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Activity and hydrothermal stability of CeO_2–ZrO_2–WO_3 for the selective catalytic reduction of NO_x with NH_3 认领 引用 被引量：7
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作者 Zhongxian Song Ping Ning +5 位作者 Qiulin Zhang Hao Li Jinhui Zhang Yancai Wang Xin Liu Zhenzhen Huang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第4期168-177,共10页
A series of CeO2–ZrO2–WO3（CZW）catalysts prepared by a hydrothermal synthesis method showed excellent catalytic activity for selective catalytic reduction（SCR）of NO with NH3 over a wide temperature of 150–550℃.... A series of CeO2–ZrO2–WO3（CZW）catalysts prepared by a hydrothermal synthesis method showed excellent catalytic activity for selective catalytic reduction（SCR）of NO with NH3 over a wide temperature of 150–550℃.The effect of hydrothermal treatment of CZW catalysts on SCR activity was investigated in the presence of 10% H2O.The fresh catalyst showed above 90% NOx conversion at 201–459℃,which is applicable to diesel exhaust NOx purification（200–440℃）.The SCR activity results indicated that hydrothermal aging decreased the SCR activity of CZW at low temperatures（below 300℃）,while the activity was notably enhanced at high temperature（above 450℃）.The aged CZW catalyst（hydrothermal aging at 700℃ for 8 hr）showed almost 80% NOx conversion at 229–550℃,while the V2O5–WO3/TiO2 catalyst presented above 80% NOx conversion at 308–370℃.The effect of structural changes,acidity,and redox properties of CZW on the SCR activity was investigated.The results indicated that the excellent hydrothermal stability of CZW was mainly due to the CeO2–ZrO2 solid solution,amorphous WO3 phase and optimal acidity.In addition,the formation of WO3 clusters increased in size as the hydrothermal aging temperature increased,resulting in the collapse of structure,which could further affect the acidity and redox properties. 展开更多
关键词 CeO2–ZrO2–WO3 Hydrothermal stability Solid solution Acidity
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Influence of calcination temperature on selective catalytic reduction of NO_x with NH_3 over CeO_2-ZrO_2-WO_3 catalyst 认领 引用 被引量：16
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作者 李军燕 宋忠贤 +4 位作者 宁平 张秋林 刘昕 李昊 黄真真 《Journal of Rare Earths》 SCIE EI CAS CSCD 2015年第7期726-735,共10页
A series of CeO2-ZrO2-WO3 catalysts for the selective catalytic reduction （SCR） of NO with NH3 were prepared by hydrothermal method. The influence of calcination temperature on the catalytic activity, microstructure... A series of CeO2-ZrO2-WO3 catalysts for the selective catalytic reduction （SCR） of NO with NH3 were prepared by hydrothermal method. The influence of calcination temperature on the catalytic activity, microstructure, surface acidity and redox behavior of CeO2-ZrO2-WO3 catalyst was investigated using various characterization methods. It was found that the CeO2-ZrO2-WO3 catalyst calcined at 600 ℃ showed the best catalytic performance and excellent N2 selectivity, and yielded more than 90% NO conversion in a wide temperature range of 250-500 ℃ with a space velocity （GHSV） of 60000 131. As the calcination temperature was increased from 400 to 600 ℃, the NO conversion obviously increased, but decreased at higher calcination temperature. The results implied that the higher surface area, the strongest synergistic interaction, the superior redox property and the highly dispersed or amorphous WO3 species contributed to the excellent SCR activity of the CeO2-ZrO2-WO3 catalyst calcined at 600℃. 展开更多
