随着全球能源需求的迅猛增长,氢能作为一种清洁、高效的能源,其重要性日益凸显。电解水作为制备氢气的理想方法,其效率的提升关键在于优化两个核心反应:析氧反应(OER)和析氢反应(HER)。然而,OER由于其复杂的四电子转移过程和缓慢的动力...随着全球能源需求的迅猛增长,氢能作为一种清洁、高效的能源,其重要性日益凸显。电解水作为制备氢气的理想方法,其效率的提升关键在于优化两个核心反应:析氧反应(OER)和析氢反应(HER)。然而,OER由于其复杂的四电子转移过程和缓慢的动力学特性,成为了限制电解水技术效率提升的关键瓶颈。为了深入研究OER的反应机制,本文借助沸石咪唑酯骨架(ZIF)材料的独特优势,将钴卟啉负载在ZIF材料上,制备了一系列以ZIF材料为基底的OER催化剂。电化学测试表明,钴卟啉@Ni/Co-ZIF复合材料在碱性条件下具有较好的析氧性能,在10 mA cm−2电流密度下的过电位为345 mV,Tafel斜率为95 mV dec−1,且拥有良好的稳定性。With the rapid growth of global energy demand, hydrogen energy as a clean and efficient energy carrier, its importance has become increasingly prominent. Water splitting is an ideal method for hydrogen production, and the key to improve its efficiency is to optimize two core reactions: Oxygen evolution (OER) and hydrogen evolution (HER). However, due to its complex four-electron transfer process and slow kinetic characteristics, OER has become a key bottleneck limiting the efficiency of electrolytic water technology. In order to further study the reaction mechanism of OER, a series of OER catalysts based on zeolite imidazolate framework (ZIF) were prepared by loading cobalt porphyrin on ZIF material with the advantage of ZIF. Electrochemical tests show that cobalt porphyrin@Ni/Co-ZIF material has good oxygen evolution performance with overpotential of 345 mV at 10mA cm−2 current density and Tafel slope of 95 mV dec−1, and good stability under alkaline conditions.展开更多
随着全球能源需求的迅猛增长,氢能作为一种清洁、高效的能源,其重要性日益凸显。电解水作为制备氢气的理想方法,其效率的提升关键在于优化两个核心反应:析氧反应(OER)和析氢反应(HER)。目前,贵金属及其氧化物(如Pt、IrO2和RuO2)作为高...随着全球能源需求的迅猛增长,氢能作为一种清洁、高效的能源,其重要性日益凸显。电解水作为制备氢气的理想方法,其效率的提升关键在于优化两个核心反应:析氧反应(OER)和析氢反应(HER)。目前,贵金属及其氧化物(如Pt、IrO2和RuO2)作为高活性电催化剂被广泛应用,以加快水电解过程的转化效率。然而,贵金属材料具有稀缺性和不稳定性,这严重阻碍了其在实践中的大规模应用。在过去的几年里,金属有机框架材料(MOF)由于其独特的物理化学性质已经被证明是设计高效和经济的电催化剂的理想平台。本文首先讨论了析氢反应和析氧反应的基本催化机理,接着介绍了镍基MOF电催化剂用于HER和OER的最新研究进展,并对当前面临的挑战和未来的发展进行了总结。With the rapid growth of global energy demand, hydrogen energy as a clean and efficient energy carrier, its importance has become increasingly prominent. Electrolysis of water is an ideal method for hydrogen production, and the key to improve its efficiency is to optimize two core reactions: oxygen evolution (OER) and hydrogen evolution (HER). At present, noble metals and their oxides (e.g., Pt, IrO2, and RuO2) are widely used as high active electrocatalysts for accelerating the conversion efficiency of the water electrolysis process. However, the scarcity and instability seriously impede their large-scale application in practice. In the past years, metal-organic frameworks (MOFs) have proven to be an ideal platform for designing efficient and cost-effective electrodes due to their unique physicochemical properties. In this review, the fundamental catalytic mechanisms of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in acidic media are discussed first. Then, the recent research advances of Ni-MOF-based electrocatalysts for HER and OER in acidic electrolytes, along with current challenges and future opportunities, are provided.展开更多
