Name: fabrication and testing of catalytic aerogels prepared via rapid supercritical extraction
Uploaded: 2018-08-31T12:30:00
Description: Watch this Scientific Journal Video about Fabrication and Testing of Catalytic Aerogels Prepared Via Rapid Supercritical Extraction at JoVE.com

催化气凝胶合成方法的发展由国家科学基金会 (NSF) 资助。DMR-1206631。UCAT 的设计和建造是通过 NSF 资助号提供的。CBET-1228851。另外的经费由联合学院教职员研究基金提供。作者还想确认托宾、奥得河 Bechu、瑞安 Bouck、亚当法院和 Vinicius 席尔瓦的贡献。

安全考虑: 在使用化学溶液和处理湿凝胶或催化气凝胶材料时, 随时佩戴安全眼镜或护目镜和实验室手套。处理丙烯氧化物, 四甲基硅酸 (TMOS), 乙醇, 甲醇, 氨, 纳米粒子和溶液中含有任何这些在通风罩内。在与它们合作之前, 请阅读所有化学品 (包括纳米粒子) 的安全数据表 (SDS)。在粉碎气凝胶样品和测试单元的装卸过程中, 佩戴微粒面罩。在操作液压热压机或催化试验台时佩戴安全眼镜或护目镜。?...

<ol>
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K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+vanadia-containing+aerogels+by+rapid+supercritical+extraction+for+applications+in+catalysis.">Preparation of vanadia-containing aerogels by rapid supercritical extraction for applications in catalysis.</a> J. Sol-Gel Sci. Technol. 77, 160-171 (2016).</li><li>Bouck, R. M., Anderson, A. M., Prasad, C., Hagerman, M. E., Carroll, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cobalt-alumina+Sol+Gels:+Effects+of+Heat+Treatment+on+Structure+and+Catalytic+Ability.">Cobalt-alumina Sol Gels: Effects of Heat Treatment on Structure and Catalytic Ability.</a> J. Non-Cryst. Solids. 453, 94-102 (2016).</li><li>Anderson, A. M., Donlon, E. A., Forti, A. A., Silva, V., Bruno, B. A., Carroll, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+Characterization+of+Copper-Nanoparticle-Containing+Silica+Aerogel+Prepared+Via+Rapid+Supercritical+Extraction+for+Applications+in+Three-Way+Catalysis.">Synthesis and Characterization of Copper-Nanoparticle-Containing Silica Aerogel Prepared Via Rapid Supercritical Extraction for Applications in Three-Way Catalysis.</a> MRS Advances. , 1-6 (2017).</li><li>Tobin, Z. M., Posada, L. F., Bechu, A. M., Carroll, M. K., Bouck, R. M., Anderson, A. M., Bruno, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+Characterization+of+Copper-containing+Alumina+and+Silica+Aerogels+for+Catalytic+Applications.">Preparation and Characterization of Copper-containing Alumina and Silica Aerogels for Catalytic Applications.</a> J. Sol-Gel Sci. Technol. , (2017).</li><li>Heck, R., Farrauto, R., Gulati, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Catalytic Air Pollution Technology. , (2009).</li><li>Gauthier, B. M., Bakrania, S. D., Anderson, A. M., Carroll, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Fast+Supercritical+Extraction+Technique+for+Aerogel+Fabrication.">A Fast Supercritical Extraction Technique for Aerogel Fabrication.</a> J. Non-Cryst. Solids. 350, 238-243 (2004).</li><li>Gauthier, B. M., Anderson, A. M., Bakrania, S. D., Mahony, M. K., Bucinell, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Method+and+Device+for+Fabricating+Aerogels+and+Aerogel+Monoliths+Obtained+Thereby.">Method and Device for Fabricating Aerogels and Aerogel Monoliths Obtained Thereby.</a> US Patent No. , (2008).</li><li>Gauthier, B. M., Anderson, A. M., Bakrania, S. D., Mahony, M. K., Bucinell, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Method+and+Device+for+Fabricating+Aerogels+and+Aerogel+Monoliths+Obtained+Thereby.">Method and Device for Fabricating Aerogels and Aerogel Monoliths Obtained Thereby.