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Ca and Sr co-doping induced oxygen vacancies in 3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts for boosting low-temperature oxidative coupling of methane
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作者 Tongtong Wu Yuechang Wei +5 位作者 Jing Xiong Yitao Yang Zhenpeng Wang Dawei Han Zhen Zhao Jian Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期331-344,共14页
It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(... It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(A_(2)B_(2)O_(7)-type)catalysts with disordered defective cubic fluorite phased structure were successfully prepared by a colloidal crystal template method.3DOM structure promotes the accessibility of the gaseous reactants(O2and CH4)to the active sites.The co-doping of Ca and Sr ions in La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts improved the formation of oxygen vacancies,thereby leading to increased density of surface-active oxygen species(O_(2)^(-))for the activation of CH4and the formation of C2products(C2H6and C2H4).3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts exhibit high catalytic activity for OCM at low temperature.3DOM La1.7Sr0.3Ce1.7Ca0.3O7-δcatalyst with the highest density of O_(2)^(-)species exhibited the highest catalytic activity for low-temperature OCM,i.e.,its CH4conversion,selectivity and yield of C2products at 650℃are 32.2%,66.1%and 21.3%,respectively.The mechanism was proposed that the increase in surface oxygen vacancies induced by the co-doping of Ca and Sr ions boosts the key step of C-H bond breaking and C-C bond coupling in catalyzing low-temperature OCM.It is meaningful for the development of the low-temperature and high-efficient catalysts for OCM reaction in practical application. 展开更多
关键词 3DOM catalysts Ca ions Sr ions Low-temperature oxidative couplingof methane Oxygen vacancies O_(2)^(-) species
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Propene and CO oxidation on Pt/Ce-Zr-SO_4^(2-) diesel oxidation catalysts:Effect of sulfate on activity and stability 被引量:9
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作者 顾蕾 陈晓 +3 位作者 周瑛 朱秋莲 黄海凤 卢晗锋 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第3期607-616,共10页
Platinum/cerium-zirconium-sulfate(Pt/Ce-Zr-SO_4^(2-)) catalysts were prepared by wetness impregnation.Catalytic activities were evaluated from the combustion of propene and CO.Sulfate(SO_4^(2-))addition improv... Platinum/cerium-zirconium-sulfate(Pt/Ce-Zr-SO_4^(2-)) catalysts were prepared by wetness impregnation.Catalytic activities were evaluated from the combustion of propene and CO.Sulfate(SO_4^(2-))addition improved the catalytic activity significantly.When using Pt/Ce-Zr-SO_4^(2-) with 10 wt%SO_4^(2-),the temperature for 90%conversion of propene and CO decreased by 75℃ compared with Pt/Ce-Zr.The conversion exceeded 95%at 240℃ even after 0.02%sulfur dioxide poisoning for 20 h.Temperature-programmed desorption of CO and X-ray photoelectron spectroscopy analyses revealed an improvement in Pt dispersion onto the Ce-Zr-SO_4^(2-) support,and the increased number of Pt particles built up more Pt^(-)-(SO_4^(2-))^(-) couples,which resulted in excellent activity.The increased total acidity and new Bronsted acid sites on the surface provided the Pt/Ce-Zr-SO_4^(2-) with good sulfur resistance. 展开更多
关键词 Diesel oxidation catalyst Pt/Ce-Zr-SO_4^(2- catalyst Sulfur resistance Catalytic oxidation
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LCC-2催化剂高温催化裂解制低碳烯烃的反应性能 被引量:2
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作者 樊江涛 侯凯军 +2 位作者 田爱珍 王智峰 张海涛 《石油学报(石油加工)》 EI CAS CSCD 北大核心 2010年第S1期98-101,共4页
