固体电解质电解池一氧化碳电催化还原反应研究

以α-Zr(HPO4)H2O为质子固体电解质设计电解池, 于常温常压实现了CO电催化加氢还原反应, 反应产物与电极材料、 电流密度密切相关. Cu/ZrP电极表面反应主要产物是甲醛, 电流密度100 mA/cm2时, 甲醛的Faradic效率达到29.0 %, Fe/ZrP电极表面反应主要产物是乙烯, 电流密度100 mA/cm2-时, 乙烯的Faradic效率达到15.0%.     

用于二氧化碳电催化还原的电解器研究进展

The electrocatalytic CO₂ reduction reaction (CO₂RR) driven by renewable energy is an efficient approach to achieve the conversion and utilization of CO₂. In this context, CO₂RR has become an emerging research focus in the field of electrocatalysis over the past decade. While a large number of nanostructured catalysts have been developed to accelerate CO₂RR, the tradeoff between activity and selectivity usually renders the overall electrocatalytic performance very poor. Beyond catalyst design, rationally designing electrolyzers is also of substantial importance for improving the CO₂RR performance and achieving its scale-up for practical applications. To a large extent, the electrolyzer configuration determines the local reaction environment near an electrode by affecting the process conditions, thereby resulting in remarkably different electrocatalytic performances. To be techno-economically viable, the performance of CO₂ electrolyzers is expected to be at least comparable to that of the current state-of-the-art proton exchange membrane (PEM) water electrolyzers, with regard to their activity, selectivity, and stability. Researchers have made great progress in the development of CO₂ electrolyzers over the past few years, but they are also facing many issues and challenges. This review aims to provide an in-depth analysis of the research progress and status of current CO₂ electrolyzers including H-cell, flow-cell, and membrane electrode assembly cell (MEA-cell) electrolyzers. Herein, operation at industrial current densities (> 200 mA∙cm⁻²) is set as a basis when these electrolyzers are discussed and compared in terms of the four main figures of merit (current density, Faradic efficiency, energy efficiency and stability) that describe the CO₂RR performance of an electrolyzer. The advantages and drawbacks of each electrolyzer are discussed and highlighted with emphasis on the key achievements reported to date. Compared to conventional H-cell electrolyzers that work well in mechanistic studies, the newly developed electrolyzers using gas diffusion electrodes, both flow-cell and MEA-cell electrolyzers, are able to break the limitation of CO₂ solubility in water and acquire industrial current densities. Although flow-cell electrolyzers have achieved current densities exceeding 1 A∙cm⁻², they suffer from low energy efficiencies because of the significant iR drop and poor stability owing to the use of alkaline electrolytes. These issues can be overcome in the case of zero-gap MEA-cell electrolyzers with ion exchange membranes being as solid electrolytes. The anion exchange membrane (AEM)-based CO₂ electrolyzers are at the center of the current research, as they demonstrate promising activity and selectivity toward specific CO₂RR products and exhibit excellent stability for over thousands of hours in few cases. Meanwhile, the crossover of CO₂ and liquid products from the cathode to the anode through the membrane tends to lower the utilization efficiency of the CO₂ supplied to the AEM electrolyzers. MEA-cell electrolyzers using cation exchange membranes and bipolar membranes have also been explored; however, neither of them have shown satisfactory CO₂RR performance. The development of new polymer electrolyte membranes and ionomers would help address these problems. While issues and challenges still exist, MEA-cell electrolyzers hold the greatest promise for practical applications. As concluding remarks, research strategies and opportunities for the future have been proposed to accelerate the development of CO₂RR technology for practical applications and to deepen the mechanistic understanding behind improved performance. This review provides new insights into rational electrolyzer design and guidelines for researchers in this field.     

