共查询到20条相似文献,搜索用时 0 毫秒
1.
多组分体系中的协同作用为设计高效的二氧化碳还原电催化剂提供了新的思路. 本工作通过双模板法和化学还原法精心设计制备了大孔/介孔镍氮掺杂碳(Ni-N-OMMC)负载银纳米颗粒复合材料(Ag/Ni-N-OMMC), 用于高效电催化还原CO2为CO. 此复合材料表现出良好的电催化活性, 在CO2饱和的0.1 mol•L–1 KHCO3电解液中, 电位为–1.0 V (相对于可逆氢电极, RHE)时CO的电流密度(JCO)高达33.29 mA•cm–2. 并具有较宽的工作电压范围, 在–0.7~–1.0 V (vs. RHE)下, CO的法拉第效率超过90%. 其优异的电催化性能可能归因于Ag纳米颗粒与具有丰富Ni-N x活性位点的Ni-N-OMMC载体之间的协同效应, 以及三维互联有序大孔/介孔结构提供的高比表面积和高效的质量/电荷传输. 相似文献
2.
3.
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。 相似文献
4.
Tuning Gold Nanoparticles with Chelating Ligands for Highly Efficient Electrocatalytic CO2 Reduction
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2018,130(39):12857-12861
Capped chelating organic molecules are presented as a design principle for tuning heterogeneous nanoparticles for electrochemical catalysis. Gold nanoparticles (AuNPs) functionalized with a chelating tetradentate porphyrin ligand show a 110‐fold enhancement compared to the oleylamine‐coated AuNP in current density for electrochemical reduction of CO2 to CO in water at an overpotential of 340 mV with Faradaic efficiencies (FEs) of 93 %. These catalysts also show excellent stability without deactivation (<5 % productivity loss) within 72 hours of electrolysis. DFT calculation results further confirm the chelation effect in stabilizing molecule/NP interface and tailoring catalytic activity. This general approach is thus anticipated to be complementary to current NP catalyst design approaches. 相似文献
5.
采用温度控制的浸渍-热解法, 合成了以碳纳米管为载体的一系列铜单原子催化剂. 扩展X射线吸收精细结构(EXAFS)分析表明, 催化剂中的单原子铜位点分别由吡啶氮和吡咯氮配位. 电催化性能测试表明, 所制备催化剂可用于电催化二氧化碳生成一氧化碳, 由吡啶氮配位的铜单原子催化剂的反应选择性较差, 而由吡咯氮配位的铜单原子催化剂则具有更强的活性, CO法拉第效率在-0.70 V(vs. RHE)时可达到96.3%; 吡咯氮配位的铜单原子中心对于析氢反应具有更好的抑制效果. 相似文献
6.
7.
Guangtao Wang Xiang Li Xiaohan Yang Dr. Li-Xia Liu Yanming Cai Yajun Wu Shengyan Wang Huan Li Prof. Yuanzhen Zhou Prof. Yuanyuan Wang Prof. Yang Zhou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(64):e202201834
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. 相似文献
8.
Lin Jia Hui Yang Jun Deng Junmei Chen Yuan Zhou Pan Ding Leigang Li Na Han Yanguang Li 《中国化学》2019,37(5):497-500
Electrocatalytic carbon dioxide reduction holds great promise for reducing the atmospheric CO2 level and alleviating the energy crisis. High‐performance electrocatalysts are often required in order to lower the high overpotential and expedite the sluggish reaction kinetics of CO2 electroreduction. Copper is a promising candidate metal. However, it usually suffers from the issues of poor stability and low product selectivity. In this work, bimetallic Cu‐Bi is obtained by reducing the microspherical copper bismuthate (CuBi2O4) for selectively catalyzing the CO2 reduction to formate (HCOO–). The bimetallic Cu‐Bi electrocatalyst exhibits high activity and selectivity with the Faradic efficiency over 90% in a wide potential window. A maximum Faradaic efficiency of ~95% is obtained at –0.93 V versus reversible hydrogen electrode. Furthermore, the catalyst shows high stability over 6 h with Faradaic efficiency of ~95%. This study provides an important clue in designing new functional materials for CO2 electroreduction with high activity and selectivity. 相似文献
9.
