CN103041816A - Self-protection nano-cobalt catalyst with high cyclic stability - Google Patents
Self-protection nano-cobalt catalyst with high cyclic stability Download PDFInfo
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- 239000003054 catalyst Substances 0.000 title claims abstract description 45
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- 239000002105 nanoparticle Substances 0.000 claims abstract description 45
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- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 39
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Abstract
本发明提供了一种高循环稳定性的自保护纳米钴催化剂,该纳米钴催化剂,在室温空气下,纳米金属钴Co催化硼胺AB水解产生氢气反应后,通过氧化刻蚀溶液中的Co纳米催化剂颗粒,使其转换为Co2+离子,Co2+离子能够在溶液中长时间保存,实现催化剂的自保护功能;然后再通过硼氢化钠NaBH4和AB将Co2+离子迅速的还原为Co纳米颗粒,实现Co催化剂的循环使用;再生的Co纳米催化剂颗粒拥有和初始Co纳米催化剂颗粒相同的高催化活性。该方法简单、有效、低成本,克服了催化AB制氢时非贵金属催化剂Co纳米粒子的氧化钝化,使其长时间循环稳定性,促进了车载移动氢源材料中储氢-放氢实际应用。
The invention provides a self-protecting nano-cobalt catalyst with high cycle stability. The nano-cobalt catalyst, after the nano-metal cobalt Co catalyzes the hydrolysis of boronamine AB to generate hydrogen under room temperature air, oxidizes the Co nanometer in the etching solution. Catalyst particles to convert them into Co 2+ ions, Co 2+ ions can be stored in the solution for a long time to realize the self-protection function of the catalyst; then quickly reduce Co 2+ ions to Co nanoparticles realize the recycling of Co catalysts; the regenerated Co nanocatalyst particles have the same high catalytic activity as the original Co nanocatalyst particles. The method is simple, effective, and low-cost, and overcomes the oxidation passivation of the non-precious metal catalyst Co nanoparticles when catalyzing AB hydrogen production, making it stable for long-term cycles, and promoting the practical application of hydrogen storage-dehydrogenation in vehicle-mounted mobile hydrogen source materials .
Description
技术领域 technical field
本发明涉及一种通过金属-金属离子可逆转变法制备高循环稳定性的自保护纳米钴催化剂。 The invention relates to a self-protected nano-cobalt catalyst with high cycle stability prepared by a metal-metal ion reversible transformation method. the
背景技术 Background technique
随着能源危机的产生和温室效应气体(二氧化碳、甲烷等)被大量排入到环境大气中,寻找一个可替代的清洁新能源变得非常重要。氢能作为一种丰富、可再生、无污染的能源便浮出水面来了。因此,在通向氢能源社会的过程中,寻找一种高效、安全的储氢材料便成为最困难的挑战。硼胺(NH3BH3,AB)由于高含氢量(19.6wt%)、高溶解性、无毒性和稳定性,可以作为一种非常有潜力的储氢材料。然而AB作为储氢材料被大量应用的一个最大障碍便是找到一种简单、高效、经济并且循环稳定性好的催化剂,来进一步改进在适当条件下其放氢动力学性能。 With the generation of the energy crisis and the large amount of greenhouse effect gases (carbon dioxide, methane, etc.) being discharged into the ambient atmosphere, it is very important to find an alternative clean new energy source. Hydrogen energy has surfaced as an abundant, renewable, and pollution-free energy source. Therefore, in the process of leading to a hydrogen energy society, finding an efficient and safe hydrogen storage material has become the most difficult challenge. Boronamine (NH 3 BH 3 , AB) can be used as a very promising hydrogen storage material due to its high hydrogen content (19.6 wt%), high solubility, non-toxicity and stability. However, one of the biggest obstacles to the extensive application of AB as a hydrogen storage material is to find a catalyst that is simple, efficient, economical, and has good cycle stability to further improve its hydrogen desorption kinetics under appropriate conditions.