关键词 CeO2-ZrO2-WO3 selective catalytic reduction calcination temperature amorphous synergistic interaction rare earths
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CeO_2/ZrO_2物质的量比对CeO_2-ZrO_2-WO_3催化剂在NH_3选择性催化还原NO中的影响:氧化还原性能和表面酸性的探讨 认领 引用 被引量：2
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作者 宋忠贤 张秋林 +3 位作者 宁平 张金辉 王燕彩 唐小苏 《化学世界》 CAS CSCD 2016年第1期20-24,29,共5页
采用水热法制备了一系列的催化剂用于NH3选择催化还原NO，通过不同的CeO2／ZrO2物质的量比考察催化剂的氧化还原性能和表面酸性对其催化活性的影响。采用XRD、H2-TPR、NH3TPD等表征手段对催化剂进行了表征，结果表明：当CeO2／ZrO2物质... 采用水热法制备了一系列的催化剂用于NH3选择催化还原NO，通过不同的CeO2／ZrO2物质的量比考察催化剂的氧化还原性能和表面酸性对其催化活性的影响。采用XRD、H2-TPR、NH3TPD等表征手段对催化剂进行了表征，结果表明：当CeO2／ZrO2物质的量比为5：5时，催化剂拥有最强的氧化还原能力和较多的弱酸和中强酸，从而在200～430℃区间内该催化剂拥有90％以上的NOx去除率。此外，10％（体积分数）H2O对该催化剂低温活性有抑制作用，在213～500℃区间内，H2O对SCR活性没有影响，在225～500℃区间内，NOx的去除率达到100％。 展开更多
关键词 选择性催化还原 CeO2/ZrO2 氧化还原性能 酸度
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Positive effects of SO2 on NH3-SCR at high temperatures and their relationship with the structure of tungsten on Ce-W oxides 认领 引用
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作者 Hexiang Wang Ligang Zhang +2 位作者 Fan Wang Wen Liu Kuo Liu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第6期233-241,共9页
CeW-based catalysts with W species in different states,i.e.,a CeW oxide with only crystalline WO3(CeW-C)and a CeW oxide with monomeric W species(CeW-M),were prepared by a simple coprecipitation method through chang... CeW-based catalysts with W species in different states,i.e.,a CeW oxide with only crystalline WO3(CeW-C)and a CeW oxide with monomeric W species(CeW-M),were prepared by a simple coprecipitation method through changing the mixing time during preparation.SO2was found to exert a positive effect on NH3-SCR at high temperatures,and CeW-C exhibited higher resistance toward SO2poisoning.CeW-M with monomericWexhibited higher activity above 200°C in the absence of SO2than CeW-C with crystalline WO3due to the higher dispersion of W and the resulting increased number of acid sites for NH3adsorption.CeW-C with crystalline WO3possessed a higher amount of reducible oxygen species,leading to greater NO and SO2adsorption,as well as causing higher activity below 200℃in the absence of SO2.In the presence of SO2,NH3adsorption was promoted by forming(NH 4)2 SO 4 or NH4HSO4,which could react with NO to form N2and H2O on CeW-C.Having a large amount of NH3adsorption was important for high NH3-SCR activity on these Ce-W oxides,and SO2exerted a positive effect on NH3-SCR by promoting NH3adsorption at high temperatures.Additionally,more nitrates remained on CeW-C with crystalline WO3in the presence of SO2.The reasons above led to better SO2resistance for CeW-C.The different states of W species affect the NH3-SCR activity and ability to resist SO2and H2O poisoning by changing the redox properties,number of acid sites,and adsorption of NO,NH3and SO2. 展开更多
关键词 NH3-SCR Promotional effects of SO2 Monomeric W species Crystalline WO3
