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NaCl对离子液体中电解精炼铝的影响 总被引:1,自引:0,他引:1
研究了添加NaCl对BMIC-AlCl3离子液体电导率及电解精炼铝的影响,分析了阴极电流效率、电流密度的变化,并通过扫描电镜和能谱分析研究了沉积层的形貌及成分。结果表明,添加NaCl可以提高电解液的电导率,阴极电流效率也可提高至82%~96%,但电流密度则有所降低;添加NaCl还可以改善电解精炼铝的沉积质量,使晶粒尺寸... 相似文献
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非均相电解Mn^2+的电极过程动力学研究 总被引:7,自引:0,他引:7
选择Pb-Sb-As合金为研究电极,通过阳极极化曲线确定了非均相电解氧化Mn62+电极过程机理,即为在阳极上存在液相和固相两个反应;并确定了40%H2SO4介质中Mn/Mn体系的条件电极电势为0.886V。采用旋转圆盘电极研究得到在非均相电解MnSO4过程中电极过程控制步骤为电荷传递-浓度极化混合控制步骤,并确定了电极反应的动力学参数。 相似文献
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在稳流条件下,考察了KNO3体系中离子液体辅助煤浆电解脱硫效果.研究了煤浆电解过程中离子液体结构、浓度、温度和时间对脱硫率的影响.当咪唑类离子液体有机结构相同时,不同阴离子脱硫率由高到低顺序为:Br- >BF4- >Cl-;当阴离子同为Br-时,咪唑脱硫效果优于吡啶.随着吡啶类离子液体([BPy]Br)浓度增加,脱硫率先增加,在0.3 mol/L处达到最大值,而后下降.此外,脱硫率随温度和时间增加而增大.最后,通过X射线光电子能谱(XPS)分析技术对实验前后煤中有机硫形态进行了分析.结果表明,噻吩主要通过萃取-氧化反应脱除,而其他形式有机硫(如硫醚、亚砜)则主要通过促进氧化及水解反应脱除. 相似文献
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吴永宁 《理化检验(化学分册)》2005,41(9):691-692
文献[1]报道用恒电流电解溶样测定钢中锰量。但用于测定钢中磷时,由于铁在阳极的水解及磷酸根离子的吸附,使电解过程难于控制。本文讨论磷酸根在电极上某些特殊性质及其用电解法进行分析所采取的措施。 相似文献
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通过在氧化还原稳定的钙钛矿材料钛铌酸盐的B位晶格中掺杂具有氧化还原活性的锰元素提高固体氧化物电解池复合电极电催化性能.研究发现,锰元素成功取代钛铌酸盐B位的Ti/Nb.掺杂后的样品的离子电导率在800℃下的氧化气氛和还原气氛下的离子电导率分别提高了约1和0.5个数量级.基于掺杂后的钛铌酸盐基复合阴极,氧离子传导型固体氧化物电解池电解水蒸汽的电流效率在有和无还原气体保护下分别提高了25%和30%. 相似文献
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选取铝、铜、镁、钙、铁、锰和锌等7种元素的9条谱线,研究电感耦合等离子体原子发射光谱法对其测定时易电离元素钾、钠的基体干扰。结果表明:易电离元素对待测元素具有较明显的干扰作用,而增大射频发射功率及降低雾化器压力可有效地抑制易电离元素对待测元素的干扰。 相似文献
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初中化学教材中的水电解器在使用时存在一些缺陷,常出现实验失败或现象不明显等情况。利用生活中的一些废弃材料自制水电解器,可获得较好的实验教学效果。 相似文献
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设计了一个全新的电解水演示实验,将太阳能电池、电解水制氢、氢氧燃料电池一体化构成一个整体的演示实验,可以帮助学生系统了解与氢相关联的储能用能技术和基于氢的洁净能源的开发和应用,激发学生利用化学知识服务于国家绿色发展理念的使命担当。 相似文献
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Liqiang Yin Dr. Rong Ren Dr. Lanlan He Wentao Zheng Dr. Yu Guo Dr. Linqin Wang Dr. Husileng Lee Dr. Jian Du Dr. Zhiheng Li Dr. Tang Tang Guoheng Ding Prof. Dr. Licheng Sun 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(19):e202400764
Anion exchange membranes (AEMs) are core components in anion exchange membrane water electrolyzers (AEM-WEs). However, the stability of functional quaternary ammonium cations, especially under high temperatures and harsh alkaline conditions, seriously affects their performance and durability. Herein, we synthesized a 1-methyl-3,3-diphenylquinuclidinium molecular building unit. Density functional theory (DFT) calculations and accelerated aging analysis indicated that the quinine ring structure was exceedingly stable, and the SN2 degradation mechanism dominated. Through acid-catalyzed Friedel–Crafts polymerization, a series of branched poly(aryl-quinuclidinium) (PAQ-x) AEMs with controllable molecular weight and adjustable ion exchange capacity (IEC) were prepared. The stable quinine structure in PAQ-x was verified and retained in the ex situ alkaline stability. Furthermore, the branched polymer structure reduces the swelling rate and water uptake to achieve a tradeoff between dimensional stability and ionic conductivity, significantly improving the membrane's overall performance. Importantly, PAQ-5 was used in non-noble metal-based AEM-WE, achieving a high current density of 8 A cm−2 at 2 V and excellent stability over 2446 h in a gradient constant current test. Based on the excellent alkaline stability of this diaryl-quinuclidinium group, it can be further considered as a multifunctional building unit to create multi-topological polymers for energy conversion devices used in alkaline environments. 相似文献
