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Effect of active oxygen on the performance of Pt/CeO2 catalysts for CO oxidation 认领 引用 被引量：19
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作者 Anbin Zhou Jun Wang +3 位作者 Hui Wang Hang Li Jianqiang Wang Meiqing Shen 《Journal of Rare Earths》 SCIE EI CAS CSCD 2018年第3期257-264,共8页
This study was focused on the influence of active oxygen on the performance of Pt/CeO2 catalysts for CO oxidation. A series of CeO2 supports with different contents of active oxygen were obtained by adding surfactant ... This study was focused on the influence of active oxygen on the performance of Pt/CeO2 catalysts for CO oxidation. A series of CeO2 supports with different contents of active oxygen were obtained by adding surfactant at different synthesis steps. 0.25 wt% Pt was loaded on these CeO2 supports by incipientwetness impregnation methods. The catalysts were characterized by N2 adsorption, X-ray diffraction（XRD）, high-resolution transmission electron microscopy（HRTEM）, H2 temperature-programmed reduction（H2-TPR）, dynamic oxygen storage capacity（DOSC） and in-situ DRIFTS technologies. For S-f supports, the surfactant was added into the solution before spray-drying in the synthesis process, which facilitates more active oxygen formation on the surface of CeO2. After loading Pt, the more active oxygen on CeO2 contributes to dispersing Pt species and enhancing the CO oxidation activity. As for the aged samples,Pt-R-h shows the highest activity above 190 ℃ because of the presence of more partly oxidized Pt^（δ＋） species. Thus the activity is also influenced by the states of Pt and the Pt^（δ＋） species may contribute to the high activity at elevated temperature. 展开更多
关键词 CeO2 Active oxygen Pt/CeO2 catalyst Pt dispersion CO oxidation Rare earths
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Size-dependent strong metal-support interaction modulation of Pt/CoFe2O4 catalysts 认领 引用 被引量：1
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作者 Yangyang Li Jingyi Yang +1 位作者 Botao Qiao Tao Zhang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2025年第2期292-302,共11页
Supported metal catalysts are the backbone of heterogeneous catalysis,playing a crucial role in the modern chemical industry.Metal-support interactions(MSIs)are known important in determining the catalytic performance... Supported metal catalysts are the backbone of heterogeneous catalysis,playing a crucial role in the modern chemical industry.Metal-support interactions(MSIs)are known important in determining the catalytic performance of supported metal catalysts.This is particularly true for single-atom catalysts(SACs)and pseudo-single-atom catalysts(pseudo-SACs),where all metal atoms are dispersed on,and interact directly with the support.Consequently,the MSI of SACs and pseudo-SACs are theoretically more sensitive to modulation compared to that of traditional nanoparticle catalysts.In this work,we experimentally demonstrated this hypothesis by an observed size-dependent MSI modulation.We fabricated CoFe2O4 supported Pt pseudo-SACs and nanoparticle catalysts,followed by a straightforward water treatment process.It was found that the covalent strong metal-support interaction(CMSI)in pseudo-SACs can be weakened,leading to a significant activity improvement in methane combustion reaction.This finding aligns with our recent observation of CoFe2O4 supported Pt SACs.By contrast,the MSI in Pt nanoparticle catalyst was barely affected by the water treatment,giving rise to almost unchanged catalytic performance.This work highlights the critical role of metal size in determining the MSI modulation,offering a novel strategy for tuning the catalytic performance of SACs and pseudo-SACs by fine-tuning their MSIs. 展开更多
关键词 Strongmetal-support interaction Single-atom catalyst Pseudo-single-atom catalyst Size dependence Pt/CoFe2O4catalyst
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P改性Pt/CeO2单原子催化剂的CO低温氧化催化性能研究 认领 引用 被引量：1