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焙烧温度对MnO_x-CeO_2-WO_3-ZrO_2催化剂上NH_3选择性还原NO的影响(英文) 认领 引用 被引量：2
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作者 于在璐 谢鹏飞 +3 位作者 唐幸福 乐英红 华伟明 高滋 《物理化学学报》 SCIE CAS CSCD 北大核心 2014年第6期1175-1179,共5页
采用共沉淀法制备了MnOx-CeO2-WO3-ZrO2催化剂,考察了催化剂焙烧温度对O2和H2O存在下NH3选择性催化还原(NH3-SCR)NO的影响,并利用低温N2吸附、X射线衍射(XRD)、透射电镜(TEM)、X射线光电子能谱(XPS)、NH3程序升温脱附(NH3-TPD)和CO脉冲... 采用共沉淀法制备了MnOx-CeO2-WO3-ZrO2催化剂,考察了催化剂焙烧温度对O2和H2O存在下NH3选择性催化还原(NH3-SCR)NO的影响,并利用低温N2吸附、X射线衍射(XRD)、透射电镜(TEM)、X射线光电子能谱(XPS)、NH3程序升温脱附(NH3-TPD)和CO脉冲反应对催化剂进行了表征.结果表明在NH3-SCR反应中,催化剂的低温活性随焙烧温度的提高而降低,这是由于催化剂表面化学吸附氧和酸性位减少引起的;催化剂的高温活性随焙烧温度的提高先增加后减小,这与催化剂表面最易释放氧数量的变化趋势相反.700°C焙烧的催化剂具有良好的低温活性和最宽的反应温度窗口,在空速为90000 h-1的条件下,该催化剂的起燃温度(50%NO转化率)为189°C,且反应温度在218-431°C范围内,NO转化率可达到80%-100%. 展开更多
关键词 氮氧化物 选择性催化还原 氧化锰 氧化铈 氧化钨-氧化锆 共沉淀法 WO3-ZrO2
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ZrO2-TiO2-CeO2的制备及其在NH_3选择性催化还原NO中的应用 认领 引用 被引量：18
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作者 林涛 李伟 +3 位作者 龚茂初 喻瑶 杜波 陈耀强 《物理化学学报》 SCIE CAS 北大核心 2007年第12期1851-1856,共6页
采用共沉淀法制备了载体材料TiO2、ZrO2-TiO2及ZrO2-TiO2-CeO2,并利用X射线衍射(XRD)实验、比表面积测定(BET)、程序升温脱附(NH3-TPD)、储氧性能测定(OSC)及程序升温还原(H2-TPR)等方法对三种载体材料进行了表征.结果表明,ZrO2-TiO2-C... 采用共沉淀法制备了载体材料TiO2、ZrO2-TiO2及ZrO2-TiO2-CeO2,并利用X射线衍射(XRD)实验、比表面积测定(BET)、程序升温脱附(NH3-TPD)、储氧性能测定(OSC)及程序升温还原(H2-TPR)等方法对三种载体材料进行了表征.结果表明,ZrO2-TiO2-CeO2具有较多的表面强酸位,并具有一定的储氧性能和较强的氧化还原性能.以三种材料为载体,制备了质量分数分别为1%、9%的V2O5、WO3的整体式催化剂.研究了三种催化剂在富氧条件下用NH3选择性催化还原NO的催化性能.结果表明,以ZrO2-TiO2-CeO2为载体的催化剂在反应空速为10000h-1,275℃时,NO的转化率接近100%,具有最好的催化活性,并有良好的应用前景. 展开更多
关键词 ZrO2-TiO2-CeO2 ZrO2-TiO2 TiO2 选择性催化还原 NO NH3
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Catalytic performance of highly dispersed WO_3 loaded on CeO_2 in the selective catalytic reduction of NO by NH_3 认领 引用 被引量：9
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作者 Lei Zhang Jingfang Sun +3 位作者 Yan Xiong Xiaoqing Zeng Changjin Tang Lin Dong 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第10期1749-1758,共10页
The influence of tungsten trioxide(WO3)loading on the selective catalytic reduction(SCR)of nitric oxide(NO)by ammonia(NH3)over WO3/cerium dioxide(CeO2)was investigated.The NO conversion first rose and then declined wi... The influence of tungsten trioxide(WO3)loading on the selective catalytic reduction(SCR)of nitric oxide(NO)by ammonia(NH3)over WO3/cerium dioxide(CeO2)was investigated.The NO conversion first rose and then declined with increasing WO3loading.It was found that the crystalline WO3in the1.6WO3/CeO2sample could be removed in25wt%ammonium hydroxide at70°C,which improved the catalytic activity of the sample.The obtained samples were characterized by X‐ray diffraction,Raman spectroscopy,X‐ray photoelectron spectroscopy,hydrogen(H2)temperature programmed reduction,NH3temperature programmed desorption,and in situ diffuse reflectance infrared Fourier transform spectroscopy.The results revealed that the dispersed WO3promoted the catalytic activity of WO3/CeO2while the crystalline WO3inhibited catalytic activity.The oxygen activation of CeO2was inhibited by the coverage of WO3,which weakened NO oxidation and adsorption of nitrate species over WO3/CeO2.In addition,the NH3adsorption performance on CeO2was improved by modification with WO3.NH3was the most stable adsorbed species under NH3SCR reaction conditions.In situ DRIFT spectra suggested that the NH3SCR reaction proceeded via the Eley‐Rideal mechanism over WO3/CeO2.Thus,when the loading of WO3was close to the dispersion capacity,the effects of NH3adsorption and activation were maximized to promote the reaction via the Eley‐Rideal route. 展开更多