相对于普通大块催化剂材料,纳米催化剂材料由于拥有大的表面体积比和高的催化活性,已经被大量的应用在很多重要的化学反应中。纳米催化剂材料的一个重要目标是使其拥有高的选择性、优良的催化活性、强的反应稳定性和低成本等性能。 Compared with ordinary bulk catalyst materials, nano catalyst materials have been widely used in many important chemical reactions due to their large surface-to-volume ratio and high catalytic activity. An important goal of nanocatalyst materials is to make them have high selectivity, excellent catalytic activity, strong reaction stability and low cost. the
在很多重要反应中,钴元素(Co)相对于贵金属元素的非贵金属,不仅在地壳中含量丰富,而且相对于贵金属元素来说,它具有较低成本,并且在很多重要反应中如:合成高碳(C3或者更高)醇反应、脱氢反应、氢气和氧气制备反应等,都具有很好的催化活性,因此作为催化材料受到了越来越多的关注。然而,Co纳米颗粒相对于贵金属颗粒而言在空气中更容易氧化,会导致催化剂颗粒的氧化钝化和较差的循环稳定性,尤其是当两次循环反应时间间隔比较长时,这就大大的限制了它的实际应用。近来,克服这个问题的主要方法是在Co纳米颗粒的表面加上一层稳定的包裹材料,比如硅、碳、过渡金属氧化物等;或者是在惰性气体下应用和储存纳米Co催化剂。可是这些方法存在着或多或少的缺点,比如稳定的外层包裹材料占据了Co催化剂的活性位,使其催化活性降低;惰性气体保护下,催化剂合成和应用的复杂性和高成本等。综上所述,寻找一种简单且有效的新方法用以避免Co纳米催化剂的长时间使用的活性降低的问题就显得非常有意义了。 In many important reactions, cobalt element (Co) is not only abundant in the earth's crust compared to the non-noble metals of noble metal elements, but also has a lower cost than noble metal elements, and in many important reactions such as: synthesis of high Carbon (C3 or higher) alcohol reactions, dehydrogenation reactions, hydrogen and oxygen production reactions, etc., all have good catalytic activity, so they have received more and more attention as catalytic materials. However, Co nanoparticles are more easily oxidized in air than noble metal particles, which will lead to oxidation passivation of catalyst particles and poor cycle stability, especially when the time interval between two cycle reactions is long, which greatly limits its practical application. Recently, the main method to overcome this problem is to add a layer of stable wrapping materials on the surface of Co nanoparticles, such as silicon, carbon, transition metal oxides, etc.; or to apply and store nano-Co catalysts under inert gas. However, these methods have more or less disadvantages, such as the stable outer coating material occupying the active site of the Co catalyst, reducing its catalytic activity; under the protection of inert gas, the complexity and high cost of catalyst synthesis and application, etc. To sum up, it is very meaningful to find a simple and effective new method to avoid the problem of Co nanocatalysts being degraded by long-term use. the
发明内容 Contents of the invention
本发明的目的在于提供一种该催化剂为通过金属(Co)-金属离子(Co2+)自由可逆转变法制备高循环稳定性的自保护纳米Co催化剂。所述的高循环稳定性的自保护纳米钴催化剂,在室温空气环境中,纳米金属Co催化AB水解产生氢气反应后,通过氧化刻蚀溶液中的Co纳米颗粒,使其转换为Co2+离子,而Co2+离子能够在溶液中长期保存,实现催化剂的自保护功能;然后再通过硼氢化钠(NaBH4)和AB将Co2+离子迅速的还原为Co纳米颗粒,实现催化剂的循环使用;而再生的Co纳米催化剂颗粒拥有和初始Co纳米催化剂颗粒相同的高催化活性。 The object of the present invention is to provide a self-protected nano-Co catalyst with high cycle stability prepared by the catalyst through the free and reversible transformation method of metal (Co)-metal ion (Co 2+ ). The self-protected nano-cobalt catalyst with high cycle stability, in the air environment at room temperature, after the nano-metallic Co catalyzes the hydrolysis of AB to generate hydrogen, the Co nanoparticles in the solution are oxidized and etched to convert them into Co 2+ ions , and Co 2+ ions can be stored in the solution for a long time to realize the self-protection function of the catalyst; then the Co 2+ ions can be quickly reduced to Co nanoparticles by sodium borohydride (NaBH 4 ) and AB to realize the recycling of the catalyst ; while the regenerated Co nanocatalyst particles have the same high catalytic activity as the original Co nanocatalyst particles.