铬(III)具有[Ar] 3d3的电子构型,属于d3离子类别。在八面体配位环境中,它简并的t2g轨道上只能容纳三个电子,这会使Jahn-Teller效应减弱。因此,该离子显示出相对较弱的磁各向异性,这也导致了关于利用铬(III)作为中心离子的单分子磁体(SMM...铬(III)具有[Ar] 3d3的电子构型,属于d3离子类别。在八面体配位环境中,它简并的t2g轨道上只能容纳三个电子,这会使Jahn-Teller效应减弱。因此,该离子显示出相对较弱的磁各向异性,这也导致了关于利用铬(III)作为中心离子的单分子磁体(SMM)的研究报告十分缺乏。因此,本文通过对近年来典型的铬–稀土单分子磁体进行综述,以期为3d-4f单分子磁体的发展奠定一定的基础。Chromium(III) has an electronic configuration of [Ar] 3d3 and belongs to the d3 ion category. In an octahedral coordination environment, its degenerate t2g orbital can only accommodate three electrons, which weakens the Jahn Teller effect. Therefore, the ion exhibits relatively weak magnetic anisotropy, which also leads to a lack of research reports on single molecule magnets (SMMs) using chromium(III) as the central ion. This article reviews typical chromium lanthanide based single molecule magnets in recent years, in order to lay a certain foundation for the development of 3d-4f single molecule magnets.展开更多
在3d-4f类型中的单分子磁体里,铜通常以二价的形式存在,并且它的特征电子构型为3d9,因此被认为是顺磁中心。在八面体配位环境中,CuII的d层轨道分裂成了t2g6eg3,这就导致了CuII中会出现Jahn-Teller效应。结合这些特性,CuII会表现出中等...在3d-4f类型中的单分子磁体里,铜通常以二价的形式存在,并且它的特征电子构型为3d9,因此被认为是顺磁中心。在八面体配位环境中,CuII的d层轨道分裂成了t2g6eg3,这就导致了CuII中会出现Jahn-Teller效应。结合这些特性,CuII会表现出中等的磁各向异性,因此通常被认为是各向同性离子。然而,由于其灵活的配位性,以及它会与4f金属形成强铁磁耦合的能力,Cu-Ln SMMs仍然是研究的焦点。In 3d-4f SMMs, copper is typically present in the CuⅡ form, characterized by 3d9 electron configuration, and is thus commonly regarded as paramagnetic center. In octahedral coordination environment, the d orbitals of CuⅡ split into t2g6eg3, leading to the occurrence of the Jahn-Teller effect in CuⅡ. Combining these characteristics, CuⅡ exhibits moderate magnetic anisotropy, and thus is often regarded as isotropic ion. However, due to its flexible coordination, along with its ability to form strong ferromagnetic couplings with 4f metals, Cu-Ln SMMs have remained the focal point of research.展开更多
文摘随着全球能源需求的迅猛增长,氢能作为一种清洁、高效的能源,其重要性日益凸显。电解水作为制备氢气的理想方法,其效率的提升关键在于优化两个核心反应:析氧反应(OER)和析氢反应(HER)。然而,OER由于其复杂的四电子转移过程和缓慢的动力学特性,成为了限制电解水技术效率提升的关键瓶颈。为了深入研究OER的反应机制,本文借助沸石咪唑酯骨架(ZIF)材料的独特优势,将钴卟啉负载在ZIF材料上,制备了一系列以ZIF材料为基底的OER催化剂。电化学测试表明,钴卟啉@Ni/Co-ZIF复合材料在碱性条件下具有较好的析氧性能,在10 mA cm−2电流密度下的过电位为345 mV,Tafel斜率为95 mV dec−1,且拥有良好的稳定性。With the rapid growth of global energy demand, hydrogen energy as a clean and efficient energy carrier, its importance has become increasingly prominent. Water splitting is an ideal method for hydrogen production, and the key to improve its efficiency is to optimize two core reactions: Oxygen evolution (OER) and hydrogen evolution (HER). However, due to its complex four-electron transfer process and slow kinetic characteristics, OER has become a key bottleneck limiting the efficiency of electrolytic water technology. In order to further study the reaction mechanism of OER, a series of OER catalysts based on zeolite imidazolate framework (ZIF) were prepared by loading cobalt porphyrin on ZIF material with the advantage of ZIF. Electrochemical tests show that cobalt porphyrin@Ni/Co-ZIF material has good oxygen evolution performance with overpotential of 345 mV at 10mA cm−2 current density and Tafel slope of 95 mV dec−1, and good stability under alkaline conditions.
