共查询到20条相似文献,搜索用时 62 毫秒
1.
Dr. Chuangang Hu Prof. Liming Dai 《Angewandte Chemie (International ed. in English)》2016,55(39):11736-11758
Besides their use in fuel cells for energy conversion through the oxygen reduction reaction (ORR), carbon‐based metal‐free catalysts have also been demonstrated to be promising alternatives to noble‐metal/metal oxide catalysts for the oxygen evolution reaction (OER) in metal–air batteries for energy storage and for the splitting of water to produce hydrogen fuels through the hydrogen evolution reaction (HER). This Review focuses on recent progress in the development of carbon‐based metal‐free catalysts for the OER and HER, along with challenges and perspectives in the emerging field of metal‐free electrocatalysis. 相似文献
2.
Lu Wang Dr. Adriano Ambrosi Prof. Martin Pumera 《Angewandte Chemie (International ed. in English)》2013,52(51):13818-13821
The oxygen reduction reaction (ORR) is of high industrial importance. There is a large body of literature showing that metal‐based catalytic nanoparticles (e.g. Co, Mn, Fe or hybrid Mn/Co‐based nanoparticles) supported on graphene act as efficient catalysts for the ORR. A significant research effort is also directed to the so‐called “metal‐free” oxygen reduction reaction on heteroatom‐doped graphene surfaces. While such studies of the ORR on nonmetallic heteroatom‐doped graphene are advertised as “metal‐free” there is typically no sufficient effort to characterize the doped materials to verify that they are indeed free of any trace metal. Here we argue that the claimed “metal‐free” electrocatalysis of the oxygen reduction reaction on heteroatom‐doped graphene is caused by metallic impurities present within the graphene materials. 相似文献
3.
Active oxygen evolution reaction electrocatalysts for water splitting have received great attention because of their importance in the utilization of renewable energy sources. Here, the electrochemical oxygen evolution reaction activities of a nanoporous gold (NPG)‐based electrode in acidic media are investigated. The dependence of the oxygen evolution reaction activity on the NPG surface area shows that the large electrochemical surface areas of the NPG are effectively utilized to enhance electrocatalytic activity. The NPG surfaces are modified with Pt using atomic layer electrodeposition methods, and the resulting NPG@Pt exhibited enhanced electrocatalytic activities compared to those of the NPG and flat Pt electrodes. Ir‐modified NPG (NPG@Ir) electrodes are prepared by spontaneous exchange of Ir on NPG surfaces and exhibit enhanced electrocatalytic activity compared to that of flat Ir surfaces. The modification of NPG@Pt with Ir results in NPG@Pt/Ir electrodes, and their electrocatalytic activities exceed those of NPG@Ir. The enhanced oxygen evolution reaction activity on NPG@Pt/Ir over that on NPG@Ir surfaces is examined by X‐ray photoelectron spectroscopy. The oxygen evolution reaction activity on NPG@Pt/Ir surfaces demonstrates synergistic electrocatalysis between the nanoporous surface structure and active electrocatalytic components. 相似文献
4.
5.
Haonan Qin Yanzhi Wang Bin Wang Xiaoguang Duan Haitao Lei Xuepeng Zhang Haoquan Zheng Wei Zhang Rui Cao 《Journal of Energy Chemistry》2021,(2):77-81,I0003
Transition-metal based M-N_4/C catalysts are appealing for electrocatalytic oxygen reduction reaction(ORR) and oxygen evolution reaction(OER). Employing model catalysts, which have well-defined molecular structures and coordination environments, to investigate electrocatalytic performance of M-N_4/C sites for ORR and OER is of fundamental significance. Herein, we reported the use of Co tetra(phenyl)porphyrin 1 and Co tetra(pentafluorophenyl)porphyrin 2 as models to probe the role of Co-N_4/C sites for oxygen electrocatalysis. We showed that Co porphyrin 1 is more efficient than its structural analogue 2 for oxygen electrocatalysis in alkaline aqueous solutions, indicating that the electronrich Co-N_4/C site is more favored when noncovalently adsorbed on carbon supports. This work inspires rational design of reaction-oriented catalysts for sustainable energy storage and conversion technologies. 相似文献
6.
