Petroleum and Chemical Industry Key Laboratory of Organic Electrochemical Synthesis, College of Chemical Engineering, and Zhejiang Moganshan Carbon Neutral Innovation Institute, Zhejiang University of Technology, 18 Chaowang Road, Gongshu District, Hangzhou 310032, P. R. China.
School of Advanced Energy, Sun Yat-sen University (Shenzhen), 66 Gongchang Road, Guangming District, Shenzhen 518107, P. R. China.
Acc Chem Res. 2023 Apr 18;56(8):948-958. doi: 10.1021/acs.accounts.2c00809. Epub 2023 Mar 29.
ConspectusOwing to climate change and over-reliance on fossil fuels, the study and development of sustainable energy is of essential importance in the next few decades. In recent years, rapid advances have been witnessed in various power to gas electrocatalysis technologies including oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) for realizing the target of blue planet with carbon neutrality. Nevertheless, practical applications with superior performance and affordable cost are largely limited by the electrode materials because the reactions are regularly driven by precious metals such as platinum (Pt) or iridium (Ir) based catalysts. Therefore, it is of significance to develop novel electrocatalysts with high electroactivity and limited cost for boosting the commercialization of green hydrogen technology.Since nitrogen-doped carbon nanotubes were first reported for enhanced ORR performance in 2009, the exploitation of carbon-based metal-free catalysts (CMFCs) as potential replacements for the precious metal electrocatalysts has become an attractive research field. To date, great progress has been made in developing new dopant strategies for CMFCs; however, the details of the catalytic mechanism and identification of active sites remain unclear, owing to the complexity in controlling the dopants and their homogeneity in carbon-based materials. To tackle this issue, our group has presented a series of works on defects catalyzing electrochemical reactions and proposed a defect catalysis mechanism since 2015. This theory is now widely accepted by the research community and has become a very important area in electrocatalysis worldwide.In this Account, we first present the defect theory for the reasonable design of defective carbon-based materials (DCMs) and subsequently summarize our previous works on the state-of-the-art defect engineering strategies to design DCMs possessing high activity, with the particular emphasis on the conjunction between defect structures and electrochemical performances. We also categorize recent defect modulation approaches on active sites in DCMs as well as showcase the advanced characterization techniques to confirm the types and densities of defects in DCMs. Finally, several perspectives on the challenges and future research opportunities of this exciting field are proposed. Remarkably, rapid advances of DCMs possessing both high electrochemical activities and low cost as a new generation of electrode materials may greatly facilitate the deployment of sustainable energy infrastructures.
概览
由于气候变化和对化石燃料的过度依赖，在未来几十年里，对可持续能源的研究和开发至关重要。近年来，各种电力向气体电催化技术（包括氧还原反应（ORR）、氧析出反应（OER）和析氢反应（HER））取得了快速进展，以实现碳中和的蓝色星球目标。然而，由于这些反应通常由贵金属（如铂（Pt）或铱（Ir）基催化剂）驱动，因此具有优异性能和可承受成本的实际应用在很大程度上受到电极材料的限制。因此，开发具有高电活性和低成本的新型电催化剂对于推动绿色氢气技术的商业化具有重要意义。
自 2009 年首次报道氮掺杂碳纳米管可增强 ORR 性能以来，开发作为贵金属电催化剂潜在替代品的碳基无金属催化剂（CMFCs）已成为一个有吸引力的研究领域。迄今为止，在开发 CMFCs 的新掺杂策略方面已经取得了很大进展；然而，由于在控制掺杂剂及其在碳基材料中的均匀性方面的复杂性，催化机制的细节和活性位点的鉴定仍然不清楚。为了解决这个问题，我们小组自 2015 年以来提出了一系列关于缺陷催化电化学反应的工作，并提出了缺陷催化机制。这一理论现在被研究界广泛接受，并已成为全球电催化领域的一个非常重要的领域。
在本报告中，我们首先介绍了用于合理设计缺陷碳基材料（DCMs）的缺陷理论，随后总结了我们之前关于最先进的缺陷工程策略的工作，以设计具有高活性的 DCMs，特别强调了缺陷结构与电化学性能之间的联系。我们还将 DCMs 中活性位点的最新缺陷调制方法进行了分类，并展示了用于确认 DCMs 中缺陷类型和密度的先进表征技术。最后，提出了对这一令人兴奋的领域的挑战和未来研究机会的几个观点。值得注意的是，作为新一代电极材料的具有高电化学活性和低成本的 DCMs 的快速发展，可能极大地促进可持续能源基础设施的部署。
