【摘要】：隨著全球經(jīng)濟(jì)、人口的快速增長(zhǎng)，能源缺乏和環(huán)境危機(jī)已成為人們面臨的主要問題，新型能源的開發(fā)迫在眉睫。超級(jí)電容器和直接甲酸燃料電池是兩種目前備受各國(guó)政府重視的新型能量存儲(chǔ)和轉(zhuǎn)換工具。新能源的發(fā)展依賴于新材料的發(fā)現(xiàn)。作為一種多孔炭材料，活性炭用途廣泛，其制備過(guò)程一直是研究的熱點(diǎn)。 本文以可再生的生物質(zhì)材料——蔥葉為炭前驅(qū)體，在不添加任何其它活化劑的條件下，炭化活化同時(shí)進(jìn)行，制備了孔徑分布集中在0.6～1.2nm和3～5nm之間的多孔活性炭材料，并將其用作超級(jí)電容器的電極材料和直接甲酸燃料電池的催化劑載體，對(duì)其電化學(xué)性能進(jìn)行了研究。作為一種生物質(zhì)原材料，這是蔥葉首次被用于超級(jí)電容電極材料和催化劑載體。分別采用掃描電子顯微鏡（SEM）、場(chǎng)發(fā)射掃描電子顯微鏡（FE-SEM）、能量色散X射線光譜（EDX）、火焰原子吸收光譜（FAAS)、X射線衍射（XRD）、熱重分析（TGA）和氮?dú)馕摳降确椒ū碚髁耸[基活性炭材料的形貌、成分、比表面積及孔徑分布情況；通過(guò)循環(huán)伏安（CV）、交流阻抗（EIS）、恒流充放電（GCD）等電化學(xué)方法考察了材料的電化學(xué)性能。得到如下結(jié)論： （1）在蔥葉中本身含有的微量礦物質(zhì)如鈣、鉀等元素及其衍生物的作用下，可經(jīng)一步炭化活化，將蔥葉制備為具有較高比表面積的活性炭材料。在600℃、700℃、800℃的反應(yīng)溫度下，制得的活性炭比表面積分別為230.5m2·g-1，348.4m2·g-1和551.7m2·g-1，比表面積大小隨反應(yīng)溫度的升高增大。同時(shí)，800℃下制得的活性炭的孔徑分布更集中。 （2）蔥基活性炭具有良好的電容性能。其循環(huán)伏安曲線的形狀類似矩形、恒流充放電曲線為幾乎對(duì)稱的等腰三角形，，交流阻抗圖中低頻區(qū)部分曲線幾乎垂直于橫軸，表明蔥基活性炭適于作為超級(jí)電容器電極材料。不同溫度下制得的蔥基活性炭的電容性能及電容值受其比表面積大小、孔徑分布情況影響，比表面積越大、孔徑分布越集中，電容性能越好。 （3）提出了效面積電容，計(jì)算并比較了多種生物質(zhì)材料活性炭的有效面積電容。本實(shí)驗(yàn)制得的蔥基活性炭的有效面積電容在0.2A·g-1的掃速下高達(dá)28.8μF·cm-2，幾乎為其他材料的2倍，適用于各種小型電子設(shè)備。 （4）以蔥基活性炭為載體的鈀銅合金催化劑具有良好的甲酸氧化催化性能。催化劑中銅含量不同時(shí)催化性能有所不同，隨銅含量的增多催化劑的電催化性能呈先上升后下降的趨勢(shì)。結(jié)果表明催化劑中加入適量的銅可減少鈀的用量，降低催化劑成本，同時(shí)有利于鈀基催化劑催化性能的提高。
[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

本文編號(hào)：2192796