Jintao Zhang Liming Dai 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(42):13490-13494
Electrocatalysts are required for clean energy technologies (for example, water‐splitting and metal‐air batteries). The development of a multifunctional electrocatalyst composed of nitrogen, phosphorus, and fluorine tri‐doped graphene is reported, which was obtained by thermal activation of a mixture of polyaniline‐coated graphene oxide and ammonium hexafluorophosphate (AHF). It was found that thermal decomposition of AHF provides nitrogen, phosphorus, and fluorine sources for tri‐doping with N, P, and F, and simultaneously facilitates template‐free formation of porous structures as a result of thermal gas evolution. The resultant N, P, and F tri‐doped graphene exhibited excellent electrocatalytic activities for the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). The trifunctional metal‐free catalyst was further used as an OER–HER bifunctional catalyst for oxygen and hydrogen gas production in an electrochemical water‐splitting unit, which was powered by an integrated Zn–air battery based on an air electrode made from the same electrocatalyst for ORR. The integrated unit, fabricated from the newly developed N, P, and F tri‐doped graphene multifunctional metal‐free catalyst, can operate in ambient air with a high gas production rate of 0.496 and 0.254 μL s−1 for hydrogen and oxygen gas, respectively, showing great potential for practical applications. 相似文献
7.
Xiaojing Long Daohao Li Binbin Wang Zhenjie Jiang Wenjia Xu Bingbing Wang Dongjiang Yang Yanzhi Xia 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(33):11491-11495
Exploring cost‐effective and efficient metal‐free electrocatalysts for the oxygen reduction reaction (ORR) is crucial for the development of energy conversion and storage technologies. Reported here is a novel heterocyclization strategy to construct efficient ORR catalysts based on linear conjugated polymers (LCPs), which are composed of N‐, S‐, or Se‐heterocycles. Among these polymers, the covalently linked pyridine and thiophene molecule ( P‐T ) with reduced graphene oxide (rGO) exhibits a remarkable half‐wave potential of 0.79 V (vs. RHE) and excellent electrochemical stability, which are among the highest values for metal‐free polymers as ORR catalysts. Density‐functional theory (DFT) calculations reveal that the molecule with a phenyl unit ( P‐Ph ) is catalytically inactive, and when a thiophene unit is introduced to replace the phenyl unit in the conjugated backbone it features highly efficient electrocatalytic active sites. More importantly, the well‐defined molecular structures and controllable active sites in the pyrolysis and metal‐free polymers highlight new opportunities for the catalytic metal‐free ORR. 相似文献
8.
A Strongly Coupled Graphene and FeNi Double Hydroxide Hybrid as an Excellent Electrocatalyst for the Oxygen 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)
Xia Long Jinkai Li Shuang Xiao Keyou Yan Zilong Wang Haining Chen Shihe Yang 《Angewandte Chemie (International ed. in English)》2014,53(29):7584-7588
Cost‐effective electrocatalysts for the oxygen evolution reaction (OER) are critical to energy conversion and storage processes. A novel strategy is used to synthesize a non‐noble‐metal‐based electrocatalyst of the OER by finely combining layered FeNi double hydroxide that is catalytically active and electric conducting graphene sheets, taking advantage of the electrostatic attraction between the two positively charged nanosheets. The synergy between the catalytic activity of the double hydroxide and the enhanced electron transport arising from the graphene resulted in superior electrocatalytic properties of the FeNi‐GO hybrids for the OER with overpotentials as low as 0.21 V, which was further reduced to 0.195 V after the reduction treatment. Moreover, the turnover frequency at the overpotential of 0.3 V has reached 1 s?1, which is much higher than those previously reported for non‐noble‐metal‐based electrocatalysts. 相似文献
9.