酸性条件下二氧化碳高效电还原策略（英文）

二氧化碳电还原技术可以将可再生电能与温室气体二氧化碳转化为高价值燃料和化学品.选择性、能量转化效率、碳利用效率和可持续性是评价二氧化碳电还原技术是否具有工业应用前景的主要指标.在碱性或中性电解液中进行二氧化碳电还原,由于部分二氧化碳在阴极转化为碳酸盐,导致碳利用效率降低.碱性电解液和中性电解液还分别存在电解液再生过程耗能巨大和溶液电阻较高等问题.这些因素导致使用碱性和中性电解液的二氧化碳电还原技术能量转化效率低下.最近,酸性条件下二氧化碳电还原技术有望提高碳利用效率和能量利用效率,成为研究热点.然而,在酸性条件下提升二氧化碳还原选择性具有挑战.前期研究已发展了多种策略以抑制酸性条件下的氢离子还原反应并促进二氧化碳还原反应,但研究者对于酸性条件下的阳离子效应以及局域pH效应等基础科学问题认识尚不一致.此外,气体扩散电极内的碳酸氢盐盐析问题仍限制着酸性条件下二氧化碳还原电解系统的可持续性.因此,亟需对促进酸性条件下二氧化碳电还原的不同策略及可能机制进行总结,并探讨进一步提升电解系统可持续性的潜在路径.本文首先概述了酸性条件下二氧化碳电还原技术的提出及发展历程,对比了碱性、中性和酸性电解液中...     

咪唑鎓盐基材料电催化二氧化碳还原研究进展（英文）

随着化石能源的使用日益增加,大气中CO₂的浓度不断上升,给环境带来了挑战。通过催化将CO₂转化为高附加值化学品为解决这些问题提供了一个机会,并为燃料合成开辟了一条新的途径,最终有助于减少CO₂排放并实现碳中和。在众多的方法中,利用可再生清洁能源进行CO₂电还原反应(CO₂RR)以其反应条件温和、反应进度可控、环境友好以及可以产生大量的附加值产品而受到重视。在此背景下,咪唑鎓基材料及其衍生物已成为CO₂RR的有潜力的候选材料。这些材料对CO₂有很强的亲和力,并且在CO₂RR系统中作为电解质和电催化剂都有应用。所以它们的主要优点之一是能够在催化体系中富集CO₂,有效地抑制析氢副反应(HER),并提高CO₂RR产物的选择性。了解电催化条件下咪唑鎓基离子液体(Im-ILs)与CO₂分子之间的相互作用机制对于从分子角度深入了解为什么添加Im-ILs可以改善C...     

氮硫共掺杂高比表面中空碳球的制备及其在电催化二氧化碳还原中的应用（英文）

化石燃料是现代能源体系的重要支柱,其大量使用导致大气中CO₂浓度不断增加,加剧了全球变暖和环境恶化.因此,各国研究人员开发了大量技术手段以捕获和重新再利用CO₂这一丰富的碳资源.其中, CO₂电催化还原(CO₂RR)技术在减少CO₂排放和将其转化为有用化学品等方面极具潜力.但是, CO₂RR具有反应能垒高和动力学过程缓慢等特点,进而限制其转化效率,故使用传统的贵金属材料(Ag, Au, Cu及Pd等)作为CO₂RR高效的催化剂.然而,贵金属材料的大规模应用受限于它们成本高昂、稳定性差及环境毒性等缺点.在各类可替代贵金属催化剂中,碳材料因其廉价丰富、结构可调和导电性高的特点在CO₂RR应用上展现出诱人的前景,因此,探索合适的碳基催化剂在高效催化二氧化碳领域具有重要的研究价值和意义.本文通过简单有效的方法制备了一种氮硫共掺杂的高比表面的碳基催化剂(SZ-HCN)用于CO₂RR.首先利用表面活性剂...     

多金属氧酸盐材料在二氧化碳电催化还原领域中的研究进展（英文）

随着工业发展和全球人口的持续增长,人类对化石燃料的消耗日益增加,从而导致大气中二氧化碳含量的显著增加以及与之相伴的一系列环境问题.电化学还原二氧化碳制备高附加值的燃料和化学品具有稳定的效率和较高的经济可行性等特点,目前已成为一种有前景的策略来缓解当前全球面临的能源短缺和气候变暖问题.然而,电催化二氧化碳还原过程存在反应能垒高和复杂的多电子/质子耦合过程等不足,因此,合理有效的电催化剂设计成为该领域的关键问题.近年,理解和明确电化学二氧化碳还原反应过程的活性起源、选择性调控机制和催化反应机理已成为高效电催化剂设计过程中的重要指导原则.作为一类独特的纳米尺度的金属氧簇,多金属氧酸盐(多酸)已成为二氧化碳还原领域的热点材料.尤其是,多酸明确的结构、优越的电子/质子存储转移能力和二氧化碳吸附活化能力有助于探究二氧化碳还原反应过程中的活性起源和构效机制.因此,利用多酸阐明电化学二氧化碳还原反应中的这些关键问题对于开发高效、可实用化的电催化剂意义重大.本文综述了近年多酸在电催化二氧化碳还原反应中取得的进展,重点介绍了多酸阴离子均相分子催化剂、多酸基无机-有机杂化材料催化剂、多酸电解质溶液、多酸-纳...     

