氧气电催化剂中金属杂化碳协同界面研究及其锌空气电池中应用

时间：2021-06-10 10:10:44 来源：蒲公英阅读网 本文已影响人

相关热词搜索：催化剂 氧气 协同

　氧气电催化剂中的金属/ / 杂化碳协同界面研究及其在锌空气电池中的应用

　摘要 随着人类社会对可持续发展的要求越来越高和环境污染问题的日益严重，开发资源节约型和环境友好型的清洁能源对于社会经济的发展是至关重要的。可充电的锌空气电池在工作的时候涉及着充电过程的氧气析出反应（OER）和放电过程的氧气还原反应 (ORR)，而电解水装置涉及着正极的 OER 过程和负极的氢气析出（HER）过程。因此需要制备这种具有 OER/ORR 双功能和 OER/HER 双功能的电催化剂将其应用在能源装置上。然而铂基和钌基等贵金属催化剂具有杰出的性能，但由于资源缺乏，稳定性差和价格昂贵等缺点，而不能将其大规模地应用。因此需要去制备一些清洁，高效，无污染的非贵金属催化剂来替代那些贵金属催化剂。

　本文将通过三部分来探索被制备的金属/杂化碳电催化剂应用在锌空气电池中所表现出来的性能。首先，将尺寸受限的 Co-B-O 纳米片负载在 N，P 双掺杂的碳纳米片上并协同构建了 ORR，OER 和 HER 这种三功能的电催化剂。研究发现 B 元素不仅可以作为一种媒介将二种异质界面紧密地连接起来，同时作为一种还原剂也可以有效地抑制吡啶氮-氧化合物的含量。电化学测试表明所制备的 Co-B-O/NPC-50％催化剂具有优异的 ORR/OER/HER 催化活性。此外，对于某些能量转换设备，Co-B-O/NPC-50％催化剂还具有出色的适用性，其作为空气电极的锌空气电池拥有110.7 mW/cm2 的功率密度和超过 60 小时稳定的充放电循环。其次，探索了新颖的低成本生物质路线以制备形状可设计的 3D 碳泡沫。这种碳泡沫具有铁磁性，吸油性，重量轻的特点并具有与钴点，氮化石墨烯和纤维交织的三维碳网络。钴点被封装在外部的石墨化碳壳中。经过高温碳化的钴-碳纳米笼的核壳结构紧凑并通过 Co-N 键连接。Co-N 键进一步活化了碳壳并提高了 ORR 催化性能。电化学测试表明，Co-NCF催化剂表现出优异的 ORR 性能，具有更大的极限电流密度（5.74 mA/cm2 ），较高的起始电位（0.91 V），较高的半波电位（0.83 V）和长期稳定性。用作空气阴极催化剂的锌空气电池表现出高的功率密度和放电容量。最后，采用一种新颖的引入硼元素的方法制备了多掺杂的金属碳催化剂。研究发现仅引入少量的硼就可以显著地保留催化剂中的氮含量，钴与杂原子的结合能力得到改善。杂原子与金属钴之间的优化键合模式进一步提高了 ORR 的性能。电化学测试表明，所制备的 Co-NBSC 催化剂

　 的起始电势为 0.93 V，半波电势为 0.84 V，电流密度为 5.58 mA/cm2 ，并且具有出色的稳定性在碱性溶液中。另外，基于 Co-NBSC 的锌空气电池表现出 121.2 mW/cm2的功率密度和超过 30 h 的放电稳定性。上述被研究的金属/杂化碳电催化剂均在锌空气电池中表现出了优异的性能，具体体现在较高的功率密度，长时间的放电稳定性。这些为未来新型的电催化剂的制备提供了策略和思路。

　关键词

　：电催化剂；氧气还原反应；氧气析出反应；锌空气电池

　 Abstract As human society has higher and higher requirements for sustainable development and the problem of environmental pollution is becoming more and more serious, the development of resource-saving and environmentally-friendly clean energy is crucial for social and economic development. Rechargeable zinc-air batteries involve the oxygen evolution reaction (OER) during the charging process and the oxygen reduction reaction (ORR) during the discharge process, while electrolyzed water device involves the OER process of the positive electrode and the hydrogen evolution reaction (HER) of the negative electrode process. Therefore, it is necessary to prepare such an electrocatalyst with OER/ORR dual function and OER/HER dual function and apply it to energy devices. However, noble metal catalysts such as platinum-based and ruthenium-based have outstanding performance, but due to the lack of resources, poor stability and high cost, they can not be used on a large scale. Therefore, it is necessary to prepare some clean, efficient and pollution-free non-precious metal catalysts to replace those precious metal catalysts. This article will explore the performance of the prepared metal/hybridized carbon electrocatalyst in zinc air battery through three parts. First, Co-B-O nanosheets with limited size were supported on N, P double-doped carbon nanosheets, and the three-function electrocatalysts such as ORR, OER and HER were jointly constructed. The study found that element B can not only serve as a medium to tightly connect two heterogeneous interfaces, but also as a reducing agent can also effectively inhibit the content of pyridine nitrogen-oxygen compounds. Electrochemical tests show that the prepared Co-B-O/NPC-50% catalyst has excellent ORR/OER/HER catalytic activity. In addition, for certain energy conversion equipment, Co-B-O/NPC-50% catalyst also has excellent applicability. Its zinc-air battery as an air electrode has a power density of 110.7 mW/cm 2