本发明的技术方案是: Technical scheme of the present invention is:
一种高循环稳定性的自保护纳米钴催化剂,所述纳米钴催化剂通过以下方法制备: A self-protected nano-cobalt catalyst with high cycle stability, the nano-cobalt catalyst is prepared by the following method:
AB制氢过程所需化学药品的选择:硼胺AB,六水氯化钴CoCl2·6H2O,硼氢化钠NaBH4和氨水H5NO,纳米Co催化剂颗粒制备的具体步骤如下: The selection of chemicals required for the AB hydrogen production process: boronamine AB, cobalt chloride hexahydrate CoCl 2 6H 2 O, sodium borohydride NaBH 4 and ammonia water H 5 NO, the specific steps for the preparation of nano-Co catalyst particles are as follows:
步骤一,将0.01~0.05mmol的CoCl2·6H2O溶解于2~10mL的蒸馏水中,得到粉红色的CoCl2水溶液; Step 1, dissolving 0.01-0.05 mmol of CoCl 2 ·6H 2 O in 2-10 mL of distilled water to obtain a pink CoCl 2 aqueous solution;
步骤二,将30~70mg的AB和5~30mg的NaBH4溶解于2~10mL的蒸馏水中;
步骤三,将步骤二中的溶液加入到步骤一的溶液;
Step 3, the solution in
步骤四,在10-40℃下,将步骤三所得的溶液在空气中磁力搅拌均匀,可看到有黑色的悬浮颗粒产生,黑色悬浮颗粒即为Co纳米金属催化剂;
步骤五,通过气体量管测量步骤四中产生的氢气,水解制氢方程式为:
Step 5, measure the hydrogen produced in
AB+2H2O=NH4 ++BO2 -+3H2; AB+2H 2 O=NH 4 + +BO 2 - +3H 2 ;
步骤六,在10-40℃下,步骤四溶液产生氢气结束后,将黑色悬浮液在空气中磁力搅拌10-200min后,黑色悬浮液变成了粉红色液体,该粉红色的液体便是CoCl2溶液;
Step 6: At 10-40°C, after the solution in
步骤七,30~70mg的AB和5~30mg的NaBH4溶解于2~10mL的蒸馏水中; Step 7, 30-70 mg of AB and 5-30 mg of NaBH 4 are dissolved in 2-10 mL of distilled water;
步骤八,将步骤七溶液倒入步骤六溶液中,粉红色溶液再次变为黑色悬浮液;
步骤九,在10-40℃下,将步骤八所得的溶液在空气中磁力搅拌均匀,可看到有黑色的悬浮颗粒产生,黑色悬浮颗粒即为Co纳米金属催化剂;
Step 9, at 10-40°C, magnetically stir the solution obtained in
所用化学药品为硼胺90wt%的AB,六水氯化钴99wt%的CoCl2·6H2O,>96wt%的硼氢化钠NaBH4和25wt%~28wt%的氨水H5NO。 The chemicals used are AB with 90wt% boronamine, CoCl 2 ·6H 2 O with 99wt% cobalt chloride hexahydrate, >96wt% sodium borohydride NaBH 4 and 25wt%-28wt% ammonia water H 5 NO.
所述步骤一至四是将金属离子Co2+转变为纳米金属催化剂Co;步骤六是将纳米金属催化剂Co转变为金属离子Co2+,从而使纳米金属催化剂Co得到自我保护,实现催化剂的高循环稳定性;步骤九是将金属离子Co2+又转变为纳米金属催化剂Co;上述步骤一至九为一个反应循环,从而实现用金属-金属离子可逆转变法制备高循环稳定性的自保护纳米Co催化剂。 The steps 1 to 4 are to convert the metal ion Co 2+ into the nano-metal catalyst Co; step 6 is to convert the nano-metal catalyst Co into the metal ion Co 2+ , so that the nano-metal catalyst Co can be self-protected and realize the high circulation of the catalyst Stability; Step 9 is to convert metal ion Co 2+ into nano-metal catalyst Co; the above steps 1 to 9 are a reaction cycle, so as to realize the self-protected nano-Co catalyst with high cycle stability prepared by metal-metal ion reversible transformation method .
首次合成的Co纳米粒子尺寸为20nm并且团聚到一起像纳米链结构。 Co nanoparticles synthesized for the first time have a size of 20 nm and aggregate together like nanochain structures. the
再次合成的Co纳米金属颗粒为分散状态,其纳米颗粒大小为4nm左右。 The re-synthesized Co nano metal particles are in a dispersed state, and the size of the nanoparticles is about 4nm. the
本发明的技术效果是: Technical effect of the present invention is:
所用的简单但有效的金属-金属离子可逆转变法制备纳米Co催化剂,可以有效的避免非贵金属催化剂Co的氧化钝化,使其易于保存,实现自身的保护并且使纳米Co催化剂具有很高的循环稳定性。换句话说,我们可以将Co纳米颗粒完全转换为Co2+离子并长时间在空气中保存,然后轻松地将Co2+离子转换为与保存之前具有相似或相同的高催化活性的Co纳米颗粒,实现循环使用,从而使非贵金属纳米催化剂Co拥有很高的循环稳定性。此方法还节约了在催化剂选择、合成和应用中的成本。 The simple but effective metal-metal ion reversible transformation method used to prepare nano-Co catalysts can effectively avoid the oxidation passivation of non-noble metal catalysts Co, making it easy to store, achieving self-protection and making nano-Co catalysts have a high cycle stability. In other words, we can completely convert Co nanoparticles into Co ions and preserve them in air for a long time, and then easily convert Co ions into Co nanoparticles with similar or identical high catalytic activity as before preservation , to achieve recycling, so that the non-noble metal nanocatalyst Co has high cycle stability. This approach also saves costs in catalyst selection, synthesis and application.