二氧化碳电还原催化剂调控策略与结构效应（英文）

随着化石燃料的消耗,全球碳排放与日俱增,由此引发的温室效应对全球气候变化带来巨大的挑战,温室气体CO₂的减排与利用迫在眉睫.利用太阳能、风能等可再生资源生产的电能能够将CO₂还原为一系列有附加值的化学品如醇、酸等有机小分子,人为构造碳循环网络,实现碳中和.本文综述了电催化CO₂还原反应(CO₂RR)催化剂的调控策略和结构效应.从本征结构和外部结构的角度阐述了催化剂活性位点的调控策略.同时讨论了CO₂RR催化剂的结构效应,如串联催化、协同效应和限域催化.关于催化剂的调控策略,从催化剂的本征结构和外部结构两方面总结了近年CO₂RR催化剂的研究进展.特定的元素或化合物可以表现出不同的晶体结构,造成局部电子结构差异.而局部电子结构与催化剂的催化性能密切相关,调整晶体结构成为本征结构调控的核心问题,因此本文探讨了如何通过电化学方法和纳米晶体合成调节催化剂的本征结构.与本征结构不同,催化剂的外部结构与活性位点的微环境有关.催化剂的外部结构调节主要基于各种电子结构的协同...     

一体化电极电催化二氧化碳还原研究进展

电催化二氧化碳还原反应(E-CO₂RR)可在温和条件下将CO₂转化成高附加值燃料或化学品,近年来受到广泛关注,其在实际反应中涉及到气体扩散和多电子转移等复杂过程,构筑高效、稳定的催化电极是其发展的核心之一。然而,传统涂敷电极制备时,需要将催化剂与粘结剂混合涂覆于集流体表面,此过程会造成活性位点包埋和传质过程受限,致使催化剂活性位利用率下降,同时在反应过程中电极表面容易粉化,造成稳定性下降,难以重复利用。因此,如何调控电极反应界面,提升催化剂活性位的利用率仍面临挑战。将催化剂原位生长于集流体上得到的一体化电极可直接应用于电催化反应,不仅有利于提升活性位利用率以及电荷传输能力,还能有效调控三相界面处的微观反应环境(如pH、反应物及反应中间体的浓度等),从而实现电催化性能强化。本文综述了一体化电极用于E-CO₂RR的最新进展,分析了结构和表界面调控对E-CO₂RR性能的影响规律,并对该领域仍然存在的挑战和未来一体化E-CO₂RR电极的发展进行了评述与展望。     

二氧化碳电还原为甲烷的研究进展（英文）

通过电化学手段将CO₂转化为高附加值的化学品和燃料是缓解能源短缺与环境危机的一种重要方法.在电还原过程制备的所有含碳产物中, CH₄拥有最高的热值(56 k J/g),是最重要的化学键能储备载体之一.本文以先前报道的反应机理为出发点,从催化剂设计策略的角度总结了CO₂电还原制CH₄的最新研究进展.催化剂设计策略包括亚纳米催化位点构筑、界面调控、原位结构演变以及串联催化剂构筑.基于已有的理论预测与实验结果,获取对制备CH₄反应机理更深层次的理解,进而反馈指导高效催化剂的设计合成.亚纳米催化位点构筑可有效抑制反应过程中的C-C偶联,进而提升CO₂电还原制CH₄的催化性能.界面调控利用活性相与衬底间的协同作用,可优化含氧中间体的结合能,确保反应按预期路径进行.原位结构演变可构建热力学稳定的活性相,进而增强CO₂电还原制CH₄的催化活性.串联催化通过构筑多种活性位点将总包反应分为不同阶段,可有效打破...     

