共查询到20条相似文献,搜索用时 15 毫秒
1.
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. 相似文献
2.
Fei‐Yue Gao Shao‐Jin Hu Xiao‐Long Zhang Ya‐Rong Zheng Hui‐Juan Wang Zhuang‐Zhuang Niu Peng‐Peng Yang Rui‐Cheng Bao Tao Ma Zheng Dang Yong Guan Xu‐Sheng Zheng Xiao Zheng Jun‐Fa Zhu Min‐Rui Gao Shu‐Hong Yu 《Angewandte Chemie (International ed. in English)》2020,59(22):8706-8712
A considerable challenge in the conversion of carbon dioxide into useful fuels comes from the activation of CO2 to CO2.? or other intermediates, which often requires precious‐metal catalysts, high overpotentials, and/or electrolyte additives (e.g., ionic liquids). We report a microwave heating strategy for synthesizing a transition‐metal chalcogenide nanostructure that efficiently catalyzes CO2 electroreduction to carbon monoxide (CO). We found that the cadmium sulfide (CdS) nanoneedle arrays exhibit an unprecedented current density of 212 mA cm?2 with 95.5±4.0 % CO Faraday efficiency at ?1.2 V versus a reversible hydrogen electrode (RHE; without iR correction). Experimental and computational studies show that the high‐curvature CdS nanostructured catalyst has a pronounced proximity effect which gives rise to large electric field enhancement, which can concentrate alkali‐metal cations resulting in the enhanced CO2 electroreduction efficiency. 相似文献
3.
Yun‐Nan Gong Long Jiao Yunyang Qian Chun‐Yang Pan Lirong Zheng Xuechao Cai Bo Liu Shu‐Hong Yu Hai‐Long Jiang 《Angewandte Chemie (International ed. in English)》2020,59(7):2705-2709
The general synthesis and control of the coordination environment of single‐atom catalysts (SACs) remains a great challenge. Herein, a general host–guest cooperative protection strategy has been developed to construct SACs by introducing polypyrrole (PPy) into a bimetallic metal–organic framework. As an example, the introduction of Mg2+ in MgNi‐MOF‐74 extends the distance between adjacent Ni atoms; the PPy guests serve as N source to stabilize the isolated Ni atoms during pyrolysis. As a result, a series of single‐atom Ni catalysts (named NiSA‐Nx‐C) with different N coordination numbers have been fabricated by controlling the pyrolysis temperature. Significantly, the NiSA‐N2‐C catalyst, with the lowest N coordination number, achieves high CO Faradaic efficiency (98 %) and turnover frequency (1622 h?1), far superior to those of NiSA‐N3‐C and NiSA‐N4‐C, in electrocatalytic CO2 reduction. Theoretical calculations reveal that the low N coordination number of single‐atom Ni sites in NiSA‐N2‐C is favorable to the formation of COOH* intermediate and thus accounts for its superior activity. 相似文献
4.
Qun He Daobin Liu Ji Hoon Lee Yumeng Liu Zhenhua Xie Sooyeon Hwang Shyam Kattel Li Song Jingguang G. Chen 《Angewandte Chemie (International ed. in English)》2020,59(8):3033-3037
The electrochemical CO2 reduction reaction (CO2RR) to yield synthesis gas (syngas, CO and H2) has been considered as a promising method to realize the net reduction in CO2 emission. However, it is challenging to balance the CO2RR activity and the CO/H2 ratio. To address this issue, nitrogen‐doped carbon supported single‐atom catalysts are designed as electrocatalysts to produce syngas from CO2RR. While Co and Ni single‐atom catalysts are selective in producing H2 and CO, respectively, electrocatalysts containing both Co and Ni show a high syngas evolution (total current >74 mA cm?2) with CO/H2 ratios (0.23–2.26) that are suitable for typical downstream thermochemical reactions. Density functional theory calculations provide insights into the key intermediates on Co and Ni single‐atom configurations for the H2 and CO evolution. The results present a useful case on how non‐precious transition metal species can maintain high CO2RR activity with tunable CO/H2 ratios. 相似文献
5.