附图说明 Description of drawings
图1金属(Co)-金属离子(Co2+)自由可逆转变示意图。 Fig. 1 Schematic diagram of free and reversible transformation of metal (Co)-metal ion (Co 2+ ).
图2紫外可见光谱图,其中:(a)是CoCl2溶液,(b)是Co纳米颗粒,(c)是空气中氧化刻蚀Co纳米颗粒后的溶液。 Fig. 2 UV-Vis spectrum diagram, wherein: (a) is CoCl 2 solution, (b) is Co nanoparticle, (c) is the solution after oxidative etching of Co nanoparticle in air.
图3Co纳米颗粒中元素的XPS图,其中: The XPS diagram of the elements in Figure 3Co nanoparticles, where:
图3(a)是Co的XPS图, Figure 3(a) is the XPS diagram of Co,
图3(b)是B的XPS图。 Figure 3(b) is the XPS diagram of B. the
图4不同催化剂催化AB制氢曲线,其中:(a)是初次产生的Co纳米颗粒,(b)是第5次循环再生的Co纳米颗粒,(c)是第10次循环再生的Co纳米颗粒。插入图:在纯水中储存7天后的Co纳米颗粒催化AB制氢曲线。 Figure 4. Hydrogen production curves of AB catalyzed by different catalysts, where: (a) is the Co nanoparticles produced for the first time, (b) is the Co nanoparticles regenerated in the fifth cycle, and (c) is the Co nanoparticles regenerated in the tenth cycle . Insert: AB hydrogen production curves catalyzed by Co nanoparticles after storage in pure water for 7 days. the
图5不同催化剂的TEM和SAED图,其中:(a)是初次合成的Co纳米粒子,(b)是第10次循环再生的Co纳米粒子。 Fig. 5 TEM and SAED images of different catalysts, where: (a) is the Co nanoparticles synthesized for the first time, and (b) is the Co nanoparticles regenerated in the 10th cycle. the
具体实施方式 Detailed ways
比较实施例1 Comparative Example 1
将0.03mmol的CoCl2·6H2O溶解于5mL的蒸馏水中,得到粉红色的CoCl2水溶液;50mg的AB和10mg的NaBH4溶解于5mL的蒸馏水,在25℃下,将该溶液加入到粉红色的CoCl2水溶液中磁力搅拌均匀,粉红色溶液迅速变为黑色悬浮液,如图3所示,X射线光电子能谱(XPS)结果显示,黑色悬浮颗粒即为Co纳米金属催化剂;在AB溶液制氢结束后,黑色悬浮Co纳米颗粒在氩气气氛下被搅拌200分钟。黑色悬浮液仍然没有变化,也就是说Co纳米颗粒在氩气中是稳定的。说明Co纳米颗粒在氩气氛围下,不能在该条件下实现纳米金属Co和Co2+相互转换,不能使纳米Co催化剂循环使用时实现自保护功能。 Dissolve 0.03 mmol of CoCl 2 6H 2 O in 5 mL of distilled water to obtain a pink CoCl 2 aqueous solution; 50 mg of AB and 10 mg of NaBH 4 are dissolved in 5 mL of distilled water, and add this solution to the pink color at 25 °C In the colored CoCl2 aqueous solution, the magnetic force stirs evenly, and the pink solution rapidly becomes a black suspension, as shown in Figure 3, X-ray photoelectron spectroscopy (XPS) results show that the black suspended particles are Co nanometer metal catalysts; in the AB solution After the hydrogen production was finished, the black suspended Co nanoparticles were stirred for 200 min under an argon atmosphere. The black suspension remained unchanged, which means that the Co nanoparticles were stable in argon. It shows that Co nanoparticles cannot realize the interconversion between nano-metal Co and Co 2+ under the condition of argon atmosphere, and cannot realize the self-protection function when the nano-Co catalyst is recycled.
