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荧光XAFS表征Pt/BaAl_2O_4-Al_2O_3催化剂中的微量铂物种 被引量:2
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作者 孟明 张忠和 +2 位作者 罗金勇 林培琰 伏义路 《无机化学学报》 SCIE CAS CSCD 北大核心 2006年第2期298-302,共5页
随着稀薄燃烧(1ean—burn)发动机的推广使用和环保法规的日趋严格.消除稀燃尾气中的氮氧化物(NOx)已刻不容缓。NOx储存还原技术被认为是最具应用前景的方法之一。目前,对Pt/BaAl2O4-Al2O,体系中NOx储存与还原机制的研究较多,... 随着稀薄燃烧(1ean—burn)发动机的推广使用和环保法规的日趋严格.消除稀燃尾气中的氮氧化物(NOx)已刻不容缓。NOx储存还原技术被认为是最具应用前景的方法之一。目前,对Pt/BaAl2O4-Al2O,体系中NOx储存与还原机制的研究较多,但对该体系中微量铂物种微观结构及其与性能的关系研究较少.这主要是由于Pt含量(0.1wt%~0.5wt%)太低,分散度较高,使表征方法受到很大限制。 展开更多
关键词 pt/baal2o4-al2o3催化剂 氮氧化物储存 XAFS
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NO_x储存催化剂Pt/BaAl_2O_4-A1_2O_3的XAFS研究 被引量:7
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作者 李新刚 孟明 +4 位作者 林培琰 黄志坚 伏义路 谢亚宁 胡天斗 《物理化学学报》 SCIE CAS CSCD 北大核心 2001年第12期1072-1076,共5页
采用共沉淀-浸渍法在不同载体焙烧温度下,制备了不同Al/Ba原子比的Pt/BaAl2O4-A12O3系列样品。用XRD,XANES,EXAFS,以及NSC(NO_x storage capacity)测定等手段对样品的... 采用共沉淀-浸渍法在不同载体焙烧温度下,制备了不同Al/Ba原子比的Pt/BaAl2O4-A12O3系列样品。用XRD,XANES,EXAFS,以及NSC(NO_x storage capacity)测定等手段对样品的微观结构和NO_x储存性能进行了详细的表征.样品中Ba物种是以BaAl2O4和BaCO3两种混合物相的形式存在,且伴随着载体焙烧温度和Ba含量的降低,BaAl2O4物相的分散度变高,NO_x储存活性也随之提高,这表明BaAl2O4相的分散度与样品的NO_x储存性能密切相关,小颗粒的BaAl2O4相是NO_x的主要储存活性中心.在样品中,Pt物种以金属原子簇形式存在.分散度很高,其Pt—Pt壳层配位数较标样Pt粉有显著下降,Pt—Pt键长变短,出现了纳米收缩现象.高分散的小颗粒金属Pt原于簇为捕获和氧化NO_x的主要活性中心. 展开更多
关键词 Nox pt/baal2o4-al2o3 铝酸钡 氧化铝 储存 XAFS 氮氧化物 铂催化剂 发动机 尾气治理 负载型催化剂
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NOx storage and reduction assisted by non-thermal plasma over Co/Pt/Ba/γ-Al2O3 catalyst using CH_(4) as reductant 被引量:1
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作者 Tao ZHU Xing ZHANG +2 位作者 Nengjing YI Haibing LIU Zhenguo LI 《Plasma Science and Technology》 SCIE EI CAS CSCD 2021年第2期76-84,共9页
NOx storage and reduction(NSR)technology has been regarded as one of the most promising strategies for the removal of nitric oxides(NOx)from lean-burn engines,and the potential of the plasma catalysis method for NOx r... NOx storage and reduction(NSR)technology has been regarded as one of the most promising strategies for the removal of nitric oxides(NOx)from lean-burn engines,and the potential of the plasma catalysis method for NOx reduction has been confirmed in the past few decades.This work reports the NSR of nitric oxide(NO)by combining non-thermal plasma(NTP)and Co/Pt/Ba/γ-Al2O3(Co/PBA)catalyst using methane as a reductant.The experimental results reveal that the NOx conversion of NSR assisted by NTP is notably enhanced compared to the catalytic efficiency obtained from NSR in the range of 150°C–350°C,and NOx conversion of the 8%Co/PBA catalyst reaches 96.8%at 350°C.Oxygen(O_(2))has a significant effect on the removal of NOx,and the NOx conversion increases firstly and then decreases when the O_(2)concentration ranges from 2%to 10%.Water vapor reduces the NOx storage capacity of Co/PBA catalysts on account of the competition for adsorption sites on the surface of Co/PBA catalysts.There is a negative correlation between sulfur dioxide(SO_(2))and NOx conversion in the NTP system,and the 8%Co/PBA catalyst exhibits higher NOx conversion compared to other catalysts,which shows that Co has a certain SO_(2)resistance. 展开更多