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石墨电极是中学电化学实验中常用的一种惰性电极,但其在电解水实验中造成氧气体积偏小和石墨阳极更易损耗的原因目前还不清楚。利用手持技术探究石墨电极电解水的实验,并深入研究造成偏差的原因。实验结果表明石墨电极对氢气吸附能力大于氧气,阳极电解产生的自由基与石墨反应是造成气体体积偏差和阳极损耗的主要原因。 相似文献
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与传统化石能源制氢技术相比,利用可再生能源驱动电解水制氢技术具有绿色可持续和制氢效率高等优势,被认为是目前最具前景的制氢方式。然而, 由于电解水两极反应动力学缓慢、 催化剂稳定性较差, 限制了其大规模发展。此外, 阳极析氧反应存在较高的过电势, 从而导致当前制氢能耗与成本较高, 严重制约了其商业化应用。 为了解决上述问题与挑战,本文对当前发展较为成熟的碱性电解水技术进行了综合讨论与分析。 首先, 对电解水发展历程中的重要节点进行了总结, 便于读者了解该领域。进一步, 从电催化剂、 电极、 反应和系统的角度深入总结了提升电解水制氢性能的有效策略。作者分别介绍了近年来层状双金属氢氧化物基电解水催化剂、电解水制氢耦合氧化反应以及可再生能源驱动的电解水系统的重要研究进展; 同时对结构化催化剂在电解水应用中的构效关系进行了深入分析。最后, 对该领域存在的挑战和未来发展方向进行了展望,希望能为氢能的发展和推广提供一定的思路。 相似文献
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Dorota Swiatla-Wojcik 《Research on Chemical Intermediates》2009,35(4):519-530
The effect of pH and associated ionic strength on the primary yields in the radiolysis of pressurised water has been assessed
by diffusion-kinetic calculations for temperatures in the range 100–300°C. Account has been taken for ionic strength I up to 0.1 mol kg−1, assuming that the counter ions of H+ in acid solutions and of OH− in base solutions have unit charge. In acid solutions, the H+ ions react with e−
aq. The decrease in G(e−
aq) and the increase in G(H) with decreasing pH becomes substantial for [H+] ≥ 1 × 10−4 m, but the primary yields of oxidising species are almost constant. In alkaline solutions, the OH− anions affect the spur chemistry of radiation-generated protons and hydroxyl radicals for [OH−] ≥ 1 × 10−4 m. The scavenging of H atoms and hydrogen peroxide becomes significant for [OH−] ≥ 1 × 10−2 m. The total yields G(OH) + G(O−) and G(H2O2) + G(HO2
−) are independent of base concentration below 0.01 m. In more alkaline solutions, G(OH) + G(O−) increases, whereas G(H2O2) + G(HO2
−) decreases with increasing [OH−]. Calculations showed the substantial yield of the reaction O− + e−
aq in 0.1 m base solution. Spur chemistry in alkaline hydrogenated water is not affected by the presence of H2 if less than 0.001 m of hydrogen is added. 相似文献
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Dr. Rui Xiang Dr. Lishan Peng Prof. Zidong Wei 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(42):9799-9815
Interface modulation, as an old concept of heterogeneous catalysis, represents an emerging, fast-growing and exciting direction in the field of water electrolysis. Over the past five years, diverse hetero-nanostructures have been synthesised as water electrolysis catalysts by taking advantage of interface modulation. However, it seems that the performance (i.e., efficiency and durability) of these materials needs to be further improved. Therefore, a comprehensive summary of recent achievements and the challenging issues concerning the regulation of material functionalities through interface modulation is necessary and helpful. Herein, firstly, the fundamentals of water electrolysis are outlined, and then the delicate design and fine control of well-defined interfaces, as well as related mechanisms for performance improvement are discussed. Finally, future opportunities and challenges in the everlasting pursuit of highly efficient and robust water electrolysis catalysts are highlighted. 相似文献