比较实施例2 Comparative Example 2
将0.03mmol的CoCl2·6H2O溶解于5mL的蒸馏水中,得到粉红色的CoCl2水溶液;50mg的AB和10mg的NaBH4溶解于5mL的蒸馏水,在25℃下,将该溶液加入到粉红色的CoCl2水溶液中磁力搅拌均匀,粉红色溶液迅速变为黑色悬浮液,如图3所示,X射线光电子能谱(XPS)结果显示,黑色悬浮颗粒即为Co纳米金属催化剂;在AB溶液制氢结束后,将水洗过的黑色悬浮Co纳米颗粒放在蒸馏水中,在空气氛下搅拌该溶液200分钟,发现黑色悬浮液仍然没有变化。说明Co纳米颗粒在没有C1-、BO2 -和NH4 +存在的空气中,不能实现纳米金属Co和Co2+相互转换,不能使纳米Co催化剂循环使用时实现自保护功能。 Dissolve 0.03 mmol of CoCl 2 6H 2 O in 5 mL of distilled water to obtain a pink CoCl 2 aqueous solution; 50 mg of AB and 10 mg of NaBH 4 are dissolved in 5 mL of distilled water, and add this solution to the pink color at 25 °C In the colored CoCl2 aqueous solution, the magnetic force stirs evenly, and the pink solution rapidly becomes a black suspension, as shown in Figure 3, X-ray photoelectron spectroscopy (XPS) results show that the black suspended particles are Co nanometer metal catalysts; in the AB solution After the hydrogen production was finished, the water-washed black suspended Co nanoparticles were placed in distilled water, and the solution was stirred for 200 minutes under an air atmosphere, and it was found that the black suspension remained unchanged. It shows that Co nanoparticles cannot realize the interconversion between nano-metal Co and Co 2+ in the air without C1 - , BO 2 - and NH 4 + , and cannot realize the self-protection function when the nano-Co catalyst is recycled.
比较实施例3 Comparative Example 3
将0.03mmol的CoCl2·6H2O溶解于5mL的蒸馏水中,得到粉红色的CoCl2水溶液;50mg的AB和10mg的NaBH4溶解于5mL的蒸馏水,在25℃下,将该溶液加入到粉红色的CoCl2水溶液中磁力搅拌均匀,粉红色溶液迅速变为黑色悬浮液,如图3所示,X射线光电子能谱(XPS)结果显示,黑色悬浮颗粒即为Co纳米金属催化剂;在AB制氢结束后,将水洗过的黑色悬浮Co纳米颗粒放在PH=9.4的氨水中,在空气氛下搅拌该溶液200分钟,发现黑色悬浮液仍然没有变化。说明Co纳米颗粒在有NH4 +存在的空气中,不能实现纳米金属Co和Co2+相互转换,不能使纳米Co催化剂循环使用时实现自保护功能。 Dissolve 0.03 mmol of CoCl 2 6H 2 O in 5 mL of distilled water to obtain a pink CoCl 2 aqueous solution; 50 mg of AB and 10 mg of NaBH 4 are dissolved in 5 mL of distilled water, and add this solution to the pink color at 25 °C In the colored CoCl 2 aqueous solution, the magnetic force stirred evenly, and the pink solution quickly turned into a black suspension, as shown in Figure 3, and the X-ray photoelectron spectroscopy (XPS) results showed that the black suspended particles were Co nano-metal catalysts; After the hydrogen was over, the water-washed black suspended Co nanoparticles were placed in ammonia water at pH = 9.4, and the solution was stirred for 200 min under an air atmosphere, and it was found that the black suspension remained unchanged. It shows that Co nanoparticles cannot realize the interconversion between nano-metal Co and Co 2+ in the air with NH 4 + , and cannot realize the self-protection function when the nano-Co catalyst is recycled.