　and a stable charge-discharge cycle for more than 60 hours. Second, a novel low-cost biomass route was explored to make shape-designable 3D carbon foam. This carbon foam has the characteristics of ferromagnetism, oil absorption, light weight, and has a three-dimensional carbon network interwoven with cobalt dots, graphene nitride and fibers. The cobalt dots are encapsulated in an external graphitized carbon shell. The core-shell structure of the high-temperature carbonized cobalt-carbon nanocages is compact and connected by Co-N bonds. The Co-N bond further activated the carbon shell and improved the ORR catalytic performance. Electrochemical tests show that the Co-NCF catalyst exhibits excellent ORR performance, with a greater limiting current density (5.74 mA/cm 2 ), a higher onset potential (0.91 V), and a higher half-wave potential (0.83 V ) and long-term stability. Zinc-air batteries used as air cathode catalysts exhibit high power density and discharge capacity. Finally, a novel method of introducing boron was used to prepare the multi-doped metal-carbon catalyst. The study found that the introduction of a small amount of boron can significantly retain the nitrogen content in

　 the catalyst, and the ability of cobalt to bind heteroatoms is improved. The optimized bonding mode between heteroatoms and metallic cobalt further improves the performance of ORR. Electrochemical tests show that the prepared Co-NBSC catalyst has an onset potential of 0.93 V, a half-wave potential of 0.84 V, a current density of 5.58 mA/cm 2 , and excellent stability in alkaline solutions. In addition, the Co-NBSC-based zinc-air battery exhibits a power density of 121.2 mW/cm 2

　and a discharge stability over 30 h. The above-mentioned metal/hybrid carbon electrocatalysts all show excellent performance in zinc-air batteries, which are specifically reflected in higher power density and long-term discharge stability. These provide strategies and ideas for the preparation of new electrocatalysts in the future.

　 Keywords: electrocatalyst; oxygen reduction reaction; oxygen evolution reaction; zinc-air battery

　 目录

　 引言 ............................................................... 1 第一章 绪论 ........................................................ 2 1.1 ORR/OER 反应机理 ............................................ 2 1.1.1 ORR 反应机理 .......................................... 2 1.1.2 OER 反应机理 .......................................... 3 1.2 ORR/OER 电催化剂的研究进展 .................................. 4 1.2.1 ORR 电催化剂的研究进展 ................................ 4 1.2.2 OER 电催化剂的研究进展 ................................ 7 1.3 锌空气电池简介 ............................................. 9 1.3.1 锌空气电池的研究背景 .................................. 9

　1.3.2 锌空气电池的类型 ..................................... 11

　1.3.3 锌空气电池的原理 ..................................... 11 1.3.4 锌空气电池结构的研究 ................................. 13 1.4 本论文选题意义及研究内容 .................................. 15 1.4.1 选题意义 ............................................. 15 1.4.2 研究内容 ............................................. 15 第二章 Co-B-O/NPC 在锌空气电池中的应用研究 ........................ 16 2.1 引言 ....................................................... 16 2.2 实验部分 ................................................... 16 2.2.1 实验试剂及仪器 ....................................... 16 2.2.2 电催化剂的制备 ....................................... 17 2.2.3 结构表征及电化学测试 ................................. 17 2.2.4 锌空气电池和电解水装置的组装 ......................... 18 2.3 结果与讨论 ................................................. 19 2.3.1 结构表征分析 ......................................... 19 2.3.2 电化学测试分析 ....................................... 27 2.3.3 锌空气电池和电解水测试分析 ........................... 32 2.4 本章小结 ................................................... 35 第三章 吸油的碳泡沫在锌空气电池中的应用研究 ....................... 36 3.1 引言 ....................................................... 36

　 3.2 实验部分 ................................................... 36 3.2.1 实验试剂及仪器 ....................................... 36 3.2.2 电催化剂的制备 ....................................... 37 3.2.3 结构表征及电化学测试 ................................. 37 3.2.4 锌空气电池的组装 ..................................... 38 3.3 结果与讨论 ................................................. 38 3.3.1 碳泡沫的合成路线 ..................................... 38 3.3.2 结构表征分析 ......................................... 39 3.3.3 电化学测试分析 ....................................... 48 3.3.4 锌空气电池测试分析 ................................... 51 3.4 本章小结 ................................................... 52 第四章 金属-杂化碳在锌空气电池中的应用研究 ........................ 53 4.1 引言 ....................................................... 53 4.2 实验部分 ................................................... 53 4.2.1 实验试剂及仪器 ....................................... 53 4.2.2 电催化剂的制备 ....................................... 54 4.2.3 结构表征及电化学测试 ................................. 54 4.2.4 锌空气电池的组装 ..................................... 55 4.3 结果与讨论 ................................................. 55 4.3.1 结构表征分析 ......................................... 55 4.3.2 电化学测试分析 ....................................... 62 4.3.3 锌空气电池测试分析 ................................... 66 4.4 本章小结 ................................................... 67 第五章 总结与展望 ................................................. 68 参考文献 .......................................................... 69 攻读硕士期间的研究成果 ............................................ 76 致谢 .............................................................. 77 学位论文独创性声明、学位论文知识产权权属声明 ................