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. 相似文献
10.
炭载Ru-Fe催化剂对直接甲酸燃料电池中氧还原的电催化性能研究 总被引:3,自引:2,他引:1
研究了作为直接甲酸燃料电池(DFAFC)阴极催化剂的炭载Ru(Ru/C)和炭载Ru-Fe(Ru-Fe/C)催化剂对氧还原的电催化性能和抗甲酸能力。发现Ru-Fe/C催化剂对氧还原的电催化活性要远好于Ru/C催化剂。进一步的研究发现,只有与Ru形成合金的Fe才能提高Ru/C催化剂对氧还原的电催化活性。另外,Ru-Fe/C催化剂对甲酸氧化没有电催化活性。因此,Ru-Fe/C催化剂也有很好的抗甲酸能力。所以,Ru-Fe/C催化剂适合作为DFAFC的阴极催化剂。 相似文献
11.
Qingqing Wang Yao Zhang Dr. Huijuan Lin Prof. Jixin Zhu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(62):14026-14035
Considerable attention has been paid to the utilization of CO2, an abundant carbon source in nature. In this regard, porous catalysts have been eagerly explored with excellent performance for photo-/electrocatalytic reduction of CO2 to high valued products. Metal–organic frameworks (MOFs), featuring large surface area, high porosity, tunable composition and unique structural characteristics, have been widely exploited in catalytic CO2 reduction. This Minireview first reports the current progress of MOFs in CO2 reduction. Then, a specific interest is focused on MOFs in photo-/electrocatalytic reduction of CO2 by modifying their metal centers, organic linkers, and pores. Finally, the future directions of study are also highlighted to satisfy the requirement of practical applications. 相似文献
12.
Huinian Zhang Jing Li Shibo Xi Yonghua Du Xiao Hai Junying Wang Haomin Xu Gang Wu Jia Zhang Jiong Lu Junzhong Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(42):15013-15018
Electrochemical conversion of CO2 into valued products is one of the most important issues but remains a great challenge in chemistry. Herein, we report a novel synthetic approach involving prolonged thermal pyrolysis of hemin and melamine molecules on graphene for the fabrication of a robust and efficient single‐iron‐atom electrocatalyst for electrochemical CO2 reduction. The single‐atom catalyst exhibits high Faradaic efficiency (ca. 97.0 %) for CO production at a low overpotential of 0.35 V, outperforming all Fe‐N‐C‐based catalysts. The remarkable performance for CO2‐to‐CO conversion can be attributed to the presence of highly efficient singly dispersed FeN5 active sites supported on N‐doped graphene with an additional axial ligand coordinated to FeN4. DFT calculations revealed that the axial pyrrolic nitrogen ligand of the FeN5 site further depletes the electron density of Fe 3d orbitals and thus reduces the Fe–CO π back‐donation, thus enabling the rapid desorption of CO and high selectivity for CO production. 相似文献
13.
二氧化碳(CO2)电催化还原反应利用可再生能源将CO2转化为高值燃料和化学品,是一种新型的碳中和技术。CO2电催化还原反应在电极/电解质界面上进行,因此除催化剂以外,电解质对提高CO2电催化还原反应性能同样至关重要。本文深度剖析了CO2电催化还原反应中的电解质效应,结合近几年的最新研究进展,详细讨论了局部p H、阳离子、阴离子和离子交换膜等电解质组成和性质对电催化活性和产物选择性的影响,阐述了电解质效应的催化作用机制。本文特别强调了电化学原位红外/拉曼等振动光谱在电解质效应机理研究方面的优势以及面向实际应用的膜电极CO2电解器中阴离子、阳离子、水、液体产物等物质传输对活性、选择性、能量效率及CO2利用效率等关键催化性能指标的影响。本文最后提出了当前电解质效应研究中存在的挑战,并展望了未来的研究机遇和发展趋势。 相似文献
14.
15.
16.