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作者 翟晓珊 王骞 +3 位作者 王梓林 吕岩 郭延文 丁传敏 《低碳化学与化工》 CAS 北大核心 2026年第4期31-37,共7页
CO是一种分布广泛的空气污染物,对环境和人体健康构成重大威胁。目前,CO热催化氧化被认为是最节能、最高效的转化方法,而采用传统浸渍法制备的Pt/CeO2催化剂已接近其催化性能的极限。对于负载型Pt/CeO2单原子催化剂而言,载体的表... CO是一种分布广泛的空气污染物,对环境和人体健康构成重大威胁。目前,CO热催化氧化被认为是最节能、最高效的转化方法,而采用传统浸渍法制备的Pt/CeO2催化剂已接近其催化性能的极限。对于负载型Pt/CeO2单原子催化剂而言,载体的表面性质以及金属单原子的局部配位环境对其催化性能有重要影响。通过浸渍法引入磷酸制备了P改性单原子催化剂Pt/CeO2-yPOx,利用XRD、CO-DRIFTS和FT-IR等方法对催化剂的结构进行了表征,并对其催化性能进行了研究。结果表明,当m(磷酸)/m(CeO2)≤0.0850时,Pt以单原子的形式存在于催化剂中。Pt/CeO2-yPOx中,形成了P—O—Pt配位,并且其Lewis酸量增大,也产生了微量的Brønsted酸,有利于CO吸附。同时,Pt/CeO2-yPOx的还原性能提高,所以其CO低温氧化催化性能明显提升。其中,Pt/CeO2-0.085POx催化性能最优,使得CO转化温度降低为40℃,CO转化率达到100%的温度降低为110℃。 展开更多
关键词 Pt/CeO2 CO低温氧化 P改性 单原子催化剂
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Identification of relevant active sites and a mechanism study for reverse water gas shift reaction over Pt/CeO_2 catalysts 认领 引用 被引量：10
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作者 Xiaodong Chen Xiong Su +5 位作者 Binglian Liang Xiaoli Yang Xinyi Ren Hongmin Duan Yanqiang Huang Tao Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2016年第6期1051-1057,共7页
Reverse water gas shift (RWGS) reaction can serve as a pivotal stage in the CO2 conversion processes, which is vital for the utilization of CO2. In this study, RWGS reaction was performed over Pt/CeO2 catalysts at the... Reverse water gas shift (RWGS) reaction can serve as a pivotal stage in the CO2 conversion processes, which is vital for the utilization of CO2. In this study, RWGS reaction was performed over Pt/CeO2 catalysts at the temperature range of 200-500 degrees C under ambient pressure. Compared with pure CeO2, Pt/CeO2 catalysts exhibited superior RWGS activity at lower reaction temperature. Meanwhile, the calculated TOF and E-a values are approximately the same over these Pt/CeO2 catalysts pretreated under various calcination conditions, indicating that the RWGS reaction is not affected by the morphologies of anchored Pt nanoparticles or the primary crystallinity of CeO2. TPR and XPS results indicated that the incorporation of Pt promoted the reducibility of CeO2 support and remarkably increased the content of Ce 3 + sites on the catalyst surface. Furthermore, the CO TPSR-MS signal under the condition of pure CO2 flow over Pt/CeO 2 catalyst is far lower than that under the condition of adsorbed CO2 with H-2 -assisted flow, revealing that CO2 molecules adsorbed on Ce3+ active sites have difficult in generating CO directly. Meanwhile, the adsorbed CO2 with the assistance of H-2 can form formate species easily over Ce3+ active sites and then decompose into Ce3+-CO species for CO production, which was identified by in-situ FTIR. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B. V. and Science Press. All rights reserved. 展开更多
关键词 RWGS reaction Pt/CeO2 catalyst Formate intermediate Mechanism
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Effect of CeO2-ZrO2 on Pt/C electrocatalysts for alcohols oxidation 认领 引用 被引量：7
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作者 王青春 刘振朋 +3 位作者 安胜利 王瑞芬 王艳玲 徐拓 《Journal of Rare Earths》 SCIE EI CAS CSCD 2016年第3期276-282,共7页
The electrocatalytic activity and stability of Pt/C catalyst modified by using CeO_2-ZrO_2 mixed oxides for the alcohols electrochemical oxidation as probes were investigated. The catalyst samples were characterized b... The electrocatalytic activity and stability of Pt/C catalyst modified by using CeO_2-ZrO_2 mixed oxides for the alcohols electrochemical oxidation as probes were investigated. The catalyst samples were characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The electrochemical properties were measured by a three electrode system on electrochemical workstation（IVIUM）. The results showed that the presence of CeO_2-ZrO_2 might be associated with the presence of Pt, which indicated that possibly there was synergistic effect between CeO_2-ZrO_2 and Pt nanoparticles. The electrocatalytic activity and stability of Pt-MO_x/C（M=Ce, Zr） for methanol and ethanol oxidation was better than that of Pt-CeO_2/C, which was attributed to that CeO_2-ZrO_2 composited oxides enhanced oxygen mobility and promoted oxygen storage capacity（OSC）. Furthermore, the best performance was found when the molar ratio of CeO_2 to ZrO_2 was 2：1 for the oxidation of methanol and ethanol. The forward peak current density of Pt-MO_x/C（M=Ce, Zr, Ce：Zr=2：1） towards the methanol electrooxidation was about 3.8 times that of Pt-CeO_2/C. Pt-MO_x/C（M=Ce, Zr） appeared to be a promising and less expensive methanol oxidation anode catalyst. 展开更多
