CN108620069A - Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂的制备方法及其应用 - Google Patents
Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂的制备方法及其应用 Download PDFInfo
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Abstract
本发明公开了一种化学催化剂的制备方法，特别是一种Ce改性介孔γ‑Al2O3负载Pd‑Pt纳米晶催化剂的制备方法，该方法中通过高温液相还原一步法得到Ce改性介孔γ‑Al2O3负载Pd‑Pt纳米晶催化剂。同时，本发明中还提供了一种Ce改性介孔γ‑Al2O3负载Pd‑Pt纳米晶催化剂的应用，在于上述Ce改性介孔γ‑Al2O3负载Pd‑Pt纳米晶催化剂可用于低浓度苯的催化燃烧。本发明制备的一种Ce改性介孔γ‑Al2O3负载Pd‑Pt纳米晶催化剂的反应活性较高；另外，其制备方法简单，可重复性强，贵金属纳米晶颗粒直径小。
Description
技术领域
本发明涉及一种化学催化剂的制备方法，特别是一种Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂的制备方法及其应用，主要用于低浓度苯的催化燃烧。
背景技术
传统浸渍法制备Pd-Pt/Ce/Al2O3催化剂的步骤：
(1)Ce改性γ-Al2O3催化材料的制备：将γ-Al2O3磨成40-60目均匀颗粒，采用等体积浸渍法制备Ce，采用的前躯体为Ce(NO3)3·6H2O。浸渍过夜(放置12h)、炒干，于马弗炉中500℃焙烧2h，待用。
(2)Ce/Al2O3负载Pd-Pt催化剂的制备：采用等体积浸渍法制备Pd-Pt(Pd/Pt的摩尔比为1:1)，采用的前躯体为H2PdCl4和H2PtCl4。浸渍过夜(放置12h)、加水烤干、加水合肼静置3h，于马弗炉中500℃焙烧2h。
其不足之处：
(1)当金属浸渍量大时，浸渍后金属在多孔材料孔道内外分布不均匀；
(2)传统浸渍法所制备的金属催化剂的催化活性相对较低，容易失活。
发明内容
本发明的目的是为了解决上述现有技术的不足，而提供一种Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂的制备方法。该方法中通过高温液相还原一步法得到Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂。
为了实现上述目的，本发明所设计的一种Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂的制备方法，其包括以下的步骤：
以质量为2.0g的10％Ce/Al2O3粉末计，取乙二醇100mL，两者加入三口烧瓶中，并用磁子搅拌0.5h；将总含量0.2％的Pd和Pt加入体系中，其中Pd/Pt的摩尔比为1:1，采用的前驱体为H2PdCl4和H2PtCl4溶液，通入高纯N2和冷凝水并继续搅拌12h，用NaOH溶液调节pH至11，在165℃搅拌3h，自然冷却至25℃，取出。用离心机洗净至无Cl离子和多余的乙二醇，在60℃烘箱中放置3h烘干，于马弗炉中500℃焙烧2h。
一种Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂的应用，在于上述Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂可用于低浓度苯的催化燃烧。
本发明与现有技术相比较，其具备以下的优点：
本发明所提供的一种利用高温液相还原一步法，合成的Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂(Pd-Pt/Ce/Al2O3)，其制备方法简单，可重复性强，金属纳米晶颗粒直径小，用于苯催化燃烧的剂反应活性高。合成的Pd-Pt/Ce/Al2O3为介孔材料，其比表面积达到178.2m2/g，总孔体积达到0.287cm3/g；0.2％Pd-Pt(1:1)/10％Ce/Al2O3的起燃温度为150℃，在200℃左右就能完全转化苯，且检测副产物只有H2O和CO2，并且在连续反应1000h后，催化活性没有降低，具有良好的稳定性。
附图说明
图1是Pd-Pt(1:1)/Al2O3及Pd-Pt(1:1)/10％Ce/Al2O3催化燃烧低浓度苯的催化活性图；