</a> US Patent. , (2011).</li><li>Roth, T. B., Anderson, A. M., Carroll, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+a+Rapid+Supercritical+Extraction+Aerogel+Fabrication+Process:+Prediction+of+Thermodynamic+Conditions+During+Processing.">Analysis of a Rapid Supercritical Extraction Aerogel Fabrication Process: Prediction of Thermodynamic Conditions During Processing.</a> J. Non-Cryst. Solids. 354 (31), 3685-3693 (2008).</li><li>Carroll, M. K., Anderson, A. M., Gorka, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparing+Silica+Aerogel+Monoliths+via+a+Rapid+Supercritical+Extraction+Method.">Preparing Silica Aerogel Monoliths via a Rapid Supercritical Extraction Method.</a> J. Vis. Exp. (84), e51421 (2014).</li><li>Harper-Leatherman, A. S., Pacer, E. R., Kosciuszek, N. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Encapsulating+Cytochrome+c+in+Silica+Aerogel+Nanoarchitectures+without+Metal+Nanoparticles+while+Retaining+Gas-phase+Bioactivity.">Encapsulating Cytochrome c in Silica Aerogel Nanoarchitectures without Metal Nanoparticles while Retaining Gas-phase Bioactivity.</a> J. Vis. Exp. (109), e53802 (2016).</li><li>Subrahmanyam, R., Gurikov, P., Meissner, I., Smirnova, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+Biopolymer+Aerogels+Using+Green+Solvents.">Preparation of Biopolymer Aerogels Using Green Solvents.</a> J. Vis. Exp. (113), e54116 (2016).</li><li>Campbell, P. G., Worsley, M. A., Hiszpanski, A. M., Baumann, T. F., Biener, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+Functionalization+of+3D+Nano-graphene+Materials:+Graphene+Aerogels+and+Graphene+Macro+Assemblies.">Synthesis and Functionalization of 3D Nano-graphene Materials: Graphene Aerogels and Graphene Macro Assemblies.</a> J. Vis. Exp. (105), e53235 (2015).</li><li>Kapteijn, F., Stegenga, S., Dekker, N. J. J., Bijsterbosch, J. W., Moulijn, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alternatives+to+noble+metal+catalysts+for+automotive+exhaust+purification.">Alternatives to noble metal catalysts for automotive exhaust purification.</a> Catalysis Today. 16 (2), 273-287 (1993).</li><li>Baumann, T., Gash, A., Chinn, S., Sawvel, A., Maxwell, R., Satcher, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+high-surface-area+alumina+aerogels+without+the+use+of+alkoxide+precursors.">Synthesis of high-surface-area alumina aerogels without the use of alkoxide precursors.</a> Chem. Mater. 17, 395-401 (2005).</li><li>Bruno, B. A., Anderson, A. M., Carroll, M. K., Brockmann, P., Swanton, T., Ramphal, I. A., Palace, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Benchtop+Scale+Testing+of+Aerogel+Catalysts.">Benchtop Scale Testing of Aerogel Catalysts.</a> SAE Technical Paper 2016-01-920. , (2016).</li><li>Anderson, A. M., Wattley, C. W., Carroll, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silica+Aerogels+Prepared+via+Rapid+Supercritical+Extraction:+Effect+of+Process+Variables+on+Aerogel+Properties.">Silica Aerogels Prepared via Rapid Supercritical Extraction: Effect of Process Variables on Aerogel Properties.</a> J. Non-Cryst. Solids. 355 (2), 101-108 (2009).</li></ol>

本文 RSCE 了催化气凝胶的制备方法和 UCAT 体系的应用。这些协议在其他方法上的主要优势是 RSCE 气凝胶的制造速度和相对便宜的 UCAT 催化试验方法。
要提取的凝胶可以通过多种方法制备, 包括将金属盐浸渍成氧化铝或硅胶湿胶基质, 将金属盐与铝盐作为共同前体, 并将含金属纳米粒子纳入硅胶气凝胶。当湿凝胶毛孔只含酒精和水 (即二氧化硅协议) 时, 不需要溶剂交换。在这种?...