关键词 CeO2-ZrO2 composite oxide catalyst preparation characterization performance rare earths
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Boosting the water gas shift reaction on Pt/CeO2-based nanocatalysts by compositional modification: Support doping versus bimetallic alloying 认领 引用 被引量：6
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作者 Kun Yuan Xiao-Chen Sun +4 位作者 Hai-Jing Yin Liang Zhou Hai-Chao Liu Chun-Hua Yan Ya-Wen Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第4期241-249,共9页
The water gas shift reaction is of vital significance for the generation and transition of energy due to the application in hydrogen production and industries such as ammonia synthesis and fuel cells.The influence of ... The water gas shift reaction is of vital significance for the generation and transition of energy due to the application in hydrogen production and industries such as ammonia synthesis and fuel cells.The influence of support doping and bimetallic alloying on the catalytic performance of Pt/Ce O2-based nanocatalysts in water gas shift reaction was reported in this work.Various lanthanide ions and 3d transition metals were respectively introduced into the Ce O2support or Pt to form Pt/Ce O2:Ln(Ln=La,Nd,Gd,Tb,Yb)and Pt M/Ce O2(M=Fe,Co,Ni)nanocatalysts.The sample of Pt/Ce O2:Tb showed the highest activity(TOF at 200℃=0.051 s-1)among the Pt/Ce O2:Ln and the undoped Pt/Ce O2catalysts.Besides,the sample of Pt Fe/Ce O2exhibited the highest activity(TOF at 200℃=0.12 s-1)among Pt M/Ce O2catalysts.The results of the multiple characterizations indicated that the catalytic activity of Pt/Ce O2:Ln catalysts was closely correlated with the amount of oxygen vacancies in doped ceria support.However,the different activity of Pt M/Ce O2bimetallic catalysts was owing to the various Pt oxidation states of the bimetals dispersed on ceria.The study of the reaction pathway indicated that both the samples of Pt/Ce O2and Pt/Ce O2:Tb catalyzed the reaction through the formate pathway,and the enhanced activity of the latter derived from the increased concentration of oxygen vacancies along with promoted water dissociation.As for the sample of Pt Fe/Ce O2,its catalytic mechanism was the carboxyl route with a higher reaction rate due to the moderate valence of Pt along with improved CO activation. 展开更多
关键词 Pt/CeO2catalysts Water–gas shift reaction Support doping Bimetallic alloying
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Critical role of CoO modification on Pt/Al2O3for efficient H18-DBT dehydrogenation in LOHC systems 认领 引用
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作者 Ligang Zhang Rudong Liu +5 位作者 Chang Xu Chuanze Feng Sicong Qiu Nian Lei Kuo Liu Tao Zhang 《ENGINEERING Chemical Engineering》 SCIE EI CAS CSCD 2026年第6期37-47,共11页
Liquid organic hydrogen carriers(LOHCs)represent a highly promising strategy for hydrogen storage and long-distance transport,offering a safe and economically viable solution to key infrastructure challenges.The effec... Liquid organic hydrogen carriers(LOHCs)represent a highly promising strategy for hydrogen storage and long-distance transport,offering a safe and economically viable solution to key infrastructure challenges.The effective application of LOHCs requires dehydrogenation catalysts that strike an optimal balance between activity and stability.Herein,we report a precisely engineered CoOx-modified Pt/Al2O3catalytic