图2是催化材料的XRD图谱：(a)Pd/Al2O3；(b)Pt/Al2O3；(c)Pd-Pt/Al2O3；(d)Pd-Pt(1:1)/10％Ce/Al2O3；
图3是γ-Al2O3、Pd-Pt/Al2O3和Pd-Pt(1:1)/10％Ce/Al2O3的吸脱附等温线示意图；
图4是Pd-Pt(1:1)/Al2O3和Pd-Pt(1:1)/10％Ce/Al2O3的高分辨电镜图；
图5是苯-TPD的谱图：(a)吸附；(b)脱附；
图6是Ce(3d)的XPS谱图：(a)Pd-Pt/Ce/Al2O3-IM；(b)Pd-Pt/Ce/Al2O3；(c)Pd-Pt/Ce/Al2O3-used。
具体实施方式
下面结合附图和实施例对本发明进一步说明。
本实施例提供的一种Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂的制备方法，其包括以下的步骤：
1)γ-Al2O3载体的制备
在烧杯中用80mL去离子水水解6.0g AlCl3·6H2O和6.0g PEG，PEG/Al3+的摩尔比为0.05。水解30min后，向得到的水解混合物中滴加稀释的氨(25wt％)溶液。通过加入氨保持混合溶胶溶液的pH值为9.0。然后将上述溶液置于恒温水浴中，并在60℃下连续处理12h，冷却至25℃后，将白色胶体溶液过滤，用乙醇和去离子水洗涤数次，直到没有Cl-1及PEG分子被留下，随后将其在100℃下干燥10h，获得勃姆石溶胶。将所得的勃姆石溶胶在550℃下煅烧6h，制备载体γ-Al2O3，记为Al2O3。
2)10％Ce/Al2O3的制备
利用γ-Al2O3为载体，将γ-Al2O3磨成40-60目均匀颗粒，采用等体积浸渍法负载10％Ce，加入上述含量的硝酸铈，浸渍过夜(持续浸渍12h)、炒干、于马弗炉中500℃焙烧2h，Ce/Al2O3催化剂制备完成。
3)0.2％Pd-Pt/10％Ce/Al2O3纳米晶催化剂制备
利用液相高温还原一步法，以2.0g Ce/Al2O3粉末计，乙二醇(作为溶剂和还原剂)的用量为100mL加入三口烧瓶中，搅拌0.5h后，将负载总含量0.2％的Pd和Pt加入体系中(Pd/Pt的摩尔比为1:1)，所采用的前驱体为H2PdCl4和H2PtCl4，在高纯氮气保护下继续搅拌过夜(持续浸渍12h)。使用NaOH溶液调节混合液pH至11后，在165℃下搅拌3h，取出三口烧瓶，冷却至25℃，用离心机洗净至无Cl-(用硝酸银溶液检验)和多余的乙二醇；在60℃烘箱中放置3h烘干，马弗炉500℃(升温速率：10℃/min，由25℃开始升温)下焙烧2h，得到Pd-Pt/Ce/Al2O3纳米晶催化剂。
对上述实例所制得的0.2％Pd-Pt(1:1)/10％Ce/Al2O3催化剂进行催化燃烧低浓度苯的应用实验，其过程和结果如下所述：
催化剂活性评价在(WFS-3010，天津先权)催化剂活性评价装置，空速为20000h-1，通过GC1690型气相色谱(FID)检测反应器进出口中VOCs(苯的浓度为1000ppm)的浓度，检测条件为汽化室温度120℃，柱温120℃，并在N2000色谱工作站中记录和分析数据。见图1。
催化剂评价结果：
图1是Pd-Pt(1:1)/Al2O3和Pd-Pt(1:1)/10％Ce/Al2O3催化燃烧低浓度苯的催化活性图。从图中可以看出Pd-Pt(1:1)/Al2O3催化剂的起燃温度(转化率>20％)为140℃，完全转化温度为230℃。添加一定量的Ce后，催化活性有所提高。Pd-Pt(1:1)/10％Ce/Al2O3的起燃温度为120℃，在200℃左右就能完全转化苯，且检测副产物只有H2O和CO2。并且在连续反应1000h后，催化活性没有降低，具有良好的耐久性。
X射线衍射测定结果：
检测条件：在X射线粉末衍射仪(PANalytical)上进行，Cu Kα射线(300mA，40KV)，扫描速率为0.02°/s。层间距通过Bragg equation计算：2d001sinθ＝nλ，λ＝0.154nm。见图2。
从图2中可以看出，在Pd-Pt(1:1)/10％Ce/Al2O3催化剂中出现了CeO2的特征衍射峰，但是未出现PdO或PtO2的特征衍射峰，这是由于负载量太小或者高度分散而出现的结果。Pd-Pt(1:1)/10％Ce/Al2O3上Al2O3的峰相比于其他催化剂的Al2O3的峰强度有所减小，这是由于添加Ce后打乱了Al2O3的晶格排列。
比表面积和孔体积测定结果：