Qinggong Zhu Dexin Yang Huizhen Liu Xiaofu Sun Chunjun Chen Jiahui Bi Jiyuan Liu Haihong Wu Buxing Han 《Angewandte Chemie (International ed. in English)》2020,59(23):8896-8901
Electrocatalytic reduction of CO2 to a single product at high current densities and efficiencies remains a challenge. However, the conventional electrode preparation methods, such as drop‐casting, usually suffer from low intrinsic activity. Herein, we report a synthesis strategy for preparing heterogeneous electrocatalyst composed of 3D hierarchical Cu dendrites that derived from an in situ electrosynthesized hollow copper metal–organic framework (MOF), for which the preparation of the Cu‐MOF film took only 5 min. The synthesis strategy preferentially exposes active sites, which favor's the reduction of CO2 to formate. The current density could be as high as 102.1 mA cm?2 with a selectivity of 98.2 % in ionic‐liquid‐based electrolyte and a commonly used H‐type cell. 相似文献
6.
Converting CO2 into chemicals with electricity generated by renewable energy is a promising way to achieve the goal of carbon neutrality. Carbon-based materials have the advantages of low cost, wide sources and environmental friendliness. In this work, we prepared a series of boron-doped covalent triazine frameworks and found that boron doping can significantly improve the CO selectivity up to 91.2% in the CO2 electroreduction reactions(CO2RR). The effect of different doping ratios on the activity by adjusting the proportion of doped atoms was systematically investigated. This work proves that the doping modification of non-metallic materials is a very effective way to improve their activity, and also lays a foundation for the study of other element doping in the coming future. 相似文献
7.
Fa Yang Dr. Ping Song Xiaozhi Liu Bingbao Mei Prof. Wei Xing Prof. Zheng Jiang Prof. Lin Gu Prof. Weilin Xu 《Angewandte Chemie (International ed. in English)》2018,57(38):12303-12307
The electrochemical reduction reaction of carbon dioxide (CO2RR) to carbon monoxide (CO) is the basis for the further synthesis of more complex carbon‐based fuels or attractive feedstock. Single‐atom catalysts have unique electronic and geometric structures with respect to their bulk counterparts, thus exhibiting unexpected catalytic activities. A nitrogen‐anchored Zn single‐atom catalyst is presented for CO formation from CO2RR with high catalytic activity (onset overpotential down to 24 mV), high selectivity (Faradaic efficiency for CO (FECO) up to 95 % at ?0.43 V), remarkable durability (>75 h without decay of FECO), and large turnover frequency (TOF, up to 9969 h?1). Further experimental and DFT results indicate that the four‐nitrogen‐anchored Zn single atom (Zn‐N4) is the main active site for CO2RR with low free energy barrier for the formation of *COOH as the rate‐limiting step. 相似文献
8.
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
9.
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. 相似文献
10.
11.
12.
Shan Gao Xingchen Jiao Zhongti Sun Prof. Wenhua Zhang Prof. Yongfu Sun Dr. Chengming Wang Qitao Hu Xiaolong Zu Fan Yang Shuyang Yang Liang Liang Ju Wu Prof. Yi Xie 《Angewandte Chemie (International ed. in English)》2016,55(2):698-702
Electroreduction of CO2 into hydrocarbons could contribute to alleviating energy crisis and global warming. However, conventional electrocatalysts usually suffer from low energetic efficiency and poor durability. Herein, atomic layers for transition‐metal oxides are proposed to address these problems through offering an ultralarge fraction of active sites, high electronic conductivity, and superior structural stability. As a prototype, 1.72 and 3.51 nm thick Co3O4 layers were synthesized through a fast‐heating strategy. The atomic thickness endowed Co3O4 with abundant active sites, ensuring a large CO2 adsorption amount. The increased and more dispersed charge density near Fermi level allowed for enhanced electronic conductivity. The 1.72 nm thick Co3O4 layers showed over 1.5 and 20 times higher electrocatalytic activity than 3.51 nm thick Co3O4 layers and bulk counterpart, respectively. Also, 1.72 nm thick Co3O4 layers showed formate Faradaic efficiency of over 60 % in 20 h. 相似文献
13.