system that exhibits outstanding performance in the dehydrogenation of perhydro-dibenzyltoluene(H18-DBT).Systematic investigations identify a critical CoOx loading threshold at 1 wt%,at which the catalyst achieves a maximum dehydrogenation degree(DoD)of 93%and a H2 production rate of 20.98×10³molH,molpt-1h-1 at 300°C for dehydrogenation,outperforming all the catalysts reported in the literature.However,increasing the Co loading from 1 to 10 wt%results in a sharp decline in DoD from 93%to 7.2%.With the increasing CoOx content,the cobalt species initially form amorphous CoO clusters,which subsequently transform into crystalline Co3O4.The amorphous CoO is found to be the key species responsible for enhanced dehydrogenation activity by increasing the electron density and reducing the particle size of Pt,thereby promoting dehydrogenation while suppressing the hydrogenation capability. 展开更多
关键词 LOHCs DBT CoO Pt based-bimetallic catalyst H2 storage
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Grain boundary engineering of CeO2 induced electron redistribution for dimethyl carbonate synthesis from CO2 认领 引用
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作者 Guoqiang Hou Di Xu +3 位作者 Haifeng Fan Yangyang Li Siyi Huang Mingyue Ding 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2026年第1期316-329,共14页
Direct synthesis of dimethyl carbonate(DMC)from CO2 is critical for achieving carbon neutrality,yet the sluggish formation and conversion of the key*CH₃OCOO intermediate-due to the difficulty of C-O coupling-limit ... Direct synthesis of dimethyl carbonate(DMC)from CO2 is critical for achieving carbon neutrality,yet the sluggish formation and conversion of the key*CH₃OCOO intermediate-due to the difficulty of C-O coupling-limit high DMC yields.Herein,we developed a boric acid-assisted recrystallization strategy to fabricate grain-boundary-rich CeO2 hollow nanospheres,which serve as an efficient catalyst for CO2 to DMC synthesis.The introduction of grain-boundary(GBs)induced the electron redistribution,which led a decrease in the electron density of bulk Ce ions and created a localized electron-rich region at homogeneous interface.This unique electronic landscape promoted reactive methoxy formation and stronger CO2 adsorption,thereby enabling more efficient coupling of*CH3O and*CO2 to form the*CH3OCOO.Concurrently,the enhanced CO2 adsorption facilitated the dissociation of*CH3OCOO and subsequent DMC formation.As a result,the 4%BCeO2-GBs achieved an advantageous DMC yield of 19.8 mmol/g.In the assistance of dehydrating agent,the catalyst delivered a remarkable 264.2 mmol/g DMC yield and 7.12%methanol conversion,which was 32 times higher than commercial CeO2.This study elucidated the intrinsic mechanisms governing*CH3OCOO intermediate behavior and offers valuable guidance for CO2 converting into high-value organic chemicals. 展开更多
关键词 Dimethyl carbonate synthesis CeO2 catalyst Grain boundary engineering Electron redistribution Reaction intermediates
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甲基环己烷(MCH)高效脱氢Pt/Al2O3催化剂载体性能优化及Pt的高分散机制 认领 引用 被引量：1
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作者 苏健利 李长旭 +6 位作者 陈春明 安会丽 于峰 陈树伟 潘大海 闫晓亮 李瑞丰 《化学学报》 SCIE CAS CSCD 北大核心 2026年第1期20-29,共10页
以经溶剂限域水解-聚合法所得介孔氧化铝(MA)为载体,借助焙烧条件的调控,优化MA的晶相、织构及表面性质,提高低负载量Pt(w=0.5%)在MA孔壁表面上的分散度,继而提升所得催化剂对甲基环己烷(MCH)脱氢反应的催化性能.结果表明,经450℃焙烧后... 以经溶剂限域水解-聚合法所得介孔氧化铝(MA)为载体,借助焙烧条件的调控,优化MA的晶相、织构及表面性质,提高低负载量Pt(w=0.5%)在MA孔壁表面上的分散度,继而提升所得催化剂对甲基环己烷(MCH)脱氢反应的催化性能.结果表明,经450℃焙烧后, MA载体具有γ-Al2O3晶相和较高的比表面积,且孔壁表面存在大量与Pt前体(氯铂酸)分子强静电键合作用的Ib型Al-OH,可促使Pt以超小纳米团簇形式高度均匀分散,致使所得催化剂展现出较现有Pt基催化剂更优异的MCH脱氢催化活性.例如,在300℃低温下,催化剂Pt/MA-450显示出高达2112 mmol·gPt-1·min-1的析氢速率,且在100 h反应过程或再生循环使用过程中仍能保持80%以上的初始催化活性. 展开更多
关键词 介孔材料 甲基环己烷(MCH)脱氢 Pt/Al2O3催化剂 载体-Pt前体界面作用 铝羟基
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Catalytic Oxidative Properties and Characterization of CuO/CeO_2 Catalysts 认领 引用 被引量：8
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作者 蒋晓原 周仁贤 +2 位作者 袁骏 吕光烈 郑小明 《Journal of Rare Earths》 SCIE EI CAS 2003年第1期55-59,共5页