以重油催化裂化装置原料油为原料,在固定流化床催化裂化试验装置上评价了LCC-2催化剂的反应性能。结果表明,反应温度升高时,汽油、柴油和重油收率逐渐下降,干气和焦炭产率逐渐增加;液化气收率先升高后降低,590℃时达到最大值;乙烯收率... 以重油催化裂化装置原料油为原料,在固定流化床催化裂化试验装置上评价了LCC-2催化剂的反应性能。结果表明,反应温度升高时,汽油、柴油和重油收率逐渐下降,干气和焦炭产率逐渐增加;液化气收率先升高后降低,590℃时达到最大值;乙烯收率逐渐增加,但丙烯和丁烯收率先升高后降低,均在620℃达到最大值。当反应温度为560~590℃时,低碳烯烃总收率最高可达到23.93%,液化气+汽油+柴油总收率最高为81.35%,干气、重油和焦炭的产率相对较低,产物分布较好。 展开更多
关键词 催化裂解 反应温度 重油 低碳烯烃 lcc-2催化剂
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Preparation,characterization and catalytic properties of S_2O_8^(2-)/ZrO_2-CeO_2 solid superacid catalyst 被引量:25
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作者 樊国栋 沈茂 +1 位作者 张昭 贾发瑞 《Journal of Rare Earths》 SCIE EI CAS CSCD 2009年第3期437-442,共6页
A novel solid superacid catalyst S2O8^2-/ZrO2-CeO2 was prepared by a coprecipitation method and characterized by means of XRD FTIR, BET, TEM and DSC/TG analysis methods. The results indicated that incorporation of app... A novel solid superacid catalyst S2O8^2-/ZrO2-CeO2 was prepared by a coprecipitation method and characterized by means of XRD FTIR, BET, TEM and DSC/TG analysis methods. The results indicated that incorporation of appropriate amounts of Ce into the catalyst was beneficial to the formation of sole tetragonal ZrO2 and effectively prevented from the formation of monoclinic ZrO〉 and restrained the loss of sulfated species. XRD revealed the presence of tetragonal Ce0.16Zr0.84O2phase in the case of S2O8^2-/ZrO2-CeO2 calcined above 500 ℃. Catalytic activities of S2O8^2-/ZrO2-CeO2 for the esterification of lactic acid with n-butanol was studied. The results showed that the optimum conditions were as follows: calcination temperature of the catalyst 600 ℃, n(lactic acid):n(n-butyl alcohol)=1.0:3.0, w(S2O8^2-/ZrO2- CeO2)=12.0%, reaction temperature 145 ℃, and reaction time 2 h. The esterification efficiency of lactic acid was about 96.6%. 展开更多
关键词 solid superacid catalyst S2O8^2-/ZrO2-CeO2 n-butyl lactate ESTERIFICATION rare earths
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反应温度对LCC-2催化剂催化裂解制低碳烯烃性能的影响 被引量:4
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作者 侯凯军 樊江涛 +3 位作者 田爱珍 王林 孙雪芹 王智峰 《石化技术与应用》 CAS 2011年第1期17-20,共4页
以中国石油大庆炼化公司重油催化裂化装置所用原料油为原料,在固定流化床催化裂化试验装置上评价了LCC-2型催化剂的反应性能。结果表明,反应温度升高时,汽油、柴油和重油收率逐渐下降,干气和焦炭收率逐渐增加;液化气收率先升高后降低,59... 以中国石油大庆炼化公司重油催化裂化装置所用原料油为原料,在固定流化床催化裂化试验装置上评价了LCC-2型催化剂的反应性能。结果表明,反应温度升高时,汽油、柴油和重油收率逐渐下降,干气和焦炭收率逐渐增加;液化气收率先升高后降低,590℃时达到最大值;乙烯收率逐渐增加,但丙烯和丁烯收率先升高后降低,均在620℃达到最大值。当反应温度为560~590℃时,低碳烯烃总收率最高可达到23.93%,液化气、汽油和柴油总收率最高为81.35%,干气、重油和焦炭的产率相对较低,产物分布较好。 展开更多
关键词 催化裂解 反应温度 重油 低碳烯烃 lcc-2催化剂
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LCC-2催化剂在重油催化裂化装置的应用 被引量:1
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作者 唐家俊 吴隆庆 李峰 《石化技术与应用》 CAS 2008年第4期336-339,共4页
介绍了LCC-2多产丙烯催化剂在中国石油大连石化公司140万t/a催化装置改造中的应用情况。标定结果表明,应用LCC-2催化剂后,液化气产率由13.76%增加到22.99%,其所含丙烯由35.13%增加到47.77%。生产统计结果表明:装置加工量按150万t/a计算... 介绍了LCC-2多产丙烯催化剂在中国石油大连石化公司140万t/a催化装置改造中的应用情况。标定结果表明,应用LCC-2催化剂后,液化气产率由13.76%增加到22.99%,其所含丙烯由35.13%增加到47.77%。生产统计结果表明:装置加工量按150万t/a计算,改造后丙烯产率由5.10%增加到6.99%,丙烯产量增加2.835万t/a;可增效约8 000万元/a,实现了装置增产增效的预期目的。 展开更多
关键词 重油催化裂化 lcc-2催化剂 丙烯 液化气 增产增效 应用
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Ce_xTi_(1-x)O_2 Mixed Oxides Supported CuO Catalyst for NO Reduction by CO 被引量:1
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作者 楼莉萍 蒋晓原 +3 位作者 陈英旭 吕光烈 周仁贤 郑小明 《Journal of Rare Earths》 SCIE EI CAS CSCD 2003年第3期331-336,共6页