关键词 NH3 selective catalytic reduction WO3/CeO2 catalyst WO3 state Dispersion capacity Diffuse reflectance infrared Fourier transform spectroscopy
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Effect of praseodymium additive on CeO2(ZrO2)/TiO2 for selective catalytic reduction of NO by NH3 认领 引用 被引量：14
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作者 金奇杰 沈岳松 +3 位作者 祝社民 刘青 李喜红 严巍 《Journal of Rare Earths》 SCIE EI CAS CSCD 2016年第11期1111-1120,共10页
A series of praseodymium added CeO2（ZrO2）/TiO2 catalysts separately prepared by methods of sol-gel and impregnation were tested for selective catalytic reduction of NO, and characterized by X-ray diffraction （XRD）... A series of praseodymium added CeO2（ZrO2）/TiO2 catalysts separately prepared by methods of sol-gel and impregnation were tested for selective catalytic reduction of NO, and characterized by X-ray diffraction （XRD）, N2-brumauer-emmett-teller （N2-BET）, NH3-temperature programmed desorption （NH3-TPD）, H2-temperature programmed reduction （H2-TPR）, PL spectra, Ra-man spectra, electron paramagnetic resonance （EPR） and X-ray photoelectron spectroscopy （XPS）, respectively. Influence of prepara-tion method on catalytic performance was studied. Results showed that the influence of Pr addition on catalytic performance of the CeO2（ZrO2）/TiO2 catalysts was different between the sol-gel method and the impregnation method. The Pr addition tended to interact with TiO2 and formed the structure of Ti-O-Pr in the sol-gel method while it was more likely to interact with CeO2 forming the struc-ture of Ce-O-Pr in the impregnation method. The total acid amount and redox properties of the catalysts prepared by sol-gel method decreased with the addition of Pr element, which resulted in decrease of catalytic activity. In contrast, the Pr-added catalyst prepared by impregnation method was found to possess easier reducibility, more total acid amount and higher proportion of Ce3＋ species, which was favourable for higher catalytic activity. 展开更多
关键词 praseodymium-added CeO2（ZrO2）/TiO2 preparation method selective catalytic reduction catalytic performance rare earths
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Promotional effects of Er incorporation in CeO_2(ZrO_2)/TiO_2 for selective catalytic reduction of NO by NH_3 认领 引用 被引量：12
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作者 Qijie Jin Yuesong Shen +2 位作者 Shemin Zhu Xihong Li Min Hu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第9期1521-1529,共9页