The oxidative properties and characterization of CuO, CeO 2 and CuO/CeO 2 cata lysts were examined by means of a CO micro-reactor GC system, TPR, XPS and X-r ay diffraction Rietveld methods. The results show that eith... The oxidative properties and characterization of CuO, CeO 2 and CuO/CeO 2 cata lysts were examined by means of a CO micro-reactor GC system, TPR, XPS and X-r ay diffraction Rietveld methods. The results show that either CuO or CeO 2 ac tivity is quite low for CO oxidation. However, when CuO and CeO 2 are mixed, the oxidative activity of the catalyst increases significantly, probably owing to the valency status of copper species (Cu 2+ and Cu+) on the CeO 2 surfa ce, the dispersion and reducibility. XPS surface analysis shows that CuO loading is very important in forming of either Cu 2+ or Cu+. Rietveld analysis s hows that some CuO, which has smaller ion radius than Ce 4+, enters the Ce O 2 lattice after CuO and CeO 2 are mixed. When the CuO loading reaches 5.0%, the size of CuO crystals is a minimum (6.1 nm) and the micro-strain value i s a maximum (2.86×10 -3), resulting in high surface energy and the best ac tivity for CO oxidation. 展开更多
关键词 physical chemistry CuO/CeO 2 catalysts CO micro-reactor GC system rare earths
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Influence of preparation methods on the physicochemical properties and catalytic performance of MnO_x-CeO_2 catalysts for NH_3-SCR at low temperature 认领 引用 被引量：59
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作者 Xiaojiang Yao Kaili Ma +4 位作者 Weixin Zou Shenggui He Jibin An Fumo Yang Lin Dong 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第1期146-159,共14页
This work examines the influence of preparation methods on the physicochemical properties and catalytic performance of MnOx‐CeO2 catalysts for selective catalytic reduction of NO by NH3 (NH3‐SCR) at low temperature.... This work examines the influence of preparation methods on the physicochemical properties and catalytic performance of MnOx‐CeO2 catalysts for selective catalytic reduction of NO by NH3 (NH3‐SCR) at low temperature. Five different methods, namely, mechanical mixing, impregnation,hydrothermal treatment, co‐precipitation, and a sol‐gel technique, were used to synthesizeMnOx‐CeO2 catalysts. The catalysts were characterized in detail, and an NH3‐SCR model reaction waschosen to evaluate the catalytic performance. The results showed that the preparation methodsaffected the catalytic performance in the order: hydrothermal treatment > sol‐gel > co‐precipitation> impregnation > mechanical mixing. This order correlated with the surface Ce3+ and Mn4+ content,oxygen vacancies and surface adsorbed oxygen species concentration, and the amount of acidic sitesand acidic strength. This trend is related to redox interactions between MnOx and CeO2. The catalystformed by a hydrothermal treatment exhibited excellent physicochemical properties, optimal catalyticperformance, and good H2O resistance in NH3‐SCR reaction. This was attributed to incorporationof Mnn+ into the CeO2 lattice to form a uniform ceria‐based solid solution (containing Mn‐O‐Cestructures). Strengthening of the electronic interactions between MnOx and CeO2, driven by thehigh‐temperature and high‐pressure conditions during the hydrothermal treatment also improved the catalyst characteristics. Thus, the hydrothermal treatment method is an efficient and environment‐friendly route to synthesizing low‐temperature denitrification (deNOx) catalysts. 展开更多
关键词 MnOx‐CeO2 catalyst Preparation method Nitrogen oxides Low‐temperature NH3‐SCR Electron interaction Surface acidity
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Preparation, Characterization of CuO/CeO_2 and Cu/CeO_2 Catalysts and Their Applications in Low-Temperature CO Oxidation 认领 引用 被引量：9
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作者 郑修成 韩东战 +4 位作者 王淑萍 张守民 王淑荣 黄唯平 吴世华 《Journal of Rare Earths》 SCIE EI CAS 2005年第1期47-51,共5页