硅和氧化铝基气凝胶具有密度低、孔隙率高、表面面积大、热稳定性好、导热系数低1的特点。这些属性使气凝胶材料具有吸引力的各种应用1,2。利用气凝胶的热稳定性和高表面积的一种应用是异质催化;几篇文章回顾文献在这个区域2,3,4,5。有许多方法来制造气凝胶基催化剂, 包括在硅或氧化铝气凝胶的框架内加入或诱捕催化物种5,6,7, 8,9,10,11。目前的工作重点是通过快速超临界萃取 (RSCE) 和气凝胶材料的催化试验制备汽车污染缓解的协议, 并以含铜气凝胶为例。
三路催化剂 (TWCs) 通常用于汽油机12的污染缓解设备。现代 TWCs 含有铂, 钯和/或铑, 铂族金属 (PGMs) 是罕见的, 因此, 昂贵和环境昂贵的获得。基于更容易获得的金属的催化剂材料将具有显著的经济和环境优势。
气凝胶可以通过湿凝胶制备, 采用多种方法1。目的是避免孔隙坍塌, 因为溶剂从凝胶中除去。本协议所使用的过程是一种快速超临界萃取 (RSCE) 方法, 其中萃取发生在一个金属模具内的凝胶在可编程液压热压机13,14,15, 16。以前在17号议定书中已经证明了使用这一 RSCE 工艺制备二氧化硅气凝胶石柱, 其中强调了与这种方法相关联的相对较短的准备时间。超临界 CO2萃取是一种更常见的方法, 但需要更多的时间, 需要更多的使用溶剂 (包括 CO2) 比 RSCE。其他团体最近发表了一系列协议, 用于制备各种类型的气凝胶, 利用超临界 CO2萃取18,19,20。
本文介绍了各种类型的含铜催化气凝胶的制备和催化试验规程。基于 Kapteijn等对汽车污染缓解有利的条件下碳基金属催化剂的无还原和 CO 氧化活性分级。21、铜被选作这项工作的催化金属。制造方法包括 (a) 铜盐浸渍 (IMP) 成氧化铝或硅胶湿凝胶11, (b) 使用铜 (II) 和铝盐作为共同前体 (co) 时, 制造铜氧化铝气凝胶6,22,(c) 在10制造过程中, 将含铜纳米粒子活捉成二氧化硅气凝胶基质。在每种情况下, RSCE 方法用于从湿凝胶基质13、14、15的毛孔中去除溶剂。
还介绍了利用联合催化试验台 (UCAT)23对这些材料作为汽车污染缓解 TWCs 的适用性的评估协议。UCAT 系统的目的, 其中的关键部分显示在图 1中, 是模拟在一个典型的汽油发动机催化转化器的化学, 热和流动条件。UCAT 函数通过模拟排气混合物在气凝胶样品上的控制温度和流速。气凝胶样品被装入一个2.25 厘米直径的管状填料床流动细胞 ("测试部分"), 其中包含样品在两个屏幕之间。将负载的流动单元放入烤箱中, 以控制废气和催化剂温度, 处理过的排气 (即排气流经填料床) 的样品, 以及未经治疗的气体 (即绕过填料床) 在温度范围内进行检查, 直至700 ˚C。三主要污染物 (CO、NO 和未燃碳氢化合物) 的浓度 (HCs) 是在气凝胶催化剂处理后使用五气体分析仪进行测量的, 并分别在未经治疗的 ("旁路") 流中进行测定;从这些数据中计算出每个污染物的"百分比换算" 。在这里描述的测试, 一个商业上可用的排气混合, 加利福尼亚汽车修理局 (酒吧) 97 低排放混合使用。UCAT 的设计和功能的完整细节在布鲁诺等23中提出。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57075/57075fig1.jpg"> 图1。UCAT 测试部分和取样系统。转载许可从 2016-01-0920 (布鲁诺等。23), 版权所有 2016 SAE 国际。未经 SAE 事先许可, 不允许进一步分发此种材料。<a href="//cloudflare.jove.com/files/ftp_upload/57075/57075fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>