A series CeO2（ZrO2）/TiO2 catalysts were modified with Er using a sol-gel method.The catalytic activity of the obtained catalysts in the selective catalytic reduction（SCR） of NO with NH3 was investigated to determi... A series CeO2（ZrO2）/TiO2 catalysts were modified with Er using a sol-gel method.The catalytic activity of the obtained catalysts in the selective catalytic reduction（SCR） of NO with NH3 was investigated to determine the appropriate Er dosage.The catalysts were characterized using X-ray diffraction,N2 adsorption,NH3 temperature-programmed desorption,H2 temperature-programmed reduction,photoluminescence spectroscopy,electron paramagnetic resonance spectroscopy,and X-ray photoelectron spectroscopy.The results showed that the optimum Er/Ce molar ratio was 0.10;this catalyst had excellent resistance to catalyst poisoning caused by vapor and sulfur and gave more than 90% NO conversion at 220–395 ℃ and a gas hourly space velocity of 71 400 h^-1.Er incorporation increased the Ti^3＋ concentrations,oxygen storage capacities,and oxygen vacancy concentrations of the catalysts,resulting in excellent catalytic performance.Er incorporation also decreased the acid strength and inhibited growth of TiO2 and CeO2 crystal particles,which increased the catalytic activity.The results show that high oxygen vacancy concentrations and oxygen storage capacities,large amounts of Ti^3＋,and low acid strengths give excellent SCR activity. 展开更多
关键词 CeO2（ZrO2）/TiO2 Erbium incorporation Selective catalytic reduction Nitrogen oxide Catalytic performance
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改性WO_3/ZrO_2固体超强酸催化合成乙酰水杨酸 认领 引用 被引量：10
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作者 张存 吴过 +3 位作者 潘小玉 郁美净 金亮 刘晓勤 《四川大学学报（工程科学版）》 CSCD 北大核心 2013年第2期136-141,共6页
采用共沉淀法制备WO3/ZrO2及Ce、Mn改性WO3/ZrO2固体超强酸,通过XRD、Raman等方法对改性前后催化剂进行表征,并将其分别用于乙酰水杨酸合成反应考察催化性能,结果表明Ce改性WO3/ZrO2固体超强酸催化效果最好。以Ce改性WO3/ZrO2固体超强... 采用共沉淀法制备WO3/ZrO2及Ce、Mn改性WO3/ZrO2固体超强酸,通过XRD、Raman等方法对改性前后催化剂进行表征,并将其分别用于乙酰水杨酸合成反应考察催化性能,结果表明Ce改性WO3/ZrO2固体超强酸催化效果最好。以Ce改性WO3/ZrO2固体超强酸作为催化剂对乙酰水杨酸合成工艺进行优化,考察反应时间、反应温度、反应物配比及催化剂用量对酰化反应的影响。最佳反应条件下乙酰水杨酸收率达94.69%,且催化剂回收容易,重复使用多次仍具有较高活性。 展开更多
关键词 改性固体超强酸 WO3 ZrO2催化剂 乙酰水杨酸 乙酰化反应
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整体式V_2O_5-WO_3/TiO_2-ZrO_2催化剂用于NH_3选择性催化还原NO_x 认领 引用 被引量：10
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作者 李鹏 张亚平 +4 位作者 肖睿 沈凯 孙克勤 徐海涛 周长城 《中南大学学报（自然科学版）》 EI CAS CSCD 北大核心 2013年第4期1719-1726,共8页
通过共沉淀法制备不同锆掺杂量的钛锆复合载体,用分步浸渍法先后浸渍WO3和V2O5得到一系列V2O5-WO3/TiO2-ZrO2催化剂样品,采用X线衍射(XRD)、比表面积测定(BET)、高分辨率透射电子显微镜(HRTEM),程序升温还原(TPR)等表征技术进行相关的... 通过共沉淀法制备不同锆掺杂量的钛锆复合载体,用分步浸渍法先后浸渍WO3和V2O5得到一系列V2O5-WO3/TiO2-ZrO2催化剂样品,采用X线衍射(XRD)、比表面积测定(BET)、高分辨率透射电子显微镜(HRTEM),程序升温还原(TPR)等表征技术进行相关的表征分析,同时在模拟氨气选择性催化还原NOx(NH3-SCR)的反应条件下对催化剂的脱硝反应活性进行考察。研究结果表明:ZrO2含量为50%(摩尔分数)的催化剂具有较好的热稳定性和较宽的活性窗口。模拟烟气中含有0.08%(体积分数)的SO2时,SO2对所研究催化剂的NO脱除具有一定的促进作用。复合载体Ti0.5Zr0.5O2呈无定形态,具有较大的比表面积和孔容,微粒大小均匀,表面分散性良好;WO3和V2O5高度分散在载体的表面;ZrO2的掺入有利于提高催化剂的还原性能。 展开更多
关键词 V2O5 WO3 TiO2-ZrO2 催化还原 抗SO2
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Hydrogen and syngas production from two-step steam reforming of methane over CeO_2-Fe_2O_3 oxygen carrier 认领 引用 被引量：18
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作者 祝星 王华 +2 位作者 魏永刚 李孔斋 程显名 《Journal of Rare Earths》 SCIE EI CAS 2010年第6期907-913,共7页