CeO2 was synthesized via sol-gel process and used as supporter to prepare CuO/CeO2, Cu/CeO2 catalysts by impregnation method. The catalytic properties and characterization of CeO2, CuO/CeO2 and Cu/CeO2 catalysts were ... CeO2 was synthesized via sol-gel process and used as supporter to prepare CuO/CeO2, Cu/CeO2 catalysts by impregnation method. The catalytic properties and characterization of CeO2, CuO/CeO2 and Cu/CeO2 catalysts were examined by means of a microreactor-GC system, HRTEM, XRD, TPR and XPS techniques. The results show that CuO has not catalytic activity and the activity of CeO2 is quite low for CO oxidation. However, the catalytic activity of CuO/CeO2 and Cu/ CeO2 catalysts increases significantly. Furthermore, the activity of CuO/CeO2 is higher than that of Cu/CeO2 catalysts. 展开更多
关键词 catalytic chemistry CuO/CeO2 catalysts Cu/CeO2 catalysts carbon monoxide oxidation rare earths
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Effects of WOx modification on the activity, adsorption and redox properties of CeO_2 catalyst for NO_x reduction with ammonia 认领 引用 被引量：26
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作者 Ziran Ma Duan Weng +1 位作者 Xiaodong Wu Zhichun Si 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第7期1305-1316,共12页
A series of WO3/CeO2 （WOx/CeO2） catalysts were synthesized by wet impregnation of ammonium metatungstate on a CeO2 support. The resulting solid acid catalysts were characterized by X-ray diffraction （XRD）, UV-Vis ... A series of WO3/CeO2 （WOx/CeO2） catalysts were synthesized by wet impregnation of ammonium metatungstate on a CeO2 support. The resulting solid acid catalysts were characterized by X-ray diffraction （XRD）, UV-Vis spectroscopy （UV-Vis）, Raman spectroscopy （Raman）, in-situ Fourier transform infrared spectroscopy （in-situ FT-IR） of ammonia adsorption, NH3-TPD, H2 temperature- programmed reduction （H2-TPR）, NH3/NO oxidation and activity measurements for NOx reduction by NH3 （NH3-SCR）. The results show that polytungstate （WOx） species are the main species of tungsten oxide on the surface of ceria. The addition of tungsten oxide enhances the BriSnsted acidity of ceria catalysts remarkably and decreases the amount of surface oxygen on celia, with strong interaction between CeO2 and WOx. As a result, the N2 selectivity of NH3 oxidation and NH3-SCR at high temperatures （〉 300℃） is enhanced. Therefore, a wide working temperature window in which NOx conversion exceeds 80% （NOx conversion 〉 80%） from 200 to 450℃, is achieved over 10 wt.% WOx/CeO2 catalyst. A tentative model of the NH3-SCR reaction route on WOx/CeO2 catalysts is presented. 展开更多
关键词 NOx reduction WOx/CeO2 catalyst redox NH3 adsorption
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Propene and CO oxidation on Pt/Ce-Zr-SO_42- diesel oxidation catalysts:Effect of sulfate on activity and stability 认领 引用 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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CeO_2-supported vanadium oxide catalysts for soot oxidation:the roles of molecular structure and nanometer effect 认领 引用 被引量：6
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作者 刘坚 赵震 +2 位作者 徐春明 段爱军 姜桂元 《Journal of Rare Earths》 SCIE EI CAS 2010年第2期198-204,共7页
The nanometer CeO2 powder was prepared by the method of microwave-assisted heating hydrolysis,and the nanometer CeO2-supported or ordinary CeO2-supported vanadia catalysts with different vanadium loadings(atomic ratio... The nanometer CeO2 powder was prepared by the method of microwave-assisted heating hydrolysis,and the nanometer CeO2-supported or ordinary CeO2-supported vanadia catalysts with different vanadium loadings(atomic ratios:100V/Ce=0.1,1,4,10,and 20) were prepared by an incipient-wetness impregnation method.Spectroscopic techniques(XRD,FT-IR,Raman and UV-Vis DRS) were utilized to characterize the structures of VOx/CeO2 catalysts.The results showed that the structures of CeO2-supported vanadium oxide catalysts de... 展开更多