Ce x Ti 1- x O 2 mixed oxides of different mole ratios ( x =0, 0.1, 0.2~0.9, 1.0) were prepared by co precipitation of TiCl 4 with Ce(NO 3) 3 and then loaded with different amounts of CuO. The effe... Ce x Ti 1- x O 2 mixed oxides of different mole ratios ( x =0, 0.1, 0.2~0.9, 1.0) were prepared by co precipitation of TiCl 4 with Ce(NO 3) 3 and then loaded with different amounts of CuO. The effects of CuO on NO+CO reaction were investigated, and the structure and reductive properties of various CuO/Ce x Ti 1- x O 2 were characterized by the methodologies of BET, TPR and XRD. The results show that different Ce/Ti mole ratios and calcination temperatures induce changes of structure and reductive properties of the Ce x Ti 1- x O 2 mixed oxides. When x =0.1~0.5, amorphous CeTi 2O 6 phase mainly forms at 650 ℃ compared to the formation of CeTi 2O 6 which crystallizes at 800 ℃. When x >0.6, some TiO 2 enters the CeO 2 lattice and a CeO 2 TiO 2 solid solution is formed. The activity of 6%CuO/Ce x Ti 1- x O 2 calcined at 650 ℃ is largely affected by the x values, which is the highest when x =0.3, 0.4 and 0.9. The NO conversion reaches 70% at a reaction temperature of 150 ℃. By comparison, the x values have little effect on the activity of 6%CuO/Ce x Ti 1- x O 2 calcined at 800 ℃ . There are strong interactions between CuO and CeTi 2O 6, i.e., formation of the CeTi 2O 6 phase shifts the CuO reduction peak temperature from 380 to 200 ℃, and CuO, in turn, shifts the CeTi 2O 6 reduction peak temperature from 600 to 300 ℃. 展开更多
关键词 catalitic chemistry Ce x Ti 1- x O 2 mixed oxides CuO/Ce x Ti 1- x O 2 catalysts CeTi 2O 6 phase NO+CO reaction activity rare earths
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LCC-2多产液态烃催化剂的工业应用
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作者 曹万银 陈家钦 +1 位作者 彭震宇 张林生 《工业催化》 CAS 2010年第6期37-39,共3页
介绍了LCC-2催化剂在广西东油沥青有限公司催化裂化装置上的应用情况。工业标定结果表明,该催化剂在高含重金属镍的催化原料条件下,提高液态烃收率4.32%,催化裂化转化率达77%,选择性能较好,干气、油浆和焦炭收率分别为3.96%、2.21%和8.8... 介绍了LCC-2催化剂在广西东油沥青有限公司催化裂化装置上的应用情况。工业标定结果表明,该催化剂在高含重金属镍的催化原料条件下,提高液态烃收率4.32%,催化裂化转化率达77%,选择性能较好,干气、油浆和焦炭收率分别为3.96%、2.21%和8.87%,但催化剂抗重金属性和耐磨性能不够理想,有待进一步改进。 展开更多
关键词 石油化学工程 催化裂化 液化石油气 lcc-2催化剂 重金属
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Synthesis of 3-(1-Cyclohexenyl)-2-butanone via Environmentally Friendly Catalysts
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作者 ZHAO Zhen-hua 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2003年第3期350-354,共5页
We substituted several environmentally friendly catalysts which included HY and H- β zeolites, various cation-exchanged β zeolites, and solid-supported ferric chloride for conventional catalysts for the synth... We substituted several environmentally friendly catalysts which included HY and H- β zeolites, various cation-exchanged β zeolites, and solid-supported ferric chloride for conventional catalysts for the synthesis of 3-(1-cyclohexenyl)-2-butanone from the reaction of ethylidenecyclohexane with acetic anhydride at room temperature. HY zeolite was found to be the most effective for this reaction, and gave the acylated product in a 72% yield under the conditions of n (ethylidenecyclohexane)/ n (acetic anhydride)/ m (HY zeolite)=1 mmol/10 mmol/0 100 g, reaction temperature 25 ℃ and reaction time 2 h. The used HY zeolite can be recovered, regenerated and gave almost the same yield as the fresh one. The lifetime of the HY zeolite is over 80 h. The effect of different factors on the reaction has also been investigated. 展开更多
关键词 ACYLATION ZEOLITE Environmentally friendly catalyst 3-(1-Cyclohexenyl)-2-butanone Ethylidenecyclohexane Acetic anhydride Synthesis
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PREPARATION,CHARACTERIZATION AND HYDROGENATION PROPERTY OF POLYMER-SUPPORTED Pd-Fe_2O_3 COMPOSITE CATALYSTS