铜–锑双金属合金高效电催化还原二氧化碳制乙烯（英文）

随着全球工业化进程的快速发展,日益增多的人类活动不仅加速化石燃料的消耗,还会导致温室气体二氧化碳(CO₂)的大量排放.同时,CO₂也是廉价、无毒无害、储量丰富的C₁资源,将其转化为有价值的化学品具有碳资源合理利用和环境保护的双重意义.近年来,采用电化学方法温和条件下还原CO₂为重要化学品和燃料引起广泛关注.其中,探索廉价电催化剂,高效催化还原CO₂为C₂产物仍是一个具有挑战性的课题.铜基催化剂由于自身低成本和可还原CO₂为多种碳氢产物的优点而备受关注.然而,铜基电催化材料具有选择性差、失活严重和效率低等缺点,并且在电催化还原CO₂过程中需要较高的过电位,反应过程中会受到氢气析出副反应的影响.为了得到一种化学性质稳定、高电流密度和高选择性等优点的材料在电催化CO₂还原中得到了广泛的研究.然而,单纯的铜催化剂对CO₂分子的活化以及反应中间体的吸附能力较低,导致了铜基材料催化...     

海胆针状金纳米颗粒用于电催化二氧化碳还原

采用不加表面活性剂的种子介导生长策略合成了具有针状结构的金纳米颗粒, 其针尖处的尖端电场效应能有效富集电解质阳离子并提高二氧化碳局部浓度, 从而提高催化剂的电流密度和一氧化碳选择性, 在 -0.6 V(vs. RHE)时的法拉第效率可以达到96%. 电化学性能测试结果表明, 其高选择性不仅来源于丰富的表面缺陷, 更主要源于其独特的针状结构所带来的尖端电场效应.     

Electrolyte Effects on the Electrochemical Reduction of CO2

The electrochemical reduction of CO₂ to fuels or commodity chemicals is a reaction of high interest for closing the anthropogenic carbon cycle. The role of the electrolyte is of particular interest, as the interplay between the electrocatalytic surface and the electrolyte plays an important role in determining the outcome of the CO₂ reduction reaction. Therefore, insights on electrolyte effects on the electrochemical reduction of CO₂ are pivotal in designing electrochemical devices that are able to efficiently and selectively convert CO₂ into valuable products. Here, we provide an overview of recently obtained insights on electrolyte effects and we discuss how these insights can be used as design parameters for the construction of new electrocatalytic systems.     

太阳能驱动Ni-N掺杂多孔碳高效电催化还原CO2为CO

利用可再生能源将二氧化碳(CO2)电催化还原为有价值的化学品和燃料,不仅可缓解温室效应,而且可实现碳资源的循环利用。以蛋白胨与盐形成的凝胶为原料,经高温热解后制备了用于电还原CO2的Ni-N掺杂碳多孔催化剂。该催化剂表现出优异的电催化还原CO2为CO的性能,在电压为-0.66 V(vs.RHE)下,CO的法拉第效率为92.0%,过电位为550 mV,还原电流密度为2.5 mA·cm-2。该催化剂优异的CO2的电催化活性归因于其存在的Ni-N活性位点和高度多孔的结构。此外,利用太阳能电池产生的电能,该催化剂可持续进行CO2电催化还原为CO,为CO2的资源化利用提供了有价值的参考。     

金团簇电催化二氧化碳还原反应的研究进展

二氧化碳电还原反应(CO₂RR)在改善能源利用方式、 实现可持续碳循环以及生产高附加值液体燃料和化学品等方面具有广阔的应用前景, 近年来受到广泛关注. 有机配体保护的金团簇具有确定的晶体结构, 其不同的尺寸、 配体及组成可以有效调控氧化还原电位, 作为一种独特的模型催化剂, 为探索原子水平的CO₂RR反应机理提供了新机遇. 本文综合评述了纯金团簇和异金属原子掺杂的金团簇催化CO₂RR的研究进展, 包括金团簇的电荷、 尺寸、 配体以及掺杂对CO₂RR性能的影响, 重点讨论了CO₂RR的反应机理, 总结了金团簇在CO₂RR中所面临的挑战, 并展望了金团簇在CO₂RR中未来的研究方向和发展前景.     