比较实施例4(本发明的实施例) Comparative example 4 (embodiment of the present invention)
将0.03mmol的CoCl2·6H2O溶解于5mL的蒸馏水中,得到粉红色的CoCl2水溶液;50mg的AB和10mg的NaBH4溶解于5mL的蒸馏水,在25℃下,将该溶液加入到粉红色的CoCl2水溶液中磁力搅拌均匀,粉红色溶液迅速变为黑色悬浮液,如图3所示,X射线光电子能谱(XPS)结果显示,黑色悬浮颗粒即为Co纳米金属催化剂,初始反应产生的Co纳米粒子尺寸为20nm左右并且团聚到一起像纳米链结构,如图5a所示;在AB溶液制氢结束后,在25℃下,将黑色悬浮液在空气中磁力搅拌30分钟后,黑色悬浮液变成了粉红色液体。50mg的AB和10mg的NaBH4溶解于5mg的蒸馏水,将该溶液倒入粉红色溶液中,粉红色溶液再次变为黑色悬浮液;发明用了紫外可见吸收光谱(UV-Vis)来检测转变(图2)。在波长为510nm上,我们看到了与CoCl2相对应的吸收峰(图2a),加入溶解于5mL蒸馏水的50mg的AB和10mg的NaBH4后,,该吸收峰消失,说明Co2+离子转变成了Co纳米颗粒(图2b)。当黑色悬浮液转变成清晰的粉红色溶液后,510nm处的吸收峰再次出现(图2c),说明纳米金属Co再次转变成纳米Co2+离子,在波长为420nm处由于新的反应产物离子的产生而产生了新的吸收峰。此次纳米Co催化AB制氢过程的制氢量(mL)与时间(分钟)图如图4a所示,初始还原的Co纳米颗粒催化AB水解制氢能够在11分钟内完成,25℃下产生氢气的量为125mL。 Dissolve 0.03 mmol of CoCl 2 6H 2 O in 5 mL of distilled water to obtain a pink CoCl 2 aqueous solution; 50 mg of AB and 10 mg of NaBH 4 are dissolved in 5 mL of distilled water, and add this solution to the pink color at 25 °C Magnetically stir the colored CoCl 2 aqueous solution evenly, and the pink solution quickly turns into a black suspension, as shown in Figure 3. X-ray photoelectron spectroscopy (XPS) results show that the black suspended particles are Co nano-metal catalysts, and the initial reaction produces The size of the Co nanoparticles is about 20nm and they are agglomerated together like a nanochain structure, as shown in Figure 5a; after the hydrogen production of the AB solution is completed, the black suspension is magnetically stirred in the air for 30 minutes at 25 ° C, and the black The suspension turned into a pink liquid. 50 mg of AB and 10 mg of NaBH were dissolved in 5 mg of distilled water, and the solution was poured into a pink solution, which turned into a black suspension again; the invention used ultraviolet - visible absorption spectroscopy (UV-Vis) to detect the transformation ( figure 2). At a wavelength of 510nm, we saw an absorption peak corresponding to CoCl 2 (Fig. 2a). After adding 50 mg of AB and 10 mg of NaBH 4 dissolved in 5 mL of distilled water, the absorption peak disappeared, indicating that the Co 2+ ion was transformed into into Co nanoparticles (Fig. 2b). When the black suspension turned into a clear pink solution, the absorption peak at 510nm appeared again (Figure 2c), indicating that the nano-metallic Co was transformed into nano-Co 2+ ions again, and at the wavelength of 420nm due to the new reaction product ion resulting in a new absorption peak. The graph of hydrogen production (mL) and time (minutes) of the nano-Co catalyzed AB hydrogen production process is shown in Figure 4a. The initial reduction of Co nanoparticles catalyzed AB hydrolysis hydrogen production can be completed within 11 minutes. The amount of hydrogen gas was 125 mL.
比较实施例5 Comparative Example 5
将0.03mmol的CoCl2·6H2O溶解于5mL的蒸馏水中,得到粉红色的CoCl2水溶液;50mg的AB和10mg的NaBH4溶解于5mL的蒸馏水,在25℃下,将该溶液加入到粉红色的CoCl2水溶液中磁力搅拌均匀,粉红色溶液迅速变为黑色悬浮液,如图3所示,X射线光电子能谱(XPS)结果显示,黑色悬浮颗粒即为Co纳米金属催化剂,初始反应产生的Co纳米粒子尺寸为20nm左右并且团聚到一起像纳米链结构,如图5a所示;在AB溶液制氢结束后,在25℃下,将黑色悬浮液在空气中磁力搅拌30分钟后,黑色悬浮液变成了粉红色液体。这说明Co纳米粒子经过氧化刻蚀转化为具有自保护功能的Co2+离子后,室温空气下保存7天,加入溶解于5mL蒸馏水的50mg的AB和10mg的NaBH4后,再次用被还原成Co纳米颗粒并且应用到同样的催化反应中。如此重复5次,共35天,结果第五次再生的Co纳米颗粒和初始反应的Co纳米颗粒有着相同的反应活性,这次催化AB水解制氢能够在11.4分钟内完成,产生氢气的量为125mL。 