on both the sintering behavior and microwave dielectric properties of CaO-B2O3-SiO2 （CBS） glass ceramics were investigated by Fourier transform infrared spectroscopy （FTIR）, X-ray diff... The effects of B2O3 addition on both the sintering behavior and microwave dielectric properties of CaO-B2O3-SiO2 （CBS） glass ceramics were investigated by Fourier transform infrared spectroscopy （FTIR）, X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. The results show that the increasing amount of B203 causes the increase of the contents of [BO3], [BO4] and [SiO4], which deduces the increase of CaB204 and a-SiO2 and the decrease of CaSiO3 correspondingly. No new phase is observed throughout the entire experiments. A bulk density of 2.54 g/cm3, a thermal expansion coefficient value of 11.95× 10-6 ℃-1 （20-500℃）, a dielectric constant er value of 6.42 and a dielectric loss tanδ value of 0.000 9 （measured at 9.7 GHz） are obtained for CBS glass ceramics containing 35%-B203 （mass fraction） sintered at 850 ℃ for 15 min. 展开更多
关键词 CaO-B2O3-SiO2 B2O3 content Fourier transform infrared spectroscopy microstructure dielectric properties
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Effect of Ce doping into V2O5-WO3/TiO2 catalysts on the selective catalytic reduction of NOx by NH3 认领 引用 被引量：27
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作者 Mengyin Chen Mengmeng Zhao +3 位作者 Fushun Tang Le Ruan Hongbin Yang Ning Li 《Journal of Rare Earths》 SCIE EI CAS CSCD 2017年第12期1206-1215,共10页
In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied compara... In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied comparatively by various experimental techniques. The results showed that the NO conversion of V2O5-WO3/CeO2-TiO2 catalysts modified by co-precipitation method obviously increased with the Ce doping contents in the studied range below 20%（All Ce contents are in mass fractions）, but the NO conversion of V2O5-WO3/CeO2/TiO2 catalysts modified by impregnation methods was lower than V2O5-WO3/CeO2-TiO2 catalysts especially beyond 2.5% Ce doping contents. The V2O5-WO3/CeO2-TiO2 catalysts showed better SCR activity, wider reaction window, and higher sulfur and water resistance. The characterization results elucidated that the modified catalysts by co-precipitation method exhibited higher specific surface area, much better dispersity of Ce component, more Ce^（3＋）species and more Br？nsted acid sites than that by impregnation. The vacancies caused by more Ce^（3＋）species were favorable for more NO oxidation to NO2, and the interaction between Ce species and WOxspecies generated more Br？nsted acid sites. It could be supposed that dispersed Ce Oxspecies and WOxspecies offered more second active centers respectively to adsorb oxygen and activate ammonia as co-catalysis to the primary active center of V ions, thus facilitated the better SCR activity of modified V2O5-WO3/CeO2-TiO2 catalysts by coprecipitation methods. The co-precipitation methods with Ce component were more suitable for production of modified commercial V2O5-WO3/TiO2 catalysts. 展开更多
关键词 V2O5-WO3/TiO2 catalysts Ce doping methods NH3 selective catalytic reduction NOx Dispersion state Reducibility Br?nsted acid sites
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MgO-Al_2O_3-SiO_2系玻璃受控晶化研究 认领 引用 被引量：30
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作者 邢军 宋守志 +1 位作者 刘渭萍 王玉新 《东北大学学报（自然科学版）》 EI CAS 北大核心 2000年第5期558-561,共4页
根据微晶玻璃的基础组成 ,以菱镁矿渣和大同砂为主要原料 ,从晶格匹配、最低共熔点、成型等方面确定MgO Al2 O3 SiO2 系玻璃主成分和选择晶核剂·用差热分析、X射线衍射、扫描电镜和偏光显微镜观测等手段 ,优选晶核剂 ,研究了以TiO2... 根据微晶玻璃的基础组成 ,以菱镁矿渣和大同砂为主要原料 ,从晶格匹配、最低共熔点、成型等方面确定MgO Al2 O3 SiO2 系玻璃主成分和选择晶核剂·用差热分析、X射线衍射、扫描电镜和偏光显微镜观测等手段 ,优选晶核剂 ,研究了以TiO2 和Cr2 O3为晶核剂的微晶玻璃的晶化速率、晶相组成和微观结构 ,晶化结果表明 :添加合适晶核剂将形成中间相 ,通过中间相诱导析晶 ,主晶相为堇青石 ;复合晶核剂可提高晶化速率 。 展开更多
关键词 晶核剂 晶化 晶相 微晶玻璃 受控晶化 MGO-AL2O3-SIO2系玻璃
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P2O5对CaO-MgO-Al2O3-SiO2系微晶玻璃析晶的影响 认领 引用 被引量：14
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作者 田清波 徐丽娜 +2 位作者 岳雪涛 王修慧 高宏 《人工晶体学报》 EI CAS 北大核心 2008年第1期208-212,共5页
采用熔融法制备了不同P2O5含量的CaO-MgO-Al2O3-SiO2玻璃样品,研究了P2O5对该系微晶玻璃析晶的影响规律。结果表明:在所研究的CaO-MgO-Al2O3-SiO2玻璃中,P2O5的最大溶解量在10.0%质量分数左右,超过其饱和溶解度后将析出α-磷酸钙相。玻... 采用熔融法制备了不同P2O5含量的CaO-MgO-Al2O3-SiO2玻璃样品,研究了P2O5对该系微晶玻璃析晶的影响规律。结果表明:在所研究的CaO-MgO-Al2O3-SiO2玻璃中,P2O5的最大溶解量在10.0%质量分数左右,超过其饱和溶解度后将析出α-磷酸钙相。玻璃中添加4.0%质量分数P2O5时以表面析晶为主,析出晶体为钙长石和少量硅灰石。随着P2O5含量的提高,α-磷酸钙逐渐析出,同时钙长石和硅灰石的析出逐渐降低。进一步提高P2O5含量抑制了玻璃的表面析晶,促进了玻璃的分相和整体析晶。当P2O5的含量达到10%时,玻璃以整体析晶为主,在分相区内外区域析出晶体的形态非常相似,均呈现为细小粒状。 展开更多
关键词 微晶玻璃 五氧化二磷 析晶 CaO-MgO-Al2O3-SiO2玻璃
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