Thiol‐Assisted Synthesis of Carbon‐Supported Metal Nanoparticles for Efficient Electrocatalytic CO2 Reduction

The typical preparation route of carbon‐supported metallic catalyst is complex and uneconomical. Herein, we reported a thiol‐assisted one‐pot method by using 3‐mercaptopropionic acid (MPA) to synthesize carbon‐supported metal nanoparticles catalysts for efficient electrocatalytic reduction of carbon dioxide (CO₂RR). We found that the synthesized Au?MPA/C catalyst achieves a maximum CO faradaic efficiency (FE) of 96.2% with its partial current density of ?11.4 mA/cm², which is much higher than that over Au foil or MPA‐free carbon‐supported Au (Au/C). The performance improvement in CO₂RR over the catalyst is probably derived from the good dispersion of Au nanoparticles and the surface modification of the catalyst caused by the specific interaction between Au nanoparticles and MPA. This thiol‐assisted method can be also extended to synthesize Ag?MPA/C with enhanced CO₂RR performance.     

Nanostructures for Electrocatalytic CO2 Reduction

One of the most effective ways to cope with the problems of global warming and the energy shortage crisis is to develop renewable and clean energy sources. To achieve a carbon-neutral energy cycle, advanced carbon sequestration technologies are urgently needed, but because CO₂ is a thermodynamically stable molecule with the highest carbon valence state of +4, this process faces many challenges. In recent years, electrochemical CO₂ reduction has become a promising approach to fix and convert CO₂ into high-value-added fuels and chemical feedstock. However, the large-scale commercial use of electrochemical CO₂ reduction systems is hindered by poor electrocatalyst activity, large overpotential, low energy conversion efficiency, and product selectivity in reducing CO₂. Therefore, there is an urgent need to rationally design highly efficient, stable, and scalable electrocatalysts to alleviate these problems. This minireview also aims to classify heterogeneous nanostructured electrocatalysts for the CO₂ reduction reaction (CDRR).     

Membrane Electrode Assembly for Electrocatalytic CO2 Reduction: Principle and Application

Electrocatalytic CO₂ reduction reaction (CO₂RR) in membrane electrode assembly (MEA) systems is a promising technology. Gaseous CO₂ can be directly transported to the cathode catalyst layer, leading to enhanced reaction rate. Meanwhile, there is no liquid electrolyte between the cathode and the anode, which can help to improve the energy efficiency of the whole system. The remarkable progress achieved recently points out the way to realize industrially relevant performance. In this review, we focus on the principles in MEA for CO₂RR, focusing on gas diffusion electrodes and ion exchange membranes. Furthermore, anode processes beyond the oxidation of water are considered. Besides, the voltage distribution is scrutinized to identify the specific losses related to the individual components. We also summarize the progress on the generation of different reduced products together with the corresponding catalysts. Finally, the challenges and opportunities are highlighted for future research.     

电解液调控CO2电催化还原性能微观机制的研究进展

二氧化碳(CO₂)排放导致了严重的温室效应, 但作为重要的碳资源, CO₂电催化还原合成化学品因反应条件温和、 反应产物可调及可有效利用分布式电能等优势而备受关注. 在该反应体系中, 电解液作为反应介质, 可提供质子和反应微环境, 影响分子/离子传输. 因此, 构建新型电解液体系对于提高CO₂电催化还原产物的选择性和电流密度起到重要作用. 本文综合评述了CO₂电催化还原过程中电解液的作用和研究现状, 重点总结了水系电解液中阴阳离子(碱金属阳离子、 卤素离子等)和离子液体电解液对CO₂溶解度、 界面双电层结构(pH值、 电场效应)和中间体稳定性等的影响机制, 揭示了其调控对反应产物的选择性、 电流密度等的影响规律. 最后, 对电解液调控CO₂电催化还原性能的研究进行了展望.     

Metal-Based Aerogels Catalysts for Electrocatalytic CO2 Reduction

General strategies for metal aerogel synthesis, including single-metal, transition-metal doped, multi-metal-doped, and nano-metal-doped carbon aerogel are described. In addition, the latest applications of several of the above-mentioned metal aerogels in electrocatalytic CO₂ reduction are discussed. Finally, considering the possibility of future applications of electrocatalytic CO₂ reduction technology, a vision for industrialization and directions that can be optimized are proposed.