兰州大学机构库 >化学化工学院
有机官能团化-氧空位双增强乙醇电催化氧化
Alternative TitleCombining surface chemical functionalization with introducing reactive oxygen species boosts ethanol electrooxidation
赵金娟
Subtype学士
Thesis Advisor李树文
2023-05-26
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name理学学士
Degree Discipline应用化学
Keyword氧化铈 cerium oxide 氧空位 oxygen vacancy 功能化石墨烯 functionalized graphene palladium 乙醇氧化反应 Ethanol oxidation reaction
Abstract

    开发直接乙醇燃料电池(DEFCs)阳极催化体系的关键是制备高效稳定、成本低廉、绿色环保的电催化剂。基于文献报道,铂基催化剂由于其优越的初始活性得到了广泛的关注与研究。但是铂基催化剂价格昂贵,存在乙醇渗透、CO中毒、长期不稳定等缺点,因此寻找替代催化剂迫在眉睫。由于在碱性环境下钯(Pd)的初始活性优于铂(Pt),且钯(Pd)成本较低、储量较高以及稳定性出色,所以钯(Pd)被认为是替代铂(Pt)的最具有吸引力的电催化剂之一。但钯(Pd)对于乙醇氧化反应(EOR)的固有活性仍未达到直接乙醇燃料电池(DEFCs)阳极催化体系商业化的要求。此外,钯(Pd)的高初始活性不能长期维持,类CO有毒中间体会占据Pd表面活性位点并抑制乙醇氧化反应。在Pd基电催化剂中引入官能团或氧空位是提升电催化反应性能的一种有效策略。

    本文通过简便有效的一步合成方法制备出锚定在D-4-氨基苯丙氨酸(DAP)功能化石墨烯纳米片上的非晶态CeO2-x修饰的Pd基复合材料(Pd-CeO2-x/FGS),并将其用作碱性电解液中乙醇氧化反应(EOR)的电催化剂。相比于Pd/GS,Pd/FGS,Pd-CeO2-x/GS和商业Pd/C,Pd-CeO2-x/FGS表现出较高的电催化活性、快速的的动力学性能和优异的抗中毒能力以及对EOR的稳定耐久性。实验结果表明,Pd-CeO2-x/FGS增强EOR性能的原因是DAP-功能化和CeO2-x修饰。通过DAP-功能化和CeO2-x修饰,Pd-CeO2-x/FGS中引入了大量的官能团(氨基和羧基)和丰富的氧空位。这些官能团有利于小纳米颗粒锚定在基底上并调节Pd的电子密度。氧空位可以提高活性氧物种(OHads)的吸附能力,并加速乙醇氧化反应电位限制步骤的催化动力学。本文为合理设计高效的电氧化反应催化剂提供了新的策略。

Other Abstract

The fundamental challenge in exploiting direct ethanol fuel cells (DEFCs) is the preparation of low price, high active electrocatalysts, which are highly active and durable for the ethanol oxidation reaction (EOR) at the anode. Platinum group metals-based electrocatalysts have been known the governing dual-functional electrocatalysts based on the literature reports. Nevertheless, these catalysts are pricey and commercialize the DMFC less attractive. In addition to the high-cost, there are also ethanol crossover, CO poisoning, long-term instability, and other problems as for Pt-based spurs. Since the initial activity of palladium (Pd) is even better than that of platinum (Pt) in an alkaline environment, palladium (Pd) is considered to be one of the most attractive electrocatalysts to replace platinum (Pt). At the same time, introducing functional groups or oxygen vacancies into Pd-based electrocatalysts is an effective strategy to improve the performance of many electrocatalytic reactions.

The introduction of functional groups or oxygen vacancies into Pd-based electrocatalysts is a powerful strategy for enhancing the electrocatalytic performances for many electrocatalytic reactions. Herein, an amorphous ceria-modified Pd nanocomposite anchored on D-4-amino-phenylalanine (DAP)-functionalized graphene nanosheets (Pd-CeO2x/FGS) was prepared by a facile and effective one-pot synthetic strategy and further used as an electrocatalyst for the ethanol oxidation reaction (EOR) in alkaline electrolytes. The obtained Pd-CeO2x/FGS exhibits relatively high electrocatalytic activity, fast kinetics and excellent anti-poisoning ability as well as robust durability for EOR, outperforming the comparable electrocatalysts as well as commercial Pd/C. The experimental results show that the enhanced EOR properties of Pd-CeO2x/FGS can be attributed to the DAP-functionalization and CeO2x-modification. Adequate functional groups (amino and carboxyl groups) and abundant oxygen vacancies were introduced in Pd-CeO2x/FGS by DAP-functionalization and CeO2x-modifification. The functional groups facilitate the anchoring of small nanoparticles onto the substrate as well as modulate the electron density of Pd. The oxygen vacancies boost the adsorption ability of the reactive oxygen species (OHads) and accelerate the kinetics of the potential-limiting step for EOR. This study proposes a new strategy for the rational design of highly efficient catalysts for the electro-oxidation reaction.

MOST Discipline Catalogue理学 - 化学 - 物理化学(含∶化学物理)
URL查看原文
Language中文
Other Code262010_320190920620
Document Type学位论文
Identifierhttps://ir.lzu.edu.cn/handle/262010/535285
Collection化学化工学院
Affiliation
兰州大学化学化工学院
Recommended Citation
GB/T 7714
赵金娟. 有机官能团化-氧空位双增强乙醇电催化氧化[D]. 兰州. 兰州大学,2023.
Files in This Item:
There are no files associated with this item.
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Altmetrics Score
Google Scholar
Similar articles in Google Scholar
[赵金娟]'s Articles
Baidu academic
Similar articles in Baidu academic
[赵金娟]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[赵金娟]'s Articles
Terms of Use
No data!
Social Bookmark/Share
No comment.
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.