Nitrogen,Phosphorus, and Fluorine Tri‐doped Graphene as a Multifunctional Catalyst for Self‐Powered Electrochemical Water Splitting
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. Jintao Zhang Prof. Liming Dai 《Angewandte Chemie (International ed. in English)》2016,55(42):13296-13300
Electrocatalysts are required for clean energy technologies (for example, water‐splitting and metal‐air batteries). The development of a multifunctional electrocatalyst composed of nitrogen, phosphorus, and fluorine tri‐doped graphene is reported, which was obtained by thermal activation of a mixture of polyaniline‐coated graphene oxide and ammonium hexafluorophosphate (AHF). It was found that thermal decomposition of AHF provides nitrogen, phosphorus, and fluorine sources for tri‐doping with N, P, and F, and simultaneously facilitates template‐free formation of porous structures as a result of thermal gas evolution. The resultant N, P, and F tri‐doped graphene exhibited excellent electrocatalytic activities for the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). The trifunctional metal‐free catalyst was further used as an OER–HER bifunctional catalyst for oxygen and hydrogen gas production in an electrochemical water‐splitting unit, which was powered by an integrated Zn–air battery based on an air electrode made from the same electrocatalyst for ORR. The integrated unit, fabricated from the newly developed N, P, and F tri‐doped graphene multifunctional metal‐free catalyst, can operate in ambient air with a high gas production rate of 0.496 and 0.254 μL s?1 for hydrogen and oxygen gas, respectively, showing great potential for practical applications. 相似文献
10.
《应用有机金属化学》2017,31(10)
Iron‐ and nitrogen‐functionalized graphene (Fe‐N‐G), as well as iron‐ and nitrogen‐functionalized oxidized graphene (Fe‐N‐Gox) catalysts were synthesized as non‐noble metal electrocatalysts for oxygen reduction reaction (ORR). The physical properties of the resultant catalysts were characterized using nitrogen adsorption measurements, X‐ray diffraction, Raman and X‐ray photoelectron spectroscopies and transmission electron microscopy. Subsequently, ORR activities of the catalysts were determined electrochemically using a conventional three‐electrode cell via cyclic voltammetry with a rotating disc electrode, the results of which indicated that the synthesized catalysts had a marked electrocatalytic activity towards ORR in acid media. Among the synthesized catalysts, that functionalized using 2,4,6‐tris(2‐pyridyl)‐1,3,5‐triazine as nitrogen source had the highest electrocatalytic activity with the highest onset potential (0.98 V/SHE) and limiting current density (5.12 mA cm−2). The findings are particularly important to determine a non‐precious metal catalyst for ORR activity in fuel cells. 相似文献
11.
《中国化学快报》2021,32(9):2841-2845
Substituent effect of metal porphyrin molecular catalysts plays a crucial role in determining the catalytic activity of oxygen electrocatalysis. Herein, substituent position effect of Co porphyrins on oxygen electrocatalysis, including the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER), was investigated. Two Co porphyrins, namely 2,4,6-OMe-CoP and 3,4,5-OMe-CoP, were selected as the research objects. The ORR and OER performance was evaluated by drop-coating molecular catalysts on carbon nanotubes (CNTs). The resulted 3,4,5-OMe-CoP/CNT exhibited high bifunctional electrocatalytic activities and better long-term stability for both ORR and OER than 2,4,6-OMe-CoP/CNT. Furthermore, when applied in the Zn-air battery, 3,4,5-OMe-CoP/CNT exhibited comparable performance to that with precious metal-based materials. The enhanced catalytic activity may be attributed to the improved charge transfer rate, mass transfer and hydrophilicity. This work provides an effective strategy to further enhance catalytic activity by introducing substituent position effect, which is of great importance for developing more efficient energy-related electrocatalysts. 相似文献
12.