<table border="0" cellpadding="0" cellspacing="0" width="670">
	<tbody>
		<tr height="76">
			<td height="76" style="height:76px;width:216px;">Variable micropipettor, 100-1000 &#181;L</td>
			<td style="width:168px;">Manufactured by Eppendorf, purchased from Fisher Scientific www.fishersci.com</td>
			<td style="width:119px;">S304665</td>
			<td style="width:167px;">Any 100-1000 &#181;L pipettor is suitable.</td>
		</tr>
		<tr height="76">
			<td height="76" style="height:76px;width:216px;">Variable Pipettor, 2.5-10 mL</td>
			<td style="width:168px;">Manufactured by Eppendorf, purchased from Fisher Scientific www.fishersci.com</td>
			<td style="width:119px;">21-379-25</td>
			<td style="width:167px;">Any variable pipettor is suitable.</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Pasteur pipettes</td>
			<td style="width:168px;">FisherScientific</td>
			<td style="width:119px;">13-678-6A</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="57">
			<td height="57" style="height:57px;width:216px;">Syringe</td>
			<td style="width:168px;">Purchased from Fisher Scientific</td>
			<td style="width:119px;">Z181390 syringe with Z261297 needle</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Digital balance</td>
			<td style="width:168px;">OHaus Explorer Pro</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">Any digital balance is suitable.</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Beakers</td>
			<td style="width:168px;">Purchased from Fisher Scientific</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">Any glass beaker is suitable.</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Graduated Cylinder</td>
			<td style="width:168px;">Purchased from Fisher Scientific</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">Any glass graduated cylinder is suitable.</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Magnetic Plate/Stirrer</td>
			<td style="width:168px;">FisherScientific Isotemp</td>
			<td style="width:119px;">SP88854200P</td>
			<td style="width:167px;">Any magnetic plate/stirrer is suitable.</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:216px;">Ultrasonic Cleaner</td>
			<td style="width:168px;">FisherScientific FS6</td>
			<td style="width:119px;">153356</td>
			<td style="width:167px;">Any sonicator is suitable.</td>
		</tr>
		<tr height="57">
			<td height="57" style="height:57px;width:216px;">Mold</td>
			<td style="width:168px;">Fabricated in House</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">Fabricate from cold-rolled steel or stainless steel.</td>
		</tr>
		<tr height="133">
			<td height="133" style="height:133px;width:216px;">Hydraulic Hot Press</td>
			<td style="width:168px;">Tetrahedron www.tetrahedronassociates.com</td>
			<td style="width:119px;">MTP-14</td>
			<td style="width:167px;">Any hot press with temperature and force control will work. Needs maximum temperature of ~550 F and maximum force of 24 tons.</td>
		</tr>
		<tr height="153">
			<td height="153" style="height:153px;width:216px;">UCAT (Union Catalytic Testbed)</td>
			<td style="width:168px;">Fabricated in House</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">Described in detail in reference #21:&#160; Bruno, B.A., Anderson, A.M., Carroll, M.K., Brockmann, P., Swanton, T., Ramphal, I.A., Palace, T. Benchtop Scale Testing of Aerogel Catalysts. SAE Technical Paper 2016-01-920 (2016).</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Bar 97 Gas</td>
			<td>Praxair</td>
			<td>MS_BAR97ZA-D7</td>
			<td></td>
		</tr>
	</tbody>
</table>

fabrication and testing of catalytic aerogels prepared via rapid supercritical extraction

介绍了将金属种类纳入二氧化硅和氧化铝气凝胶平台制备和测试催化气凝胶的规程。三制备方法: (a) 采用浸渍法将金属盐纳入二氧化硅或氧化铝湿凝胶中;(b) 采用共同前体方法将金属盐纳入氧化铝湿凝胶中;(c) 将金属纳米粒子直接添加到二氧化硅气凝胶前驱体混合物中。该方法利用液压热压机, 可快速 (< 6 小时) 超临界萃取, 结果为低密度气凝胶 (0.10 克/毫升) 和高表面积 (200-800 米2/克)。虽然这里的工作重点是使用铜盐和铜纳米粒子, 该方法可以实施使用其他金属盐和纳米粒子。文中还介绍了用于汽车污染缓解的气凝胶三路催化性能测试协议。这种技术使用定制的设备, 联合催化试验台 (UCAT), 其中模拟排气混合物通过气凝胶样品在控制温度和流速。该系统能够测量催化气凝胶在氧化和还原条件下的能力, 将 co、NO 和未燃烃 (HCs) 转化为较小的有害物种 (co2、H2O 和 N2)。举例说明了气凝胶的催化效果。