Dissolve 0.03 mmol of CoCl 2 6H 2 O in 5 mL of distilled water to obtain a pink CoCl 2 aqueous solution; 50 mg of AB and 10 mg of NaBH 4 are dissolved in 5 mL of distilled water, and add this solution to the pink color at 25 °C Magnetically stir the colored CoCl 2 aqueous solution evenly, and the pink solution quickly turns into a black suspension, as shown in Figure 3. X-ray photoelectron spectroscopy (XPS) results show that the black suspended particles are Co nano-metal catalysts, and the initial reaction produces The size of the Co nanoparticles is about 20nm and they are agglomerated together like a nanochain structure, as shown in Figure 5a; after the hydrogen production of the AB solution is completed, the black suspension is magnetically stirred in the air for 30 minutes at 25 ° C, and the black The suspension turned into a pink liquid. This shows that after Co nanoparticles are converted into Co 2+ ions with self-protection function through oxidation etching, they are stored in air at room temperature for 7 days, and after adding 50 mg of AB and 10 mg of NaBH 4 dissolved in 5 mL of distilled water, they are reduced to Co nanoparticles and applied to the same catalytic reaction. This was repeated 5 times for a total of 35 days. As a result, the regenerated Co nanoparticles for the fifth time had the same reactivity as the Co nanoparticles for the initial reaction. This time, the catalyzed hydrolysis of AB to produce hydrogen could be completed within 11.4 minutes, and the amount of hydrogen produced was 125mL.
比较实施例6 Comparative Example 6
将0.03mmol的CoCl2·6H2O溶解于5mL的蒸馏水中,得到粉红色的CoCl2水溶液;50mg的AB和10mg的NaBH4溶解于5mL的蒸馏水,在25℃下,将该溶液加入到粉红色的CoCl2水溶液中磁力搅拌均匀,粉红色溶液迅速变为黑色悬浮液,如图3所示,X射线光电子能谱(XPS)结果显示,黑色悬浮颗粒即为Co纳米金属催化剂,初始反应产生的Co纳米粒子尺寸为20nm左右并且团聚到一起像纳米链结构,如图5a所示;在AB溶液制氢结束后,在25℃下,将黑色悬浮液在空气中磁力搅拌30分钟后,黑色悬浮液变成了粉红色液体。这说明Co纳米粒子经过氧化刻蚀转化为具有自保护功能的Co2+离子后,室温空气下保存7天,加入溶解于5mL蒸馏水的50mg的AB和10mg的NaBH4后,再次被还原成Co纳米颗粒并且应用到同样的催化反应中。如此重复10次,共70天,结果第10次再生的Co纳米颗粒和初始反应的Co纳米颗粒有着相同的反应活性,第10次反应后的Co纳米颗粒的TEM知(图5b),Co纳米颗粒为4nm左右,这次催化AB水解制氢能够在11分钟内完成,25℃下产生氢气的量为125mL。 Dissolve 0.03 mmol of CoCl 2 6H 2 O in 5 mL of distilled water to obtain a pink CoCl 2 aqueous solution; 50 mg of AB and 10 mg of NaBH 4 are dissolved in 5 mL of distilled water, and add this solution to the pink color at 25 °C Magnetically stir the colored CoCl 2 aqueous solution evenly, and the pink solution quickly turns into a black suspension, as shown in Figure 3. X-ray photoelectron spectroscopy (XPS) results show that the black suspended particles are Co nano-metal catalysts, and the initial reaction produces The size of the Co nanoparticles is about 20nm and they are agglomerated together like a nanochain structure, as shown in Figure 5a; after the hydrogen production of the AB solution is completed, the black suspension is magnetically stirred in the air for 30 minutes at 25 ° C, and the black The suspension turned into a pink liquid. This shows that after Co nanoparticles are converted into Co 2+ ions with self-protection function through oxidation etching, they are stored in air at room temperature for 7 days, and after adding 50 mg of AB and 10 mg of NaBH 4 dissolved in 5 mL of distilled water, they are reduced to Co again. nanoparticles and applied to the same catalytic reaction. This was repeated 10 times for a total of 70 days. As a result, the regenerated Co nanoparticles for the 10th time had the same reactivity as the Co nanoparticles for the initial reaction. The TEM of the Co nanoparticles after the 10th reaction (Fig. The particle size is about 4nm. The catalytic AB hydrolysis to produce hydrogen can be completed within 11 minutes, and the amount of hydrogen produced at 25°C is 125mL.