Graphitic Carbon Nitride Nanoribbons: Graphene‐Assisted Formation and Synergic Function for Highly Efficient Hydrogen Evolution
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)
Yang Zhao Fei Zhao Xiaopeng Wang Chenyu Xu Zhipan Zhang Prof. Gaoquan Shi Prof. Liangti Qu 《Angewandte Chemie (International ed. in English)》2014,53(50):13934-13939
The development of new promising metal‐free catalysts is of great significance for the electrocatalytic hydrogen evolution reaction (HER). Herein, a rationally assembled three‐dimensional (3D) architecture of 1D graphitic carbon nitride (g‐C3N4) nanoribbons with 2D graphene sheets has been developed by a one‐step hydrothermal method. Because of the multipathway of charge and mass transport, the hierarchically structured g‐C3N4 nanoribbon–graphene hybrids lead to a high electrocatalytic ability for HER with a Tafel slope of 54 mV decade?1, a low onset overpotential of 80 mV and overpotential of 207 mV to approach a current of 10 mA cm?2, superior to those non‐metal materials and well‐developed metallic catalysts reported previously. This work presents a great advance for designing and developing highly efficient metal‐free catalyst for hydrogen evolution. 相似文献
13.
Three‐Dimensional Branched and Faceted Gold–Ruthenium Nanoparticles: Using Nanostructure to Improve Stability in Oxygen Evolution Electrocatalysis
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. Lucy Gloag Dr. Tania M. Benedetti Dr. Soshan Cheong Dr. Yibing Li Dr. Xuan‐Hao Chan Prof. Lise‐Marie Lacroix Prof. Shery L. Y. Chang Dr. Raul Arenal Dr. Ileana Florea Dr. Hector Barron Dr. Amanda S. Barnard Dr. Anna M. Henning Prof. Chuan Zhao Prof. Wolfgang Schuhmann Prof. J. Justin Gooding Prof. Richard D. Tilley 《Angewandte Chemie (International ed. in English)》2018,57(32):10241-10245
Achieving stability with highly active Ru nanoparticles for electrocatalysis is a major challenge for the oxygen evolution reaction. As improved stability of Ru catalysts has been shown for bulk surfaces with low‐index facets, there is an opportunity to incorporate these stable facets into Ru nanoparticles. Now, a new solution synthesis is presented in which hexagonal close‐packed structured Ru is grown on Au to form nanoparticles with 3D branches. Exposing low‐index facets on these 3D branches creates stable reaction kinetics to achieve high activity and the highest stability observed for Ru nanoparticle oxygen evolution reaction catalysts. These design principles provide a synthetic strategy to achieve stable and active electrocatalysts. 相似文献
14.
15.
Antoine Bonnefont Anna S. Ryabova Tiphaine Schott Gwénaëlle Kéranguéven Sergey Ya. Istomin Evgeny V. Antipov Elena R. Savinova 《Current Opinion in Electrochemistry》2019
Transition metal oxides are attractive noble metal-free catalysts of the oxygen reduction for application at the cathode of alkaline membrane fuel cells or metal-air batteries. However, despite of a rapidly increasing number of publications devoted to the oxygen electrocatalysis on transition metal oxides, a clear picture regarding the relations between their structure and composition on the one hand and electrocatalytic activity on the other hand is lacking. This short review discusses challenges facing researchers seeking to understand electrocatalysis of the oxygen reduction reaction on transition metal oxides. 相似文献
16.
Sulfur‐Doped Graphene Derived from Cycled Lithium–Sulfur Batteries as a Metal‐Free Electrocatalyst for the Oxygen Reduction 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)
Zhaoling Ma Shuo Dou Anli Shen Li Tao Prof. Liming Dai Prof. Shuangyin Wang 《Angewandte Chemie (International ed. in English)》2015,54(6):1888-1892
Heteroatom‐doped carbon materials have been extensively investigated as metal‐free electrocatalysts to replace commercial Pt/C catalysts in oxygen reduction reactions in fuel cells and Li–air batteries. However, the synthesis of such materials usually involves high temperature or complicated equipment. Graphene‐based sulfur composites have been recently developed to prolong the cycling life of Li–S batteries, one of the most attractive energy‐storage devices. Given the high cost of graphene, there is significant demand to recycle and reuse graphene from Li–S batteries. Herein, we report a green and cost‐effective method to prepare sulfur‐doped graphene, achieved by the continuous charge/discharge cycling of graphene–sulfur composites in Li–S batteries. This material was used as a metal‐free electrocatalyst for the oxygen reduction reaction and shows better electrocatalytic activity than pristine graphene and better methanol tolerance durability than Pt/C. 相似文献
17.