Two-step steam reforming of methane (SRM) is a novel chemical looping process towards the production of pure hydrogen and syngas (synthesis gas), consisting of a syngas production step and a water-splitting step. Rene... Two-step steam reforming of methane (SRM) is a novel chemical looping process towards the production of pure hydrogen and syngas (synthesis gas), consisting of a syngas production step and a water-splitting step. Renewable energy can be used to drive this process for hydrogen production, especially solar energy. CeO2-Fe2O3 complex oxide oxygen carrier was prepared by the impregnation method and characterized by means of X-ray diffractometer (XRD), Raman spectroscopy (Raman) and hydrogen programmed reduction (H2-TPR). CH4 temperature programmed and isothermal reactions were adopted to test syngas production reactivity, and water splitting reaction was employed to investigate water-splitting activity. Moreover, two-step SRM performance was evaluated by a successive redox cycle. The results showed that CO-uncontaminated H2 and highly selective syngas (with H2/CO ratio close to 2) could be respectively obtained from two steps, and CeFeO3 formation was found in the first redox cycle and proved to be enhanced by the redox treatment. After 10 successive cycles, obvious CeFeO3 phase was detected, which may be responsible for favorable successive redox cycle performances. 展开更多
关键词 two-step steam reforming of methane CeO2-Fe2O3 oxygen carrier redox cycle hydrogen syngas rare earths
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WO_3/ZrO_2固体超强酸改性及在酯化反应中应用研究 认领 引用 被引量：4
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作者 张存 刘涛 +3 位作者 王洪娟 王峰 潘小玉 刘晓勤 《高校化学工程学报》 EI CAS CSCD 北大核心 2012年第6期983-988,共6页
为进一步提高WO3/ZrO2固体超强酸催化活性和稳定性,采用共沉淀法分别制备Ce和Mn改性WO3/ZrO2催化剂。通过XRD、Raman等方法对改性前后催化剂进行表征,由相应图谱分析Ce和Mn引入对催化剂晶型结构和表面性质的影响;并将改性后催化剂用于... 为进一步提高WO3/ZrO2固体超强酸催化活性和稳定性,采用共沉淀法分别制备Ce和Mn改性WO3/ZrO2催化剂。通过XRD、Raman等方法对改性前后催化剂进行表征,由相应图谱分析Ce和Mn引入对催化剂晶型结构和表面性质的影响;并将改性后催化剂用于丙酸和正丁醇的酯化反应考察其催化性能,同时确定合成丙酸正丁酯的最佳工艺条件。结果表明,Ce或Mn的引入能更好地抑制焙烧时ZrO2晶粒长大,使晶粒粒度更加细化,但是没有改变WO3/ZrO2催化剂的物相结构;与WO3/ZrO2相比,Ce或Mn掺杂后催化剂活性明显提高。 展开更多
关键词 固体超强酸 WO3 ZrO2 锰 铈 酯化反应
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Photocatalytic performance of TiO_2 catalysts modified by H_3PW12O40, ZrO_2 and CeO_2 认领 引用 被引量：5
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作者 CAI Tiejun LIAO Yuchao +3 位作者 PENG Zhenshan LONG Yunfei WEI Zongyuan DENG Qian 《Journal of Environmental Sciences》 SCIE EI CAS 2009年第7期997-1004,共8页
The binary composite photo-catalysts CeO2/ZiO2, ZrO2/ZiO2 and the ternary composite photo-catalysts H3PW12040-CeO2/TiO2, H3PW12O40-ZrO2/TiO2 were prepared by sol-gel method. The catalysts were characterized by thermog... The binary composite photo-catalysts CeO2/ZiO2, ZrO2/ZiO2 and the ternary composite photo-catalysts H3PW12040-CeO2/TiO2, H3PW12O40-ZrO2/TiO2 were prepared by sol-gel method. The catalysts were characterized by thermogravimetric-differential thermal analysis （TG-DTA）, scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The photocatalytic elimination of methanol was used as model reaction to evaluate the photocatalytic activity of the composite catalysts under ultraviolet light irradiation. The effects of doped content, activation temperature, time, initial concentration of methanol and gas flow rate on the catalytic activity were investigated. The results showed that after doping a certain amount of CeO2 and ZrO2, crystallization process of TiO2 was restrained, particles of catalysts are smaller and more uniform. Doping ZrO2 not only significantly improved the catalytic activity, but also