Single‐Shell Carbon‐Encapsulated Iron Nanoparticles: Synthesis and High Electrocatalytic Activity for Hydrogen Evolution Reaction
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mohammad Tavakkoli Dr. Tanja Kallio Olivier Reynaud Prof. Albert G. Nasibulin Dr. Christoffer Johans Dr. Jani Sainio Dr. Hua Jiang Prof. Esko I. Kauppinen Prof. Kari Laasonen 《Angewandte Chemie (International ed. in English)》2015,54(15):4535-4538
Efficient hydrogen evolution reaction (HER) through effective and inexpensive electrocatalysts is a valuable approach for clean and renewable energy systems. Here, single‐shell carbon‐encapsulated iron nanoparticles (SCEINs) decorated on single‐walled carbon nanotubes (SWNTs) are introduced as a novel highly active and durable non‐noble‐metal catalyst for the HER. This catalyst exhibits catalytic properties superior to previously studied nonprecious materials and comparable to those of platinum. The SCEIN/SWNT is synthesized by a novel fast and low‐cost aerosol chemical vapor deposition method in a one‐step synthesis. In SCEINs the single carbon layer does not prevent desired access of the reactants to the vicinity of the iron nanoparticles but protects the active metallic core from oxidation. This finding opens new avenues for utilizing active transition metals such as iron in a wide range of applications. 相似文献
17.
Dr. Wonhee Lee Young Eun Kim Dr. Min Hye Youn Dr. Soon Kwan Jeong Dr. Ki Tae Park 《Angewandte Chemie (International ed. in English)》2018,57(23):6883-6887
Electrochemical reduction of carbon dioxide (CO2) into value‐added chemicals is a promising strategy to reduce CO2 emission and mitigate climate change. One of the most serious problems in electrocatalytic CO2 reduction (CO2R) is the low solubility of CO2 in an aqueous electrolyte, which significantly limits the cathodic reaction rate. This paper proposes a facile method of catholyte‐free electrocatalytic CO2 reduction to avoid the solubility limitation using commercial tin nanoparticles as a cathode catalyst. Interestingly, as the reaction temperature rises from 303 K to 363 K, the partial current density (PCD) of formate improves more than two times with 52.9 mA cm?2, despite the decrease in CO2 solubility. Furthermore, a significantly high formate concentration of 41.5 g L?1 is obtained as a one‐path product at 343 K with high PCD (51.7 mA cm?2) and high Faradaic efficiency (93.3 %) via continuous operation in a full flow cell at a low cell voltage of 2.2 V. 相似文献
18.
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. 相似文献
19.
Lei Zhang Zichao Wei Srinivas Thanneeru Michael Meng Megan Kruzyk Gaël Ung Ben Liu Jie He 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(44):15981-15987
The stability of metal nanocatalysts for electrocatalytic CO2 reduction is of key importance for practical application. We report the use of two polymeric N‐heterocyclic carbenes (NHC) (polydentate and monodentate) to stabilize metal nanocatalysts (Au and Pd) for efficient CO2 electroreduction. Compared with other conventional ligands including thiols and amines, metal–carbene bonds that are stable under reductive potentials prevent the nanoclustering of nanoparticles. Au nanocatalysts modified by polymeric NHC ligands show an activity retention of 86 % after CO2 reduction at ?0.9 V for 11 h, while it is less than 10 % for unmodified Au. We demonstrate that the hydrophobicity of polymer ligands and the enriched surface electron density of metal NPs through σ‐donation of NHCs substantially improve the selectivity for CO2 reduction over proton. 相似文献
20.
Pig Bone Derived Hierarchical Porous Carbon‐Supported Platinum Nanoparticles with Superior Electrocatalytic Activity Towards Oxygen Reduction Reaction
下载免费PDF全文
![点击此处可从《Electroanalysis》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hierarchical porous carbon (HPC) with nitrogen doped three dimension open macropore structure was prepared from pig bone, and applied for the support material for platinum nanoparticle (Pt NP) electrocatalyst. Compared with carbon black supported Pt NP electrocatalysts, the Pt/HPC exhibited larger electrochemical active surface area and enhanced catalytic properties for the oxygen reduction reaction (ORR) in terms of on‐set potential, current density, mass activity and stability. The superior catalytic activity is mainly attributed to the high surface area, hierarchical porous structures and the nitrogen‐doped surface properties of the HPC, indicating it is a promising support material for the ORR electrocatalysts. 相似文献