图 2显示了产生气凝胶的照相图像。由于湿凝胶在溶剂交换前被分解成块, 铝铜 imp 和硅铜 imp 气凝胶在小而不规则形状的单片中。从这些样品的着色清楚地看出, 气凝胶含有铜种类, 并且在材料中发生铜形态和/或配体结构的变化。铝铜 IMP 气凝胶 (图 2a) 呈红色, 呈绿色-灰色, 颜色为11。铝铜条子气凝胶 (未显示) ?...

Watch this Scientific Journal Video about Fabrication and Testing of Catalytic Aerogels Prepared Via Rapid Supercritical Extraction at JoVE.com

Fabrication and Testing of Catalytic Aerogels Prepared Via Rapid Supercritical Extraction

在这里, 我们提出了制备和测试催化气凝胶的协议, 将金属种类纳入二氧化硅和氧化铝气凝胶平台。介绍了用铜盐和含铜纳米微粒制备材料的方法。催化试验协议证明了这些气凝胶用于三路催化应用的有效性。

快速超临界萃取制备催化气凝胶的制备与试验研究

Protocols for preparing and testing catalytic aerogels by incorporating metal species into silica and alumina aerogel platforms are presented. Three ...

Research

JoVE Journal

Chemistry

In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions

In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions

在质谱选择离子软着陆准备好定义的表面原位二次离子质谱和红外光谱

Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of materials that are inaccessible using ...

科研

化学

Preparing Silica Aerogel Monoliths via a Rapid Supercritical Extraction Method

通过快速超临界萃取法制备二氧化硅气凝胶巨石

A procedure for the fabrication of monolithic silica aerogels in eight hours or less via a rapid supercritical extraction process is described. The ...

Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica

合成和金插在介孔二氧化硅的墙壁催化性能

As a promising catalytically active nano reactor, gold nanoparticles intercalated in mesoporous silica (GMS) were successfully synthesized and properties ...

Supercritical Nitrogen Processing for the Purification of Reactive Porous Materials

超临界氮处理的活性多孔材料的净化

Supercritical fluid extraction and drying methods are well established in numerous applications for the synthesis and processing of porous materials. ...

Preparation of Biopolymer Aerogels Using Green Solvents

生物聚合物气凝胶制备使用绿色溶剂

Although the first reports on aerogels made by Kistler1 in the 1930s dealt with aerogels from both inorganic oxides (silica and others) and biopolymers ...

Laboratory Production of Biofuels and Biochemicals from a Rapeseed Oil through Catalytic Cracking Conversion

通过催化裂化转换从菜籽油生物燃料和生物化学实验室生产

The work is based on a reported study which investigates the processability of canola oil (bio-feed) in the presence of bitumen-derived heavy gas oil ...

A Simple and Efficient Protocol for the Catalytic Insertion Polymerization of Functional Norbornenes

功能性降冰片烯的催化聚合插入一种简单高效的协议

Norbornene can be polymerized by a variety of mechanisms, including insertion polymerization whereby the double bond is polymerized and the bicyclic ...

Fabrication and Testing of Photonic Thermometers

光子温度计的制作与测试

In recent years, a push for developing novel silicon photonic devices for telecommunications has generated a vast knowledge base that is now being ...

Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area

Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area

化学沉淀法合成铌2O5改性高比表面积镍催化剂

We demonstrate a method for the synthesis of NixNb1-xO catalysts with sponge-like and fold-like nanostructures. By varying the Nb:Ni ratio, a series of ...

A Rapid Synthesis Method for Au, Pd, and Pt Aerogels Via Direct Solution-Based Reduction

直接溶液还原法快速合成金、钯、铂气凝胶的研究

Here, a method to synthesize gold, palladium, and platinum aerogels via a rapid, direct solution-based reduction is presented. The combination of various ...