increased thermal stability. Doping H3PW12O40 alSO enhanced the catalytic activity. The catalytic activities of binary and ternary composite photocatalysts were significantly higher than un-doped TiO2. The dynamics law of photocatalytic reaction over the binary CeO2/TiO2 and ZrO2/TiO2 catalysts has been studied. The activation energy 15.627 and 15.631 kJ/mol and pre-exponential factors 0.5176 and 0.9899 s^-1 over each corresponding catalyst were obtained. This reaction accords to the first order dynamics law. 展开更多
关键词 TiO2 H3PW12O40 ZrO2 CeO2 photocatalytic elimination of methanol
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Y3+和La3+改性对CeO_2(ZrO_2)/TiO_2催化剂脱硝性能的影响 认领 引用 被引量：6
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作者 金奇杰 陶兴军 +2 位作者 潘有春 沈岳松 祝社民 《热力发电》 CAS 北大核心 2018年第2期71-77,共7页
采用溶胶-凝胶法制备Y3+和La3+掺杂CeO_2(ZrO_2)/TiO_2(简称CZT)催化剂,研究Y3+和La3+掺入对其脱硝性能的影响。采用X射线衍射、氮气吸附脱附、氨气程序升温吸附、氢气程序升温还原以及紫外光光致发光光谱等实验方法对CZT... 采用溶胶-凝胶法制备Y3+和La3+掺杂CeO_2(ZrO_2)/TiO_2(简称CZT)催化剂,研究Y3+和La3+掺入对其脱硝性能的影响。采用X射线衍射、氮气吸附脱附、氨气程序升温吸附、氢气程序升温还原以及紫外光光致发光光谱等实验方法对CZT催化剂进行表征。结果表明:Y3+和La3+的掺入抑制了TiO_2从无定形向锐钛矿型转变,不仅增大了催化剂的弱酸酸量和比表面积,同时提高了CZT催化剂的缺陷浓度和储释氧性能;弱酸酸量和比表面积的增大有利于CZT催化剂表面反应气体的吸附;缺陷浓度和储释氧性能的提高加快了吸附在CZT催化剂表面的NO被氧化速率,有利于催化反应的进行。因此,适量掺入Y3+和La3+会明显提升CZT催化剂的低温脱硝活性,拓宽其活性温度窗口。空速71 400 h-1条件下,0.2LaCZT催化剂在200℃的脱硝率达到85.1%,300℃达到最高(96.5%)。 展开更多
关键词 CeO2(ZrO2)/TiO2 脱硝活性 催化剂 酸性位 溶胶-凝胶 La3+ Y3+ 改性
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WO3/ZrO2催化烷烃异构化反应研究进展 认领 引用 被引量：8
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作者 汪颖军 张海菊 +1 位作者 孙博 田性刚 《石油学报（石油加工）》 EI CAS 北大核心 2009年第2期283-290,共8页
介绍了WO3/ZrO2固体超强酸催化剂几种常用的制备方法,概述了制备条件对WO3/ZrO2结构及其对烷烃异构化催化性能的影响,综述了WO3/ZrO2及改性的WO3/ZrO2固体超强酸催化剂催化烷烃异构化反应的研究进展。结果表明,WO3/ZrO2固体超强酸对烷... 介绍了WO3/ZrO2固体超强酸催化剂几种常用的制备方法,概述了制备条件对WO3/ZrO2结构及其对烷烃异构化催化性能的影响,综述了WO3/ZrO2及改性的WO3/ZrO2固体超强酸催化剂催化烷烃异构化反应的研究进展。结果表明,WO3/ZrO2固体超强酸对烷烃异构化反应具有较好的催化性能,催化剂中WO3含量、焙烧温度及ZrO2晶型是影响催化性能的主要因素。还简要介绍了WO3/ZrO2表面结构,预测了WO3/ZrO2固体超强酸催化剂今后的研究重点。 展开更多
关键词 WO3/ZrO2 固体超强酸 异构化 催化剂
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共沉淀法制备的CeO2-ZrO2-Al2O3材料及性能 认领 引用 被引量：11
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作者 李红梅 周菊发 +4 位作者 祝清超 曾少华 魏振玲 陈耀强 龚茂初 《高等学校化学学报》 SCIE CAS 北大核心 2009年第12期2484-2486,共3页
CeO2-based oxygen materials were prepared with co-precipitation method and characterized via Brunauer-Emmet Teller(BET)method,X-ray diffraction(XRD)and temperature-programmed reduction(H2-TPR).This paper revealed that... CeO2-based oxygen materials were prepared with co-precipitation method and characterized via Brunauer-Emmet Teller(BET)method,X-ray diffraction(XRD)and temperature-programmed reduction(H2-TPR).This paper revealed that three CeO2-based oxygen storage materials are all forming homogeneous solid solution.Among the samples,CeO2-ZrO2-Al2O3(CZA)has the best textural properties and excellent thermal stability.The specific surface area and pore volume of aged CZA are 90 m2/g and 0.29 mL/g.We proposed a viewpoint:Al3+ might insert among the interspace of fluorite structure or highly dispersal in solid solutions. 展开更多
关键词 CeO2-ZrO2-Al2O3 共沉淀法 热稳定性能 结构性能 固溶体
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Synthesis of neodymium modified CeO_2-ZrO_2-Al_2O_3 support materials and their application in Pd-only three-way catalysts 认领 引用 被引量：8