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作者 ZHANG Shengmin HU Weibing ZHANG Manzheng Wuhan University of Technology Hubei Research Institute of Chemistry 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1999年第4期48-52,共5页
A series of polymer- supported Pd -Fe2O3 composite catalysts were prepared and their hydrogenation property mas investigated. It was found that the above catalysts have good catalytic hydrogenation activity for carbon... A series of polymer- supported Pd -Fe2O3 composite catalysts were prepared and their hydrogenation property mas investigated. It was found that the above catalysts have good catalytic hydrogenation activity for carbon - carbon double bonds systems and reusability. Furthermore, XPS and IR spectra shouted that active component in the composite catalysts is atomic Pd(0). An addition of a small amount of Fe2O3 has a promotive action upon hydrogenation activity of the catalysts, which indicated that there are some strong interactions (electron transfer) between Pd(0) and Fe(Ⅲ) species. Based on these results, a possible catalytic hydrogenation mechanism was also suggested. 展开更多
关键词 functional material polymet-sup- ported catalyst composite Pd - F2O3/polystyrene HYDROGENATION mechanism
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CATALYTIC PERFORMANCE OF ETHYLENE HYDROFORMYLATION OVER[H_XRu_3(CO)_9(CCO)]^(2-X)/SiO_2-Al_2O_3,SiO_2 AND MgO(X=0-2)CATALYSTS
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作者 Feng Shou XIAO RuRen XU (Department of Chemistry,Jilin University,Changchun 130023)Masaru ICHIKAWA (Catalysis Research Center,Hokkaido University,Sapporo 060,Japan)Duward F.SHRIVER (Department of Chemistry,Northwestern University,Evanston,IL 602083113,USA)Xie Xian GUO (National Laboratory for Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dilian 116023,) 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第7期579-580,共2页
The various surface species[H_XRu_3(CO)_9(CCO)]^(2-X)(X=0-2)prepared from impregnation of[PPN]_2[Ru_3(CO)_9(CCO)]on SiO_2-Al_2O_3,SiO_2 and MgO show quite different activities and selectivities for oxygenates and etha... The various surface species[H_XRu_3(CO)_9(CCO)]^(2-X)(X=0-2)prepared from impregnation of[PPN]_2[Ru_3(CO)_9(CCO)]on SiO_2-Al_2O_3,SiO_2 and MgO show quite different activities and selectivities for oxygenates and ethane in ethylene hydroformylation. 展开更多
关键词 CCO X=0-2)catalystS CATALYTIC PERFORMANCE OF ETHYLENE HYDROFORMYLATION OVER[HXRu3 X SiO2-Al2O3 SiO2 AND MgO MGO Al
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A Novel Way to Prepareγ-A1_2O_3 Supported SO_4^(2-)/ZrO_2 Solid Superacid Catalysts for n-Butane Isomerization
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作者 Ting LEI Yi TANG +2 位作者 Wei Ming HUA Jin Suo XU Zi GAO (Department of Chemistry, Fudan University, Shanghai 200433) 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第1期89-92,共4页
Highly active solid superacid catalysts for n-butane isomerization, SZ/A1_2O_3-P, were prepared by supporting SO-(4-2)/ZrO2, (SZ) on y-A1_2O_3 carrier using a precipitation method. The activities of some catalysts wer... Highly active solid superacid catalysts for n-butane isomerization, SZ/A1_2O_3-P, were prepared by supporting SO-(4-2)/ZrO2, (SZ) on y-A1_2O_3 carrier using a precipitation method. The activities of some catalysts were enhanced significantly j The activity of the most active sample. 60%SZ/Al_2O3-P, was even about 2 times more active than that of the SZ catalyst. 展开更多
关键词 SO_4^(2-)/ZrO_2 n-Butane Isomerization γ-A1_2O_3 supported superacid catalysts.
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Quaternary phosphonium polymer-supported dual-ionically bound[Rh(CO)I_(3)]^(2-)catalyst for heterogeneous ethanol carbonylation
