葱基活性炭的制备及其在环保型新能源领域中的应用
发布时间：2018-08-19 20:50
【摘要】：随着全球经济、人口的快速增长，能源缺乏和环境危机已成为人们面临的主要问题，新型能源的开发迫在眉睫。超级电容器和直接甲酸燃料电池是两种目前备受各国政府重视的新型能量存储和转换工具。新能源的发展依赖于新材料的发现。作为一种多孔炭材料，活性炭用途广泛，其制备过程一直是研究的热点。 本文以可再生的生物质材料——葱叶为炭前驱体，在不添加任何其它活化剂的条件下，炭化活化同时进行，制备了孔径分布集中在0.6～1.2nm和3～5nm之间的多孔活性炭材料，并将其用作超级电容器的电极材料和直接甲酸燃料电池的催化剂载体，对其电化学性能进行了研究。作为一种生物质原材料，这是葱叶首次被用于超级电容电极材料和催化剂载体。分别采用扫描电子显微镜（SEM）、场发射扫描电子显微镜（FE-SEM）、能量色散X射线光谱（EDX）、火焰原子吸收光谱（FAAS)、X射线衍射（XRD）、热重分析（TGA）和氮气吸脱附等方法表征了葱基活性炭材料的形貌、成分、比表面积及孔径分布情况；通过循环伏安（CV）、交流阻抗（EIS）、恒流充放电（GCD）等电化学方法考察了材料的电化学性能。得到如下结论： （1）在葱叶中本身含有的微量矿物质如钙、钾等元素及其衍生物的作用下，可经一步炭化活化，将葱叶制备为具有较高比表面积的活性炭材料。在600℃、700℃、800℃的反应温度下，制得的活性炭比表面积分别为230.5m2·g-1，348.4m2·g-1和551.7m2·g-1，比表面积大小随反应温度的升高增大。同时，800℃下制得的活性炭的孔径分布更集中。 （2）葱基活性炭具有良好的电容性能。其循环伏安曲线的形状类似矩形、恒流充放电曲线为几乎对称的等腰三角形，，交流阻抗图中低频区部分曲线几乎垂直于横轴，表明葱基活性炭适于作为超级电容器电极材料。不同温度下制得的葱基活性炭的电容性能及电容值受其比表面积大小、孔径分布情况影响，比表面积越大、孔径分布越集中，电容性能越好。 （3）提出了效面积电容，计算并比较了多种生物质材料活性炭的有效面积电容。本实验制得的葱基活性炭的有效面积电容在0.2A·g-1的扫速下高达28.8μF·cm-2，几乎为其他材料的2倍，适用于各种小型电子设备。 （4）以葱基活性炭为载体的钯铜合金催化剂具有良好的甲酸氧化催化性能。催化剂中铜含量不同时催化性能有所不同，随铜含量的增多催化剂的电催化性能呈先上升后下降的趋势。结果表明催化剂中加入适量的铜可减少钯的用量，降低催化剂成本，同时有利于钯基催化剂催化性能的提高。
[Abstract]:With the rapid growth of global economy and population, energy shortage and environmental crisis have become the main problems faced by people. Supercapacitors and direct formic acid fuel cells are two new energy storage and conversion tools. The development of new energy depends on the discovery of new materials. As a porous carbon material, activated carbon has a wide range of applications, its preparation process has been the focus of research. In this paper, the porous activated carbon materials with pore size distribution between 0.6~1.2nm and 3~5nm were prepared by carbonization and activation of the regenerative biomass material, scallion leaves, without adding any other activators. It is used as electrode material of supercapacitor and catalyst carrier of direct formic acid fuel cell, and its electrochemical performance is studied. As a kind of biomass raw material, this is the first time that onion leaf is used as super capacitor electrode material and catalyst carrier. Scanning electron microscope (SEM), (SEM), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDX), (EDX), flame atomic absorption spectrum (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and nitrogen adsorption and desorption were used to characterize the morphology of scallion based activated carbon. Composition, specific surface area and pore size distribution, electrochemical properties of the materials were investigated by cyclic voltammetry (CV),) AC impedance (EIS), constant current charge-discharge (GCD). The conclusions are as follows: (1) under the action of trace minerals such as calcium, potassium and their derivatives in the leaves of onion, they can be carbonized and activated to form active carbon materials with high specific surface area. The specific surface area of activated carbon was 230.5m2 g-1348.4m2 g-1 and 551.7m2 g-1 at the reaction temperature of 600 鈩
本文编号：2192796
[Abstract]:With the rapid growth of global economy and population, energy shortage and environmental crisis have become the main problems faced by people. Supercapacitors and direct formic acid fuel cells are two new energy storage and conversion tools. The development of new energy depends on the discovery of new materials. As a porous carbon material, activated carbon has a wide range of applications, its preparation process has been the focus of research. In this paper, the porous activated carbon materials with pore size distribution between 0.6~1.2nm and 3~5nm were prepared by carbonization and activation of the regenerative biomass material, scallion leaves, without adding any other activators. It is used as electrode material of supercapacitor and catalyst carrier of direct formic acid fuel cell, and its electrochemical performance is studied. As a kind of biomass raw material, this is the first time that onion leaf is used as super capacitor electrode material and catalyst carrier. Scanning electron microscope (SEM), (SEM), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDX), (EDX), flame atomic absorption spectrum (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and nitrogen adsorption and desorption were used to characterize the morphology of scallion based activated carbon. Composition, specific surface area and pore size distribution, electrochemical properties of the materials were investigated by cyclic voltammetry (CV),) AC impedance (EIS), constant current charge-discharge (GCD). The conclusions are as follows: (1) under the action of trace minerals such as calcium, potassium and their derivatives in the leaves of onion, they can be carbonized and activated to form active carbon materials with high specific surface area. The specific surface area of activated carbon was 230.5m2 g-1348.4m2 g-1 and 551.7m2 g-1 at the reaction temperature of 600 鈩
本文编号：2192796
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