Metal–organic frameworks (MOFs) possess fantastic features such as structural diversity, tunable accessible pores and atomically dispersed active sites, holding tremendous potential as highly versatile platforms for fabricating single-site catalysts. The electrocatalytic activity of single-site MOFs can be improved and tuned via several approaches; however, the exploitation of different carbon supports to modulate the nature of single active sites in MOFs for electrocatalysis has not been reported. Here, we find that the electrocatalytic activity of single-site MOFs toward the oxygen reduction reaction (ORR) can be tuned by using carbon nanomaterials, i.e., carbon nanotubes and graphene, as supports through MOF–support interactions in the manner of geometric and electronic effects. The introduction of MOF–support interactions not only greatly improves the electrocatalytic performance of MOFs toward the ORR in terms of onset and half-wave potentials and current density, but also alters the reaction pathway of the ORR. This finding provides a new horizon for the design and synthesis of single-site MOFs for electrocatalysis.MOF–support interactions are proposed for the first time for tuning the electrocatalytic activity of single-site MOFs in the manner of geometric and electronic effects. 相似文献
18.
Haiyan Xiang Yueshao Zheng Yang Chen Yanting Xu Travis Shihao Hu Yexin Feng Yu Zhou Song Liu Xuli Chen 《中国化学快报》2022,33(6):3221-3226
Semiconductor electrocatalysis with weak conductivity can accumulate extremely high carriers at semiconductor-electrolyte interface by self-gating effect, which strongly promotes electrocatalytic efficiency. The correlation between semiconductor carrier mobility and electrocatalysis performance is still unclear. Herein atomic-thin transition metal dichalcogenides based composites have been developed for hydrogen evolution reaction(HER) performed with on-chip microdevices. Electrical and electroc... 相似文献
19.
Chun Kiang Chua Adeline Huiling Loo Prof. Martin Pumera 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(17):5969-5975
Tailoring and enhancing electrocatalytic activity is of the utmost importance from the viewpoints of sustainable energy and sensing. MoS2 and graphene show great promise for the electrocatalysis of many reactions. Given that both graphene and MoS2 are highly anisotropic in nature, with edge planes that are several orders of magnitude more catalytically active than basal planes, a new hybrid material with maximized edge‐plane density to provide efficient electron transfer, high catalytic activity, and conductive cores was engineered. The hybrid material consists of radial MoS2 nanosheets with a high density of edge planes and unsaturated active sulfur atoms as well as interspersed with conductive graphene nanoplatelets. This hybrid material exhibits excellent activity for the hydrogen evolution reaction and the detection of DNA nucleobases. Such a nanoengineered, nanostructured hybrid material may play a major role in future electrocatalytic devices. 相似文献
20.
This review gives an overview of the electrochemical investigations about the properties of various types of graphene composites in the ethanol oxidation. Various routes to provide appropriate graphene‐based materials required electrochemical techniques for investigation of different types of the materials as well as their performance and efficacy in ethanol oxidation are discussed in detail. Furthermore, it is demonstrated that the incorporation of suitable materials, e. g. noble metals (graphene‐supported binary and ternary metal nanoparticles), metal oxides, conductive polymer, etc, with graphene results in excellent electrocatalytic activity, superb durability and selectivity in ethanol oxidation. Immobilization of electrocatalytically active NPs on graphene supports using physical approaches is considered as an effective route to prepare direct ethanol fuel cell (DEFC) anode catalysts. 相似文献