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作者 Zhou Ren Yang Liu +4 位作者 Yuan Lyu Xiangen Song Changyong Zheng Zheng Jiang Yunjie Ding 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第4期606-617,共12页
A single-Rh-site catalyst(Rh-TPISP)that was ionically-embedded on a P(V)quaternary phosphonium porous polymer was evaluated for heterogeneous ethanol carbonylation.The[Rh(CO)I_(3)]^(2-)unit was proposed to be the acti... A single-Rh-site catalyst(Rh-TPISP)that was ionically-embedded on a P(V)quaternary phosphonium porous polymer was evaluated for heterogeneous ethanol carbonylation.The[Rh(CO)I_(3)]^(2-)unit was proposed to be the active center of Rh-TPISP for the carbonylation reaction based on detailed Rh L3-edge X-ray absorption near edge structure(XANES),X-ray photoelectron spectroscopy(XPS),and Rh extended X-ray absorption fine structure(EXAFS)analyses.As the highlight of this study,Rh-TPISP displayed distinctly higher activity for heterogeneous ethanol carbonylation than the reported catalytic systems in which[Rh(CO)_(2)I_(2)]^(-)is the traditional active center.A TOF of 350 h^(-1)was obtained for the reaction over[Rh(CO)I_(3)]^(2-),with>95%propionyl selectivity at 3.5 MPa and 468 K.No deactivation was detected during a near 1000 h running test.The more electron-rich Rh center was thought to be crucial for explaining the superior activity and selectivity of Rh-TPISP,and the formation of two ionic bonds between[Rh(CO)I_(3)]^(2-)and the cationic P(V)framework([P]^(+))of the polymer was suggested to play a key role in firmly immobilizing the active species to prevent Rh leaching. 展开更多
关键词 Heterogeneous ethanol carbonylation Single-site catalyst Carbonylation active center [Rh(CO)I_(3)]^(2-) Ultrastable dual-ionically bound immobilization Porous ionic polymer
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Effect of TiO_2 surface properties on the SCR activity of NOx emission abatement catalyst 被引量:4
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作者 YEDai-qi TIANLiu-qing LIANGHong 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2002年第4期530-535,共6页
NOx emission abatement catalysts V 2O 5 supported on various TiO 2 including anatase, rutile and mixture of both were investigated with various physico\|chemical measurements such as BET, NH\-3\|TPD, NARP, XRD and ... NOx emission abatement catalysts V 2O 5 supported on various TiO 2 including anatase, rutile and mixture of both were investigated with various physico\|chemical measurements such as BET, NH\-3\|TPD, NARP, XRD and so on, and the effect of TiO\-2 surface properties on the SCR(selective catalytic reduction) activity of V\-2O\-5/TiO\-2 catalysts was studied. It was found that the TiO\-2 surface properties had strong affect on the SCR activity of V\-2O\-5/TiO\-2 catalysts. The stronger acidic property resulted in the higher exposure of active sites as well as the higher SCR activity. 展开更多
关键词 NOx SCR(selective catalytic reduction) surface acidity V\-2O\-5/TiO\-2 catalyst
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Synthesis, Structure and Catalytic Activity of a Manganese(Ⅲ) Complex Based on 2-(2-Hydroxyphenyl)-5,6-dichlorobenzimidazole Ligands 被引量:2
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作者 王鸾 张纯喜 赵井泉 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第10期1479-1487,共9页