近几十年来,气候变暖、海平面上升等全球性气候问题日益严重,对人们赖以生存的自然环境造成了巨大的威胁.为了缓解并最终解决温室效应,多年来人们一直着手研究以二氧化碳(CO2)为主的温室气体的处理方法.CO2捕获和转化是一项新的技术,将捕获得到的CO2直接转化成甲酸、甲醇、甲烷等小分子有机物或药物中间体等高附加值的化合物.卟啉金属-有机框架(Porphyrin Metal-Organic Frameworks,PMOFs)是一种基于卟啉配体和金属节点的多孔配位框架材料.卟啉配体具有良好热稳定性、化学稳定性以及优异独特的光学性能,结合MOFs框架的多孔性带来的对CO2等气体分子的良好吸附性,使得PMOFs在CO2捕获与转化上具有巨大的潜力.首先,介绍了PMOFs合成中常用的构筑策略,包括拓扑导向、柱层策略以及金属-有机笼策略.然后,根据次级结构基元对常见的PMOFs结构进行系统分类,包括基于低价态金属离子、桨轮状M2(COO)4、金属-氧无限长链和硬酸金属-氧簇四类,叙述了各类PMOFs的结构特性和稳定性.随后,通过一些代表性的实例分类总结了PMOFs在CO2捕获与转化上的应用,包括CO2的捕获、环加成反应、光催化反应和电催化反应.最后,总结了PMOFs在四大类应用中具有的优势与挑战,并展望了PMOFs在CO2捕获与转化中的机遇和发展前景. 相似文献
14.
Tian Luo Prof. Dr. Jianling Zhang Xiuniang Tan Chengcheng Liu Dr. Tianbin Wu Dr. Wei Li Xinxin Sang Prof. Buxing Han Prof. Zhihong Li Dr. Guang Mo Dr. Xueqing Xing Prof. Zhonghua Wu 《Angewandte Chemie (International ed. in English)》2016,55(43):13533-13537
Herein we propose for the first time the utilization of a metal complex for forming water‐in‐supercritical CO2 (scCO2) microemulsions. The water solubility in the metal‐complex‐stabilized microemulsion is significantly improved compared with the conventional water‐in‐scCO2 microemulsions stabilized by hydrocarbons. Such a microemulsion provides a promising route for the in situ CO2 reduction catalyzed by a metal complex at the water/scCO2 interface. 相似文献
15.
Efficient CO2 Removal for Ultra‐Pure CO Production by Two Hybrid Ultramicroporous Materials
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)
Dr. Kai‐Jie Chen Dr. Qing‐Yuan Yang Dr. Susan Sen Dr. David G. Madden Amrit Kumar Dr. Tony Pham Katherine A. Forrest Dr. Nobuhiko Hosono Prof. Dr. Brian Space Prof. Dr. Susumu Kitagawa Prof. Dr. Michael J. Zaworotko 《Angewandte Chemie (International ed. in English)》2018,57(13):3332-3336
Removal of CO2 from CO gas mixtures is a necessary but challenging step during production of ultra‐pure CO as processed from either steam reforming of hydrocarbons or CO2 reduction. Herein, two hybrid ultramicroporous materials (HUMs), SIFSIX‐3‐Ni and TIFSIX‐2‐Cu‐i , which are known to exhibit strong affinity for CO2, were examined with respect to their performance for this separation. The single‐gas CO sorption isotherms of these HUMs were measured for the first time and are indicative of weak affinity for CO and benchmark CO2/CO selectivity (>4000 for SIFSIX‐3‐Ni ). This prompted us to conduct dynamic breakthrough experiments and compare performance with other porous materials. Ultra‐pure CO (99.99 %) was thereby obtained from CO gas mixtures containing both trace (1 %) and bulk (50 %) levels of CO2 in a one‐step physisorption‐based separation process. 相似文献
16.
We present herein a Cp*Co(III)‐half‐sandwich catalyst system for electrocatalytic CO2 reduction in aqueous acetonitrile solution. In addition to an electron‐donating Cp* ligand (Cp*=pentamethylcyclopentadienyl), the catalyst featured a proton‐responsive pyridyl‐benzimidazole‐based N,N‐bidentate ligand. Owing to the presence of a relatively electron‐rich Co center, the reduced Co(I)‐state was made prone to activate the electrophilic carbon center of CO2. At the same time, the proton‐responsive benzimidazole scaffold was susceptible to facilitate proton‐transfer during the subsequent reduction of CO2. The above factors rendered the present catalyst active toward producing CO as the major product over the other potential 2e/2H+ reduced product HCOOH, in contrast to the only known similar half‐sandwich CpCo(III)‐based CO2‐reduction catalysts which produced HCOOH selectively. The system exhibited a Faradaic efficiency (FE) of about 70% while the overpotential for CO production was found to be 0.78 V, as determined by controlled‐potential electrolysis. 相似文献
17.