比较实施例7 Comparative Example 7
将0.03mmol的CoCl2·6H2O溶解于5mL的蒸馏水中,得到粉红色的CoCl2水溶液;50mg的AB和10mg的NaBH4溶解于5mL的蒸馏水,在25℃下,将该溶液加入到粉红色的CoCl2水溶液中磁力搅拌均匀,粉红色溶液迅速变为黑色悬浮液,如图3所示,X射线光电子能谱(XPS)结果显示,黑色悬浮颗粒即为Co纳米金属催化剂,初始反应产生的Co纳米粒子尺寸为20nm左右并且团聚到一起像纳米链结构,如图5a所示;在空气中,将水洗后的Co纳米颗粒储存在纯水中7天,然后将该催化剂颗粒应用到AB的催化制氢反应中(没有NaBH4的反应),反应只能在216分钟内完成(如图4插入图所示)。总的来说,金属-金属离子的 可逆转变能够作为一种新的方法来克服Co纳米粒子的氧化钝化,长期在空气中保存后,Co纳米催化剂仍然拥有很高的活性,从而使Co纳米催化剂能够大量的商业应用。 Dissolve 0.03 mmol of CoCl 2 6H 2 O in 5 mL of distilled water to obtain a pink CoCl 2 aqueous solution; 50 mg of AB and 10 mg of NaBH 4 are dissolved in 5 mL of distilled water, and add this solution to the pink color at 25 °C Magnetically stir the colored CoCl 2 aqueous solution evenly, and the pink solution quickly turns into a black suspension, as shown in Figure 3. X-ray photoelectron spectroscopy (XPS) results show that the black suspended particles are Co nano-metal catalysts, and the initial reaction produces The size of the Co nanoparticles is about 20nm and agglomerated together like a nanochain structure, as shown in Figure 5a; in air, the washed Co nanoparticles were stored in pure water for 7 days, and then the catalyst particles were applied to the AB In the catalytic hydrogen production reaction (the reaction without NaBH 4 ), the reaction can only be completed within 216 min (as shown in the inset of Fig. 4). In general, the metal-metal ion reversible transformation can be used as a new method to overcome the oxidation passivation of Co nanoparticles. After long-term storage in air, Co nanocatalysts still have high activity, so that Co The catalyst is capable of numerous commercial applications.
虽然本发明已经参考实施例被详细的描述了,对于本领域的普通技术人员来说可以理解,在所付权利要求范围内,可以进行部分细节上的变动。 Although the invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that changes in some of the details may be made within the scope of the appended claims. the
工业应用: Industrial application:
用金属-金属离子可逆转变法制备纳米Co催化剂可以简单有效的避免非贵金属催化剂的氧化钝化,使其易于保存,实现自身的保护作用并且使纳米Co催化剂具有很高的循环稳定性。极大的促进了车载移动氢源材料中储氢-放氢的实际应用。 The preparation of nano-Co catalysts by metal-metal ion reversible transformation can simply and effectively avoid the oxidation passivation of non-noble metal catalysts, make them easy to store, realize their own protection and make nano-Co catalysts have high cycle stability. It has greatly promoted the practical application of hydrogen storage-dehydrogenation in vehicle-mounted mobile hydrogen source materials. the
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CN111270263A (en) * | 2020-03-04 | 2020-06-12 | 太原理工大学 | Cobaltosic oxide electrode with foam nickel loaded with rich boron and oxygen vacancies and preparation method thereof |
CN114713283A (en) * | 2022-04-26 | 2022-07-08 | 沈阳药科大学 | Efficient and selective catalytic system of cobalt nanoparticles and method for reducing alkynes to (Z)-alkenes |
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
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CN109589975A (en) * | 2018-12-25 | 2019-04-09 | 吉林大学 | A kind of rhodium nanocatalyst and its preparation method and application of molybdenum oxide modification |
CN111270263A (en) * | 2020-03-04 | 2020-06-12 | 太原理工大学 | Cobaltosic oxide electrode with foam nickel loaded with rich boron and oxygen vacancies and preparation method thereof |
CN111270263B (en) * | 2020-03-04 | 2022-04-19 | 太原理工大学 | Cobaltosic oxide electrode with foam nickel loaded with rich boron and oxygen vacancies and preparation method thereof |
CN114713283A (en) * | 2022-04-26 | 2022-07-08 | 沈阳药科大学 | Efficient and selective catalytic system of cobalt nanoparticles and method for reducing alkynes to (Z)-alkenes |
CN114713283B (en) * | 2022-04-26 | 2024-05-14 | 沈阳药科大学 | Cobalt nanoparticle high-efficiency selective catalytic system and method for generating (Z) -alkene by reducing alkyne by using same |
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