A new ligand, 2-(2-hydroxyphenyl)-5,6-dichlorobenzimidazole, H2pbmCl2(1), and a novel MnIII complex, [MnIII(HpbmCl2)(pbmCl2)(DMF)2](2),(DMF = N,N-dimethylformamide), have been synthesized and characteriz... A new ligand, 2-(2-hydroxyphenyl)-5,6-dichlorobenzimidazole, H2pbmCl2(1), and a novel MnIII complex, [MnIII(HpbmCl2)(pbmCl2)(DMF)2](2),(DMF = N,N-dimethylformamide), have been synthesized and characterized. The crystal of compound 1(C13H8Cl2N2O, Mr = 279.12) belongs to the monoclinic system, space group P21 with a = 3.770(5), b = 25.20(3), c = 5.865(7) A, = 92.727(17)o, V = 556.6(12) A3, Z = 2, Dc = 1.665 g/cm^3, S = 1.137, μ= 0.568 mm^-1, F(000) = 284, the final R = 0.0876 and wR = 0.2334 for 1848 independent reflections. The molecule is planar due to the presence of a strong intramolecular hydrogen bond between O–H group of phenol and N atom of imidazole. H2pbmCl2(1) molecules are arranged into a one-dimensional linear chain through intermolecular hydrogen bonds(N–H…O and C–H…Cl). The crystal of complex 2(C32H27Cl4MnN6O4, Mr = 756.34) belongs to the monoclinic system, space group P21/c with a = 19.043(10), b = 10.808(5), c = 18.704(11)A, β= 115.540(6)°, V = 3473(3) A3, Z = 4, Dc = 1.446 g/cm^3, S = 1.3, μ = 0.733 mm-1, F(000) = 1544, the final R = 0.1219 and wR = 0.2681 for 7811 independent reflections. The Mn ion adopts a distorted octahedral geometry coordinated by two deprotonated H2pbmCl2 ligands and two DMF molecules. The [MnIII(HpbmCl2)(pbmCl2)(DMF)2] molecules are arranged into a three-dimensional structure through hydrogen bonds(N–H…N, C–H…N and C–H…Cl) and weak π···πinteractions. The activity measurements suggest that complex 2 is able to serve as a catalyst for H2O2 disproportionation reaction to form O2 in neutral water solution. 展开更多
关键词 2-2-hydroxyphenyl)-5 6-dichlorobenzimidazole manganese complex crystal structure H2O2 disproportionation reaction catalyst
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Stable CuO/La_(2)Sn_(2)O_(7) catalysts for soot combustion:Study on the monolayer dispersion behavior of CuO over a La_(2)Sn_(2)O_(7) pyrochlore support 被引量:2
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作者 Xiaohui Feng Rui Liu +6 位作者 Xianglan Xu Yunyan Tong Shijing Zhang Jiacheng He Junwei Xu Xiuzhong Fang Xiang Wang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第3期396-408,共13页
To understand the dispersion behavior of metal oxides on composite oxide supports and with the expectation of developing more feasible catalysts for soot oxidation,CuO/La_(2)Sn_(2)O_(7)samples containing varied CuO lo... To understand the dispersion behavior of metal oxides on composite oxide supports and with the expectation of developing more feasible catalysts for soot oxidation,CuO/La_(2)Sn_(2)O_(7)samples containing varied CuO loadings were fabricated and characterized by different techniques and density functional theory calculations.In these catalysts,a spontaneous dispersion of CuO on the La_(2)Sn_(2)O_(7)pyrochlore support formed,having a monolayer dispersion capacity of 1.90 mmol CuO/100 m^(2) La_(2)Sn_(2)O_(7)surface.When loaded below this capacity,CuO exists in a sub-monolayer or monolayer state.X-ray photoelectron spectroscopy(XPS),Raman spectroscopy,and Bader charge and density of states analyses indicate that there are strong interactions between the sub-monolayer/monolayer CuO and the La_(2)Sn_(2)O_(7)support,mainly through the donation of electrons from Cu to Sn at the B-sites of the structure.In contrast,Cu has negligible interactions with La at the A-sites.This suggests that,in composite oxide supports containing multiple metals,the supported metal oxide interacts preferentially with one kind of metal cation in the support.The Raman,in situ diffuse reflectance infrared Fourier transform spectroscopy,and XPS results confirmed the formation of both O2^(-)and O2^(2-)as the active sites on the surfaces of the CuO/La_(2)Sn_(2)O_(7)catalysts,and the concentration of these active species determines the soot combustion activity.The number of active oxygen anions increased with increase in CuO loading until the monolayer dispersion capacity was reached.Above the monolayer dispersion capacity,microsized CuO crystallites formed,and these had a negative effect on the generation of active surface oxygen sites.In summary,a highly active catalyst can be prepared by covering the surface of the La_(2)Sn_(2)O_(7)support with a CuO monolayer. 展开更多