Electrochemical reduction of carbon dioxide into value-added products is a promising way to recycle the greenhouse gas, thus solving the crisis of global warming. Pressing challenges remain in regulating the catalytic selectivity. In this work, we demonstrated a metal-organic frameworks-assisted approach to synthesizing In species loaded on the surface of N doped carbon matrix. By controlling the particle sizes, the catalytic selectivity can be easily altered. The obtained Inc/NC possesses the outstanding capability for converting CO2 into CO. And 80.09% Faraday efficiency (FE) of CO can be achieved at 0.8 V vs. RHE. While the In2O3/C exhibits different catalytic behaviors, the main product is formic acid and the FE is more than 50% at 0.8 V vs. RHE. The selectivity reversal can be attributed to the strong interactions between In clusters and N atoms of carbon supports, which efficiently inhibits the formation of the by-product, formic acid. Our research has paved a new way to modulate catalytic selectivity by manipulating the fine structures of the catalysts. 相似文献
18.
Fixation of CO2 by Pyrazolylborate‐Zinc‐Hydroxide Complexes The reversible uptake of CO2 by Tp*Zn‐OH complexes in alcoholic solutions with formation of Tp*Zn‐alkylcarbonate complexes was subjected to a comparative study. Its rate and the stability of its products depend on (1) the substituents in the 3‐positions of the pyrazolylborates (phenyl ≈ 3‐pyridyl ? t‐butyl), (2) the alcohol (CH3OH > C2H5OH). Traces of water seem to be essential for the formation of the Tp*Zn‐alkylcarbonates. In solution these are only stable in the presence of CO2. Two new alkylcarbonate complexes were obtained and characterized by structure determinations. 相似文献
19.
Xiaoxiao Yu Zhenzhen Yang Bing Qiu Shien Guo Peng Yang Bo Yu Hongye Zhang Yanfei Zhao Xinzheng Yang Buxing Han Zhimin Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(2):642-646
Visible‐light‐driven photoreduction of CO2 to energy‐rich chemicals in the presence of H2O without any sacrifice reagent is of significance, but challenging. Herein, Eosin Y‐functionalized porous polymers (PEosinY‐N, N=1–3), with high surface areas up to 610 m2 g?1, are reported. They exhibit high activity for the photocatalytic reduction of CO2 to CO in the presence of gaseous H2O, without any photosensitizer or sacrifice reagent, and under visible‐light irradiation. Especially, PEosinY‐1 derived from coupling of Eosin Y with 1,4‐diethynylbenzene shows the best performance for the CO2 photoreduction, affording CO as the sole carbonaceous product with a production rate of 33 μmol g?1 h?1 and a selectivity of 92 %. This work provides new insight for designing and fabricating photocatalytically active polymers with high efficiency for solar‐energy conversion. 相似文献
20.
Linsen Zhou Alexander Kandratsenka Charles T. Campbell Alec M. Wodtke Hua Guo 《Angewandte Chemie (International ed. in English)》2019,58(21):6916-6920
The post‐transition‐state dynamics in CO oxidation on Pt surfaces are investigated using DFT‐based ab initio molecular dynamics simulations. While the initial CO2 formed on a terrace site on Pt(111) desorbs directly, it is temporarily trapped in a chemisorption well on a Pt(332) step site. These two reaction channels thus produce CO2 with hyperthermal and thermal velocities with drastically different angular distributions, in agreement with recent experiments (Nature, 2018 , 558, 280–283). The chemisorbed CO2 is formed by electron transfer from the metal to the adsorbate, resulting in a bent geometry. While chemisorbed CO2 on Pt(111) is unstable, it is stable by 0.2 eV on a Pt(332) step site. This helps explain why newly formed CO2 produced at step sites desorbs with far lower translational energies than those formed at terraces. This work shows that steps and other defects could be potentially important in finding optimal conditions for the chemical activation and dissociation of CO2. 相似文献