检测条件：催化剂的比表面积及孔结构在TristarⅡ3020(MicromeriticsCompany，USA)全自动吸附仪上测定。采用液氮温度(-195.8℃)下的N2吸附法测得比表面积(SBET)和平均孔径(d)，样品均于250℃抽真空预处理4h。采用Barrett-Joyner-Halenda(BJH)方法测定孔体积(Vp)。见图3。
从图3中，我们可以看出，所有材料的N2吸脱附等温线均为IV型，吸附-脱附回环属于H3型，出现在相对压力P/P0在0.45以上，表明催化材料均具有介孔结构。从表1中可知γ-Al2O3载体的SBET高达270.9m2/g，Vp达到为0.355cm3/g。与γ-Al2O3载体相比，负载Pd-Pt或Pd-Pt/Ce的催化剂表现出较低的SBET、Vp和d，这是由于部分金属氧化物(CeO2、PdO、PtO2)进入了Al2O3的孔道中，堵塞了一些孔，导致催化剂结构发生变化。
表1样品的比表面积，总孔体积和平均孔径
aBET specific surface area.
b Totalpore volume estimatedatP/P0＝0.99.
cMean diameter ofthepores,derived fromthe ratio ofthetotalporevolumeto the surface area.
高分辨电镜图结果：
检测条件：高分辨电镜(HR-TEM)利用JEM-21000F型透射电镜获得材料的表面形貌，工作电压为200kV。样品用环氧树脂包埋后切片，再进行测定。将样品粉末分散于无水乙醇，置超声波下振荡5min，用镀有碳膜的铜网捞取悬浮样品，待干燥后装入电镜预处理室，抽空后转入测量室，观察形貌，摄取照片。见图4。
图4是Pd-Pt(1:1)/Al2O3和Pd-Pt(1:1)/10％Ce/Al2O3的高分辨电镜图。从图4a和a’所示，PdO和PtO2颗粒均匀的分散在γ-Al2O3载体表面上，且颗粒直径大约在2-3nm。从图4b和b’可以看出，经过负载Ce后，活性组分的颗粒更均匀的分散在载体表面上，未出现明显的团聚现象，且其颗粒直径约在1-2nm，与XRD结果一致。在Pd-Pt(1:1)/10％Ce/Al2O3催化剂中，可以清楚地观察到在载体上的PdO或PtO2纳米颗粒的晶格条纹，其晶格条纹主要为(220)面，晶面间距为0.140nm，同时还存在着(200)面，晶面间距为0.198nm。
苯-TPD测定结果：
检测条件：在测量之前，将300mg催化剂在空气中于300℃预处理30min。在冷却至50℃后，将1000ppm苯注入反应体系中。达到吸附-解吸平衡后，除去苯，并将催化剂在1000ppm苯(20％O2/Ar，60mL/min)中以7.5℃/min步骤从50℃加热至500℃)。MS(QGA，Hiden，UK)在线测量苯的浓度以及任何可能的副产物和最终产物(COx和H2O)的存在。见图5。
从图5a中可以看出，催化剂对于苯吸附能力存在很大差异，如Pd-Pt(1:1)/10％Ce/Al2O3吸附苯的量最多，这是由于添加CeO2大大改善了苯对Pd-Pt纳米晶的吸附性能，因此吸附量变大。正如图5b所示，Pd-Pt(1:1)/Al2O3的苯脱附峰在110℃，Pd-Pt(1:1)/10％Ce/Al2O3的苯脱附峰在132℃左右，Pd-Pt(1:1)/10％Ce/Al2O3吸附的苯在较高温度下才能发生脱附，说明其吸附作用较强，吸脱附性能的提升改善了催化剂用于苯催化燃烧的性能。
X射线光电子衍射测定结果：
检测条件：XPS检测仪器为赛默飞公司生产的ESCALAB 250型仪器，样品在Al-Kα射线下进行检测，检测获得的数据需要进行碳校正来获得更加精确的结果。见图6。
一般而言，添加CeO2的催化剂中主要为Ce4+，但是在催化剂合成过程中，由于晶格扩张等过程，不可避免会产生一定量的Ce3+，而为了保证电荷平衡，Ce3+的存在必然导致一定量的氧空位的形成，从而进行电荷补偿，因此Ce4+/Ce3+的相互作用及转化过程增强了催化剂的氧储放和释放能力，从而有利于反应活性的提高。如图6所示，u’和v’是Ce3+的两个特征衍射峰，其他六个峰都为Ce4+的特征衍射峰。a中Ce4+/Ce3+＝4.91，b中Ce4+/Ce3+＝4.56，说明本发明制备的Pd-Pt/Ce/Al2O3催化剂中的Ce3+比传统的浸渍法多，c中Ce4+/Ce3+＝3.23，说明使用过的催化剂发生了氧化还原反应，Ce3+最多，具有最多的氧空位，且反应活性最高，与催化剂的活性评价相符。
Claims (2)
1.一种Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂的制备方法，其特征是包括以下的步骤：
Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂的制备：
以质量为2.0g的10％Ce/Al2O3粉末计，取乙二醇100mL，两者加入三口烧瓶中，搅拌0.5h；将负载总含量0.2％的Pd和Pt加入体系中，其中Pd/Pt的摩尔比为1:1，采用的前驱体为H2PdCl4和H2PtCl4，通入高纯N2和冷凝水并继续搅拌12h，用NaOH溶液调节pH至11，在165℃搅拌3h，自然冷却，取出，离心至无Cl离子和多余的乙二醇，在60℃烘箱中放置3h烘干，于马弗炉中500℃焙烧2h。
2.一种如权利要求1所述Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂的应用，其特征在于：Ce改性介孔γ-Al2O3负载Pd-Pt纳米晶催化剂可用于低浓度苯的催化燃烧。
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109772431A (zh) * | 2019-01-30 | 2019-05-21 | 绍兴文理学院 | Y改性MCM-22负载Pd纳米晶催化剂的制备方法及应用 |
| CN113210010A (zh) * | 2021-05-24 | 2021-08-06 | 无锡威孚环保催化剂有限公司 | 一种分区域涂覆的voc催化剂及其制备方法 |
| CN114405504A (zh) * | 2022-01-24 | 2022-04-29 | 中国科学院生态环境研究中心 | 一种低负载量的贵金属催化剂及其制备方法与应用 |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101559377A (zh) * | 2009-05-21 | 2009-10-21 | 浙江师范大学 | 一种消除甲醛的负载型催化剂及其制备方法和用途 |
| CN105268452A (zh) * | 2015-11-12 | 2016-01-27 | 西安石油大学 | 介孔负载型铜锰复合氧化物催化剂、制备及催化方法 |
-
2018
- 2018-05-21 CN CN201810485351.4A patent/CN108620069A/zh active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101559377A (zh) * | 2009-05-21 | 2009-10-21 | 浙江师范大学 | 一种消除甲醛的负载型催化剂及其制备方法和用途 |
| CN105268452A (zh) * | 2015-11-12 | 2016-01-27 | 西安石油大学 | 介孔负载型铜锰复合氧化物催化剂、制备及催化方法 |
Non-Patent Citations (2)
| Title |
|---|
| M. CHEN ET AL.,: "Synthesis of Pd/C Catalyst by Modified Polyol Process for Formic Acid Electrooxidation", 《FUEL CELLS》 * |
| TATIANA YUZHAKOVA ET AL.,: "PtPd-CeO2/γ-Al2O3 CATALYSTS FOR VOC TREATMENT OF EXHAUST GASES", 《ENVIRONMENTAL ENGINEERING AND MANAGEMENT JOURNAL》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109772431A (zh) * | 2019-01-30 | 2019-05-21 | 绍兴文理学院 | Y改性MCM-22负载Pd纳米晶催化剂的制备方法及应用 |
| CN113210010A (zh) * | 2021-05-24 | 2021-08-06 | 无锡威孚环保催化剂有限公司 | 一种分区域涂覆的voc催化剂及其制备方法 |
| CN113210010B (zh) * | 2021-05-24 | 2023-09-19 | 无锡威孚环保催化剂有限公司 | 一种分区域涂覆的voc催化剂及其制备方法 |
| CN114405504A (zh) * | 2022-01-24 | 2022-04-29 | 中国科学院生态环境研究中心 | 一种低负载量的贵金属催化剂及其制备方法与应用 |
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