关键词 non-thermal plasma Nox storage and reduction Co/pt/Ba/γ-al2o3 catalyst Nox conversion influence parameter
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制备条件对Pt/SO_4^(2-)/ZrO_2-Al_2O_3异构化性能的影响 被引量:5
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作者 乐晓光 徐俊 +1 位作者 宋月芹 周晓龙 《化工进展》 EI CAS CSCD 北大核心 2015年第2期419-424,共6页
采用沉淀法制备了Pt/SO42-/Zr O2-Al2O3(Pt SZA)催化剂,考察了氢氧化锆水凝胶干燥速率、锆盐浓度、铂含量、Al2O3和SO42-添加顺序等制备条件对Pt SZA异构化性能,尤其是低温异构化性能的影响,并用XRD和TG对催化剂进行了表征。结果表明,... 采用沉淀法制备了Pt/SO42-/Zr O2-Al2O3(Pt SZA)催化剂,考察了氢氧化锆水凝胶干燥速率、锆盐浓度、铂含量、Al2O3和SO42-添加顺序等制备条件对Pt SZA异构化性能,尤其是低温异构化性能的影响,并用XRD和TG对催化剂进行了表征。结果表明,提高水凝胶的干燥速率降低了Pt SZA催化剂中的硫含量,大大提高了催化剂中的单斜相,进而导致了催化剂低温失活加速以及高温活性下降。较低或较高的锆盐浓度劣化了Pt SZA的低温异构化稳定性,以0.4~0.6mol/L硝酸氧锆制备的催化剂硫含量和四方相氧化锆含量较高,异构化活性相对较好,Al2O3和SO42-添加顺序对Pt SZA异构化性能没有明显影响。 展开更多
关键词 制备 干燥 pt/So4^2-/Zro2-al2o3 烷烃 加氢异构
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Preparation of Pt/γ-Al2O3-C Heterogeneous Catalyst for Highly Selective Hydrogenation of Cinnamaldehyde Towards Cinnamyl Alcohol 被引量:2
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作者 MA Jun 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2017年第4期660-665,共6页
A Pt/γ-Al2O3-C heterogeneous catalyst with improved catalytic performance was successfully prepared. Bayberry talmin(BT), an abundant natural plant polyphenol, was utilized to modifiy the surface of the Pt/γ-Al2O3... A Pt/γ-Al2O3-C heterogeneous catalyst with improved catalytic performance was successfully prepared. Bayberry talmin(BT), an abundant natural plant polyphenol, was utilized to modifiy the surface of the Pt/γ-Al2O3 matrix and then stabilize Pt nanoparticles(NPs). The catalyst was systematically and specifically characterized by a collec- tion of analytic tools including XRD, XPS, FTIR, TEM, and TG. It was found that the Pt NPs were envenly dispered on the γ-Al2O3-C matrix. Meanwhile, when the catalyst was applied for selective hydrogenation of cilmamalde- hyde(CMA) in the presence of KOH promoter in solvent, excellent catalytic performance was obtained. The selecti- vity to cinnamyl alcohol(CMO) reached 97.88% with 88.45% CMA conversion within 30 min in the presence of 0.037 mol/L KOH, without significant loss of catalytic activity even under cyclic measurements for 5 times. The excelleut catalytic performances should be ascribed predominantly to the uniform and stable dispersion ofPt NPs on the γ-Al2O3-C matrix and the excellent heat stability of BT. 展开更多
关键词 Heterogeneous catalyst pt/γ-al2o3-C Barberry tannin Selective hydrogenation Ciunamaldehyde
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