论文总字数：19630字

摘 要

在目前的产过氧化氢领域内，氧阴极还原法是目前比较有应用前景的一种方法，能够避免过氧化氢在运输、储存和使用过程中易爆和易分解的风险。石墨质量很轻，导电性好，成本低廉，价格稳定适中，故常用作气体扩散电极的催化剂。本实验的阳极材料为钌铱电极，阴极材料为石墨碳毡，用次氯酸钠溶液对碳毡电极进行改性，研究电流密度、时间、温度、pH值等条件对于石墨碳毡表面的亲疏水性以及产过氧化氢的影响，并考察石墨碳毡电极的重复使用稳定性，探讨其受影响作用的机制。

实验结果表明，用次氯酸钠溶液进行改性后，电流密度、时间、温度、pH值等对产H₂O₂性能都有影响。当电流密度设为10mA/cm²时，产H₂O₂量最多，可达到13.33mg/L，故将后续实验中的电流密度值都设定为10mA/cm²。实验中初步确定了产H₂O₂的优化条件为：曝气量为2000mL/min、电解液pH=3、电流密度为10mA/cm²。当用次氯酸钠改性2h时，产H₂O₂的效能最好，H₂O₂产量可达到5.15mg/L。当改性温度为60℃时，H₂O₂产量最大为8.48mg/L。碳毡电极产过氧化氢受次氯酸钠溶液的pH值影响很大，在pH=13时效果最好，产量可达到8.48mg/L。使用后的电极经过纯水冲洗、晾干后，进行重复使用稳定性实验，发现之后每一次产H₂O₂量都不如上一次，推测用次氯酸钠改性后，石墨碳毡的稳定性变差。

关键词：石墨碳毡 过氧化氢 氧气还原 亲疏水性 稳定性

Study on hydrogen peroxide production of graphite carbon felt modified by sodium hypochlorite

Abstract

Oxygen cathodic reduction is a promising method to produce hydrogen peroxide at present, which can avoid the risk of explosion and easy decomposition of hydrogen peroxide in the process of transportation, storage and use. Graphite is very light, good electrical conductivity, low cost, moderate price stability, so it is often used as a catalyst for gas diffusion electrode. In this experiment, ruthenium iridium electrode is used for the anode, and graphite carbon felt electrode for cathode. Graphite carbon felt electrode is modified with sodium hypochlorite solution. The effect of current density, modification time, temperature, and pH on graphite carbon felt hydrophobicity and H₂O₂ production is studied. The repeated use stability of graphite carbon felt electrode is investigated, and influence mechanisms of modification is discussed.

The results show that the current density, sodium hypochlorite modification time, temperature and pH value all have a influence on the graphite carbon felt electrode performance of H₂O₂ production. When the current density is set to 10mA/cm², the maximum amount of H₂O₂ can be produced, which reaches 13.33mg/L. Therefore, the current density values in subsequent experiments are all set to 10mA/cm². In the experiment, the optimized conditions for the production of H₂O₂ are preliminarily determined as follows: the aeration volume is 2000mL/min, the pH of electrolyte is 3, and the current density is 10mA/cm². When the modification time of sodium hypochlorite is 2h, the efficiency of producing H₂O₂ is the best, and the concentration of H₂O₂ can reach 5.15mg/L. When the modified temperature is 60℃, the maximum yield of H₂O₂ is 8.48mg/L. The production of hydrogen peroxide by carbon felt electrode is greatly affected by the pH value of sodium hypochlorite solution, and the best result is achieved at pH=13, with the yield reaching 8.48mg/L. After the electrode is washed with pure water and dried by air, the stability experiment of

repeated use is carried out. It is found that the amount of H₂O₂ production is lower than that of the last time. It is speculated that the stability of graphite carbon felt is not good after being modified with sodium hypochlorite.

Key words: graphite carbon felt; hydrogen peroxide; oxygen reduction ; hydrophilic and hydrophobic ; stability

目 录

摘要 I

Abstract II

第一章 绪论 1

1.1前言 1

1.2过氧化氢的生产方法 1

1.2.1蒽醌法 1

1.2.2氢氧直接合成法 1

1.2.3电解法 1

1.2.4氧阴极还原法 2

1.2.5异丙醇法 2

1.3氧阴极还原法现阶段研究进展 2

1.3.1 电极材料的研究 2

1.3.2 其他影响因素研究 3

1.4次氯酸钠性质 3

1.5本文研究意义和研究内容 4

1.5.1 研究意义 4

1.5.2 研究内容 4

第二章 实验部分 5

2.1 主要试剂、仪器 5

2.1.1试剂 5

2.1.2仪器 5

2.1.3实验装置 6

2.2实验步骤 6

2.2.1电极制备 6

2.2.2 H₂O₂的测定 6

2.2.3 H₂O₂产生实验 7

2.2.4单因素实验 7

2.2.5 重复稳定性实验 8

2.2.6 亲疏水性 8

第三章 实验结果与分析讨论 10

3.1 单因素影响分析 10

3.1.1 电流密度对石墨碳毡产过氧化氢量的影响 10

3.1.2时间对石墨碳毡产过氧化氢量的影响 11

3.1.3 温度对石墨碳毡产过氧化氢量的影响 12

3.1.4 pH对石墨碳毡产过氧化氢量的影响 13

3.2重复稳定性实验 14

3.3 亲疏水性 15

第四章 总结与展望 17

4.1总结 17

4.2展望 18

参考文献 19

致谢 21

第一章 绪论

1.1 前言

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