论文总字数：18875字

摘 要

氧阴极还原法产过氧化氢（H₂O₂）绿色无污染，且可以避免H₂O₂在生产、运输和储存过程的安全风险，是国内外的研究热点。然而该法氧气利用率低，且需要选用合适的电极材料。硝酸作为一种强氧化试剂，氧化能力强，可以增加电极表面的含氧官能团，增强氧2电子转移的选择性，从而降低氧气利用率低的问题。本论文以常用的石墨板电极作为阴极材料，钌铱电极为阳极，通过硝酸对石墨板进行改性，分别通过控制改性温度、时间和浓度以及电流密度等条件考察改性电极产H₂O₂的变化，并考察电极重复使用的稳定性，探讨影响机制。

实验结果表明，用硝酸进行改性，电流密度、改性时间、温度、浓度对石墨电极产H₂O₂性能都有影响。当电流密度为5mA/cm²，产H₂O₂量最多，因此作为最佳电流密度用于后续试验。当硝酸的改性时间设在2h、温度设在20℃、浓度设在68%时，产H₂O₂效能最佳，产量最大为9.7mg/L。使用后的电极经纯水清洗、晾干后，进行重复使用稳定性试验，发现重复使用后产H₂O₂的量都不如第一次，推测其稳定性不太好。通过测定改性前后石墨板的接触角，发现改性后的石墨板亲水性能增强。且改性温度越高，时间越长，硝酸浓度越低时，亲水性能越好。

关键词：过氧化氢 改性 石墨 亲水性 稳定性

Study on hydrogen peroxide production by nitric acid modified graphite electrode

Abstract

The production of hydrogen peroxide (H₂O₂) by oxygen cathodic reduction is green and pollution-free, and it can avoid the safety risk of H₂O₂ in production, transportation and storage. However, due to the low oxygen utilization rate, suitable electrode materials should be selected. Nitric acid, as a strong oxidation reagent, has a strong oxidation capacity, which can increase the oxygen-containing functional groups on the electrode surface, enhance the selectivity of oxygen-2 electron transfer, and thus reduce the problem of low oxygen utilization rate. In this paper, the commonly used graphite plate electrode was used as the cathode material, ruthenium-iridium electrode was used as the anode, and the graphite plate was modified by nitric acid. The change of H₂O₂ production of the modified electrode was investigated by controlling the modified temperature time, concentration and current density, and the stability of the electrode was investigated for the influence mechanism.

The experimental results show that H₂O₂ production performance of graphite electrode is affected by the time and temperature concentration of current density modification with nitric acid. When the current density is 5mA/cm², the maximum amount of H₂O₂ is produced, so it is used as the optimal current density for subsequent tests. When the modification time of nitric acid is set at 2h and the temperature is set at 20℃ and the concentration is set at 68%, the yield of H₂O₂ is the best and the maximum is 9.7mg/L. After the electrode was cleaned and dried with pure water, the stability test of repeated use was carried out. It was found that the amount of H₂O₂ produced after repeated use was not as good as that of the first time, so it was speculated that the stability of the electrode was not very good. By measuring the contact angle of the graphite plate before and after modification, it is found that the hydrophilicity of the modified graphite plate can be enhanced, and the higher the modified temperature, the longer the modified time, and the lower the concentration of nitric acid, the better the hydrophilicity can be.

Key words: hydrogen peroxide; modification; graphite; hydrophilicity; 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 异丙醇法 2

1.2.3 电解法 2

1.2.4 氧阴极还原法 2

1.3碳材料改性方法研究进展 3

1.4硝酸改性碳材料工艺研究进展 4

1.5本文研究意义和研究内容 5

1.5.1 研究意义 5

1.5.2 研究内容 5

第二章 实验部分 6

2.1 主要试剂、仪器 6

2.1.1试剂 6

2.1.2仪器 6

2.1.3实验装置 7

2.2 实验步骤 7

2.2.1 电极的制备 7

2.2.2 H₂O₂的测定 7

2.2.3 H₂O₂产生实验 8

2.2.4 单因素实验 8

2.2.5 重复稳定性实验 10

2.2.6 接触角测定 10

第三章 实验结果与分析讨论 11

3.1 实验现象 11

3.2 实验结果分析 11

3.2.1 不同电流密度对H₂O₂产量的影响 11

3.2.2 不同改性时间对H₂O₂产量的影响 12

3.2.3 不同改性温度对H₂O₂产量的影响 13

3.2.4 不同硝酸浓度对H₂O₂产量的影响 15

3.2.5 稳定性结果分析 16

3.2.6 接触角测定结果分析 17

第四章 总结与展望 19

4.1 总结 19

4.2 展望 19

参考文献 21

致谢 24

第一章 绪论

1.1前言

过氧化氢（H₂O₂）也叫作双氧水，一般作为强氧化剂，广泛应用在食品、医药、电子、化工、环境治理等领域。在化工生产领域，过氧化氢自二十世纪九十年代起被广泛应用于有机合成的反应，作为清洁生产的氧化剂，运用在醇类、烯烃类、羟基等化合物中，不仅拓宽有机合成的运用范围，还保障了过程的安全和环保 ^[1]；在环境治理方面，过氧化氢不仅无污染，而且可以有效处理工业产生的三废，主要包括对各类废水进行除毒、去味、脱色，对废气的脱除，且不产生二次污染，大大改善了环境质量^[2]。目前国内环保行业是双氧水最大潜在的消费市场，近年来逐步采用双氧水对城市用水进行消毒，市场前景一片光明^[3]。

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