文摘随着全球能源需求的迅猛增长,氢能作为一种清洁、高效的能源,其重要性日益凸显。电解水作为制备氢气的理想方法,其效率的提升关键在于优化两个核心反应:析氧反应(OER)和析氢反应(HER)。目前,贵金属及其氧化物(如Pt、IrO2和RuO2)作为高活性电催化剂被广泛应用,以加快水电解过程的转化效率。然而,贵金属材料具有稀缺性和不稳定性,这严重阻碍了其在实践中的大规模应用。在过去的几年里,金属有机框架材料(MOF)由于其独特的物理化学性质已经被证明是设计高效和经济的电催化剂的理想平台。本文首先讨论了析氢反应和析氧反应的基本催化机理,接着介绍了镍基MOF电催化剂用于HER和OER的最新研究进展,并对当前面临的挑战和未来的发展进行了总结。With the rapid growth of global energy demand, hydrogen energy as a clean and efficient energy carrier, its importance has become increasingly prominent. Electrolysis of water is an ideal method for hydrogen production, and the key to improve its efficiency is to optimize two core reactions: oxygen evolution (OER) and hydrogen evolution (HER). At present, noble metals and their oxides (e.g., Pt, IrO2, and RuO2) are widely used as high active electrocatalysts for accelerating the conversion efficiency of the water electrolysis process. However, the scarcity and instability seriously impede their large-scale application in practice. In the past years, metal-organic frameworks (MOFs) have proven to be an ideal platform for designing efficient and cost-effective electrodes due to their unique physicochemical properties. In this review, the fundamental catalytic mechanisms of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in acidic media are discussed first. Then, the recent research advances of Ni-MOF-based electrocatalysts for HER and OER in acidic electrolytes, along with current challenges and future opportunities, are provided.
文摘铬(III)具有[Ar] 3d3的电子构型,属于d3离子类别。在八面体配位环境中,它简并的t2g轨道上只能容纳三个电子,这会使Jahn-Teller效应减弱。因此,该离子显示出相对较弱的磁各向异性,这也导致了关于利用铬(III)作为中心离子的单分子磁体(SMM)的研究报告十分缺乏。因此,本文通过对近年来典型的铬–稀土单分子磁体进行综述,以期为3d-4f单分子磁体的发展奠定一定的基础。Chromium(III) has an electronic configuration of [Ar] 3d3 and belongs to the d3 ion category. In an octahedral coordination environment, its degenerate t2g orbital can only accommodate three electrons, which weakens the Jahn Teller effect. Therefore, the ion exhibits relatively weak magnetic anisotropy, which also leads to a lack of research reports on single molecule magnets (SMMs) using chromium(III) as the central ion. This article reviews typical chromium lanthanide based single molecule magnets in recent years, in order to lay a certain foundation for the development of 3d-4f single molecule magnets.
文摘在3d-4f类型中的单分子磁体里,铜通常以二价的形式存在,并且它的特征电子构型为3d9,因此被认为是顺磁中心。在八面体配位环境中,CuII的d层轨道分裂成了t2g6eg3,这就导致了CuII中会出现Jahn-Teller效应。结合这些特性,CuII会表现出中等的磁各向异性,因此通常被认为是各向同性离子。然而,由于其灵活的配位性,以及它会与4f金属形成强铁磁耦合的能力,Cu-Ln SMMs仍然是研究的焦点。In 3d-4f SMMs, copper is typically present in the CuⅡ form, characterized by 3d9 electron configuration, and is thus commonly regarded as paramagnetic center. In octahedral coordination environment, the d orbitals of CuⅡ split into t2g6eg3, leading to the occurrence of the Jahn-Teller effect in CuⅡ. Combining these characteristics, CuⅡ exhibits moderate magnetic anisotropy, and thus is often regarded as isotropic ion. However, due to its flexible coordination, along with its ability to form strong ferromagnetic couplings with 4f metals, Cu-Ln SMMs have remained the focal point of research.