关键词 CuO/La_(2)Sn_(2)O_(7)catalyst Soot combustion DFT calculations Preferential interaction Monolayer dispersion on pyrochlore support Active O2^(-)and O2^(2-)sites
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Catalytic Synthesis of Isopropyl Benzene over SO_4 ^(2-)/ZrO_ 2-MCM-41 被引量:1
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作者 WEI Chang-ping LI Shu-zeng +2 位作者 ZHOU Bin PENG Chun-jia ZHEN Kai-ji 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2006年第3期371-374,共4页
Super acid catalyst SO4^2-/ZrO2 was introduced into pure silicone MCM-41 via the impregnation method and the catalyst samples obtained at different temperatures were characterized by means of XRD, IR, and Py-IR techni... Super acid catalyst SO4^2-/ZrO2 was introduced into pure silicone MCM-41 via the impregnation method and the catalyst samples obtained at different temperatures were characterized by means of XRD, IR, and Py-IR techniques. The selectively catalytic gas-phase flow reactions of benzene with propene over the catalyst samples were carried out in a made-to-measure high-pressure flow reactor equipped with a thermostat and a condenser. Effect of the preparative condition on the catalytic synthesis of isopropyl benzene over the catalyst samples was tested. The results show that SO4^2-/ZrO2-MCM-41 ( SZM-41 ) can be used as a catalyst for the title reaction, in which there are a higher conversion (97%) for the propene and a higher selectivity(93% ) for the isopropyl benzene. 展开更多
关键词 BENZENE PROPENE Isopropyl benzene SO4^2-/ZrO2-MCM-41 catalyst
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Mechanistic Investigation on Rhodium(III)-Catalyzed Cycloaddition of 2-Vinylphenol Derivatives with Ethyne or Carbon Monoxide by DFT Study 被引量:1
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作者 Xing-hui Zhang Xi Wu Hai-xiong Shi 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第4期685-696,I0091-I0136,I0150,共59页
Rhodium-catalyzed cycloaddition reaction was calculated by density functional theory M06-2X method to directly synthesize benzoxepine and coumarin derivatives.In this work,we conducted a computational study of two com... Rhodium-catalyzed cycloaddition reaction was calculated by density functional theory M06-2X method to directly synthesize benzoxepine and coumarin derivatives.In this work,we conducted a computational study of two competitive mechanisms in which the carbon atom of acetylene or carbon monoxide attacked and inserted from two different directions of the six-membered ring reactant to clarify the principle characteristics of this transformation.The calculation results reveal that:(i)the insertion process of alkyne or carbon monoxide is the key step of the reaction;(ii)for the(5+2)cycloaddition reaction of acetylene,higher energy is required to break the Rh−O bond of the reactant,and the reaction tends to complete the insertion from the side of the Rh−C bond;(iii)for the(5+1)cycloaddition of carbon monoxide,both reaction paths have lower activation free energy,and the two will generate a competition mechanism. 展开更多