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作者 彭娜 周菊发 +3 位作者 陈山虎 罗秀超 陈耀强 龚茂初 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第4期342-349,共8页
Ce-Zr-Al-Nd2O3 （CZAN） support materials were prepared by co-precipitation and impregnation methods, respectively. They were characterized by X-ray diffTaction （XRD）, low temperature nitrogen adsorption-desorption,... Ce-Zr-Al-Nd2O3 （CZAN） support materials were prepared by co-precipitation and impregnation methods, respectively. They were characterized by X-ray diffTaction （XRD）, low temperature nitrogen adsorption-desorption, oxygen pulsing technique, H2-temperamre programmed reduction （H2-TPR） and X-ray photoelectron spectroscopy （XPS）. The Pd-only three-way catalysts （Pd-TWC） supported on these materials were prepared by incipient wetness method and studied by activity tests. The results demonstrated that the CZAN supports obtained by the two methods showed better structural, textural and redox properties than the CZA without Nd2O3, and the addition of Nd203 improved the catalytic activity of TWC. Especially, the CZAN-i support prepared by impregnation method had better thermal stability and redox property. Meanwhile, the Pd/CZAN-i catalyst exhibited the best catalytic performance. XPS measurements indicated that the Nd-modified samples possessed more Ce3＋ and oxygen vacancies on the surface of samples, which led to a better redox property. The excellent redox property of support materials helped to improve the catalytic activity of TWC. 展开更多
关键词 CeO2-ZrO2-Al2O3 support materials Nd2O3 Ce-O-Nd bonds Pd-only three-way catalysts redox property rare earths
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不同铈添加量对CeO_2-ZrO_2-Al_2O_3材料性能的影响 认领 引用 被引量：8
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作者 唐石云 焦毅 +4 位作者 李小双 王云 王键礼 龚茂初 陈耀强 《无机化学学报》 SCIE CAS CSCD 北大核心 2012年第5期965-970,共6页
采用共沉淀法制备了一系列不同铈添加量的CeO2-ZrO2-Al2O3(CZA)储氧材料,并通过XRD、低温N2吸附-脱附、氧脉冲吸附(OSC)和H2-TPR等手段进行了表征。XRD结果表明,在1 000和1 100℃高温焙烧后,当CeO2添加量为8%时样品具有最好的结构稳定... 采用共沉淀法制备了一系列不同铈添加量的CeO2-ZrO2-Al2O3(CZA)储氧材料,并通过XRD、低温N2吸附-脱附、氧脉冲吸附(OSC)和H2-TPR等手段进行了表征。XRD结果表明,在1 000和1 100℃高温焙烧后,当CeO2添加量为8%时样品具有最好的结构稳定性能。N2吸附-脱附结果表明,CeO2添加量为8%时样品具有最好的织构性能,1 000℃时,比表面积和孔容分别为:136.6 m2.g-1和0.38 mL.g-1;1 100℃时,比表面积和孔容分别为:83.7 m2.g-1和0.23 mL.g-1。OSC结果显示,CeO2添加量为8%时样品具有最大的储氧量,1 000℃和1 100℃分别为70μmol.g-1和31μmol.g-1。H2-TPR结果表明,CeO2添加量为8%时样品具有最佳的还原性能。 展开更多
关键词 CeO2-ZrO2-Al2O3 结构性能 储氧性能 还原性能
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水蒸汽对Ni/CeO_2-ZrO_2-Al_2O_3催化剂上CO_2+CH_4重整反应的影响 认领 引用 被引量：11
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作者 李春林 伏义路 +4 位作者 孟明 卞国柱 谢亚宁 胡天斗 张静 《Chinese Journal of Chemical Physics》 SCIE CAS 北大核心 2004年第1期95-99,共5页
用水热合成法制备了Ni/CeO2 ZrO2 Al2 O3 催化剂 .进行了添加和不添加水蒸汽的CH4 +CO2 催化重整反应 ,测试了活性和稳定性 ,测量了积碳量 ,并用XAFS手段测试了催化剂Ni的K吸收边 .结果表明 ,在反应过程中有CeAlO3 的生成 ,但积碳是无... 用水热合成法制备了Ni/CeO2 ZrO2 Al2 O3 催化剂 .进行了添加和不添加水蒸汽的CH4 +CO2 催化重整反应 ,测试了活性和稳定性 ,测量了积碳量 ,并用XAFS手段测试了催化剂Ni的K吸收边 .结果表明 ,在反应过程中有CeAlO3 的生成 ,但积碳是无水蒸汽添加的反应活性降低的原因 .反应气中添加水蒸汽能够减少积碳 ,从而提高催化反应的稳定性 .由于碳原子插入Ni晶格 ,无水蒸汽反应后的最近邻Ni Ni配位数有较大幅度的减少 .添加了水蒸汽的反应 ,最近邻Ni Ni配位数比反应前减少幅度小 ,这主要是由于在反应气中添加水蒸汽减少了积碳 。 展开更多
关键词 CO2+CH4重整反应 添加水蒸汽 Ni/CeO2-ZrO2-Al2O3催化剂 XAFS 积碳
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