关键词 vanadium oxide catalyst CeO2 nanometer soot combustion rare earths
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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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Electronic and geometric structure of the copper-ceria interface on Cu/CeO2 catalysts 认领 引用 被引量：8
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作者 Yan Zhou Aling Chen +1 位作者 Jing Ning Wenjie Shen 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第6期928-937,共10页
The atomic structure of the active sites in Cu/CeO2 catalysts is intimately associated with the copper-ceria interaction. Both the shape of ceria and the loading of copper affect the chemical bonding of copper species... The atomic structure of the active sites in Cu/CeO2 catalysts is intimately associated with the copper-ceria interaction. Both the shape of ceria and the loading of copper affect the chemical bonding of copper species on ceria surfaces and the electronic and geometric character of the relevant interfaces. Nanostructured ceria, including particles(polyhedra), rods, and cubes, provides anchoring sites for the copper species. The atomic arrangements and chemical properties of the(111),(110) and(100) facets, preferentially exposed depending on the shape of ceria, govern the copper-ceria interactions and in turn determine their catalytic properties. Also, the metal loading significantly influences the dispersion of copper species on ceria with a specific shape, forming copper layers, clusters, and nanoparticles. Lower copper contents result in copper monolayers and/or bilayers while higher copper loadings lead to multi-layered clusters and faceted particles. The active sites are usually generated via interactions between the copper atoms in the metal species and the oxygen vacancies on ceria, which is closely linked to the number and density of surface oxygen vacancies dominated by the shape of ceria. 展开更多
关键词 Cu/CeO2 catalyst Ceria shape Oxygen vacancy Copper particle Copper-ceria interface Active site
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Hydrogen production by steam reforming of ethanol over copper doped Ni/CeO_2 catalysts 认领 引用 被引量：6
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作者 刘其海 刘自力 +2 位作者 周新华 李翠金 丁娇 《Journal of Rare Earths》 SCIE EI CAS CSCD 2011年第9期872-877,共6页
High surface area CeO2 was prepared by the surfactant-assisted route and was employed as catalyst support. The 0-3 at.% Cu doped Cu-Ni/CeO2 catalysts with 10 wt.% and 15 wt.% of total metal loading were prepared by an... High surface area CeO2 was prepared by the surfactant-assisted route and was employed as catalyst support. The 0-3 at.% Cu doped Cu-Ni/CeO2 catalysts with 10 wt.% and 15 wt.% of total metal loading were prepared by an impregnation-coprecipitation method. The influence of Cu atomic content on the catalytic performance was investigated on the steam reforming of ethanol （SRE） for H2 production and the catalysts were characterized by N2 adsorption, inductively coupled plasma （ICP）, X-ray diffraction （XRD）, transmission electron microscopy （TEM）, temperature-programmed rerduction （TPR） and H2-pulse chemisorption techniques. The activity and products distribution behaviors of the catalysts were significantly affected by the doped Cu molar content based on the promotion effect on the dispersion of NiO particles and the interactions between Cu-Ni metal and CeO2 support. Significant increase in the ethanol conversion and hydrogen selectivity were obtained when moderate Cu metal was doped into the Ni/CeO2 catalyst. Over both of the 10Ni98.5Cu1.5/CeO2 and 15Ni98.5Cu1.5/CeO2 catalysts, more than 80% of ethanol conversion and 60% of H2 selectivity were obtained in the ethanol steam-reforming when the reaction temperature was above 450 ℃. 展开更多
关键词 copper dopant Cu-Ni/CeO2 catalyst ethanol steam reforming hydrogen production rare earths