关键词 Rhodium catalyst Cycloaddition reaction Benzoxepine derivatives Density functional theory M06-2X
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3D layer-by-layer amorphous MoS_(x) assembled from[Mo_(3)S_(13)]^(2-)clusters for efficient removal of tetracycline:Synergy of adsorption and photo-assisted PMS activation
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作者 Yue Li Minghao Fan +7 位作者 Conghui Wang Yanxun Li Xiang Yu Jun Ding Lei Yan Lele Qiu Yongcai Zhang Longlu Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第9期369-375,共7页
Peroxymonosulfate(PMS)activation and photocatalysis are effective technologies to remove organic pollutants,but the adsorption effect of the catalyst is usually unheeded in degradation process.Herein,a bifunctional ca... Peroxymonosulfate(PMS)activation and photocatalysis are effective technologies to remove organic pollutants,but the adsorption effect of the catalyst is usually unheeded in degradation process.Herein,a bifunctional catalyst of amorphous MoS_(x)(a-MoS_(x))with 3D layer-by-layer superstructure was synthesized by assembling basic active units[Mo_(3)S_(13)]^(2-)of MoS_(2).The large interlayer spacing and high exposure of active sites render a-MoS_(x)to have excellent synergy of adsorption and photo-assisted PMS activation for tetracycline(TC)degradation.Experiments and DFT calculation show that TC can be efficiently enriched on a-MoS_(x)by pore filling,π-πinteraction,hydrogen bonding and high adsorption energy.Subsequently,PMS can be quickly activated through electron transfer with a-MoS_(x),resulting in high TC degradation efficiency of 96.6%within 20 min.In addition,the synergistic mechanism of adsorption and photo-assisted PMS activation was explored,and the degradation pathway of TC was expounded.This work is inspirational for constructing bifunctional catalysts with superior synergistic adsorption and catalytic capabilities to remove refractory organic pollutants in water. 展开更多
关键词 Bifunctional catalyst [Mo_(3)S_(13)]^(2-) ADSORPTION Photo-assisted PMS activation Active sites
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Surface and Texture Properties of Tb-Doped Ceria-Zirconia Solid Solution Prepared by Sol-Gel Method 被引量:6
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作者 樊国栋 冯长根 张昭 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第1期42-47,共6页
The three-way catalysts (TWCs) promoters Ce0.6Zr0.4- x TbxO2-y were prepared by sol-gel method. BET surface areas analysis indicated that an increase of the dopant Tb content from x = 0.05 to x = 0.15 favors an incr... The three-way catalysts (TWCs) promoters Ce0.6Zr0.4- x TbxO2-y were prepared by sol-gel method. BET surface areas analysis indicated that an increase of the dopant Tb content from x = 0.05 to x = 0.15 favors an increase of surface area from 66.8 to 80.4 m^2· g^-1 compared with the undoped sample Ce0 .6oZr0.40O2 65.1 m^2·g^- 1 after calcination at 650℃. Transmission electron microscopy (TEM) observation indicated that the doped samples have a higher thermal stability. The XRD and Raman spectra confirmed that the Ce0.6Zr0.4-xTbxO2-y cubic solid solution is formed. XPS analysis revealed that Ce and Tb mainly existed in the form of Ce^4+ and Tb^3 + , and Zr existed in the form of Zr^4+ on the surface of the samples. The doped samples were homogenous in composition ; the introduction of Tb into the CeO2-ZrO2 promoters resuited in the formation of a solid solution, and the concentration of surface lattice oxygen was increased. 展开更多
关键词 Ce0.6Zr0.4 - xTbxO2 - y solid solution three-way catalysts sol-gel method surface and texture structure rare earths
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