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Evaluation of H2 Influence on the Evolution Mechanism of NOx Storage and Reduction over Pt–Ba–Ce/c-Al2O3 Catalysts 认领 引用 被引量：4
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作者 Pan Wang Jing Yi +2 位作者 Chuan Sun Peng Luo Lili Lei 《Engineering》 SCIE EI CAS 2019年第3期568-575,共8页
In this investigation, Pt–Ba–Ce/c-Al2O3 catalysts were prepared by incipient wetness impregnation and experiments were performed to evaluate the influence of H2 on the evolution mechanism of nitrogen oxides (NOx) st... In this investigation, Pt–Ba–Ce/c-Al2O3 catalysts were prepared by incipient wetness impregnation and experiments were performed to evaluate the influence of H2 on the evolution mechanism of nitrogen oxides (NOx) storage and reduction (NSR). The physical and chemical properties of the Pt–Ba–Ce/c- Al2O3 catalysts were studied using a combination of characterization techniques, which showed that PtOx, CeO2, and BaCO3, whose peaks were observed in X-ray diffraction (XRD) spectra, dispersed well on the c-Al2O3, as shown by transmission electron microscope (TEM), and that the difference between Ce3+ and Ce4+, as detected by X-ray photoelectron spectroscopy (XPS), facilitated the migration of active oxygen over the catalyst. In the process of a complete NSR experiment, the NOx storage capability was greatly enhanced in the temperature range of 250–350℃, and reached a maximum value of 315.3μmol·gcat^-1 at 350℃, which was ascribed to the increase in NO2 yield. In a lean and rich cycling experiment, the results showed that NOx storage efficiency and conversion were increased when the time of H2 exposure (i.e., 30, 45, and 60 s) was extended. The maximum NOx conversion of the catalyst reached 83.5% when the duration of the lean and rich phases was 240 and 60 s, respectively. The results revealed that increasing the content of H2 by an appropriate amount was favorable to the NSR mechanism due to increased decomposition of nitrate or nitrite, and the refreshing of trapping sites for the next cycle of NSR. 展开更多
关键词 Pt–Ba–Ce/c-Al2O3 catalysts Physicochemical properties NOx storage and reduction emission H2 reductant
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Effect of yttrium addition on water-gas shift reaction over CuO/CeO_2 catalysts 认领 引用 被引量：5
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作者 佘育生 李雷 +3 位作者 詹瑛瑛 林性贻 郑起 魏可镁 《Journal of Rare Earths》 SCIE EI CAS 2009年第3期412-418,共7页
This paper presented a study on the role of yttrium addition to CuO/CeO2 catalyst for water-gas shift reaction. A single-step co-precipitation method was used for preparation of a series of yttrium doped CuO/CeO2 cata... This paper presented a study on the role of yttrium addition to CuO/CeO2 catalyst for water-gas shift reaction. A single-step co-precipitation method was used for preparation of a series of yttrium doped CuO/CeO2 catalysts with yttrium content in the range of 0-5wt.%. Properties of the obtained samples were characterized and analyzed by X-ray diffraction （XRD）, Raman spectroscopy, H2-TPR, cyclic voltammetry （CV） and the BET method. The results revealed that catalytic activity was increased with the yttrium content at first, but then decreased with the further increase of yttrium content. Herein, CuO/CeO2 catalyst doped with 2wt.% of yttrium showed the highest catalytic activity （CO conversion reaches 93.4% at 250 ℃） and thermal stability for WGS reaction. The catalytic activity was correlated with the surface area, the area of peak γ of H2-TPR profile （i.e., the reduction of surface copper oxide （crystalline forms） interacted with surface oxygen vacancies on ceria）, and the area of peak C2 and A1 （Cu^0→←Cu^2＋ in cyclic voltammetry process）, respectively. Besides, Raman spectra provided evidences for a synergistic Cu-Ovacancy interaction, and it was indicated that doping yttrium may facilitate the formation of oxygen vacancies on ceria. 展开更多
关键词 CuO/CeO2 catalyst water-gas shift yttrium cyclic voltammetry rare earths
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