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1.
Nan Zhang Leigang Li Juan Wang Zhiwei Hu Qi Shao Xiangheng Xiao Xiaoqing Huang 《Angewandte Chemie (International ed. in English)》2020,59(21):8066-8071
Surface regulation is an effective strategy to improve the performance of catalysts, but it has been rarely demonstrated for nitrogen reduction reaction (NRR) to date. Now, surface‐rough Rh2Sb nanorod (RNR) and surface‐smooth Rh2Sb NR (SNR) were selectively created, and their performance for NRR was investigated. The high‐index‐facet bounded Rh2Sb RNRs/C exhibit a high NH3 yield rate of 228.85±12.96 μg h?1 mg?1Rh at ?0.45 V versus reversible hydrogen electrode (RHE), outperforming the Rh2Sb SNRs/C (63.07±4.45 μg h?1 mg?1Rh) and Rh nanoparticles/C (22.82±1.49 μg h?1 mg?1Rh), owing to the enhanced adsorption and activation of N2 on high‐index facets. Rh2Sb RNRs/C also show durable stability with negligible activity decay after 10 h of successive electrolysis. The present work demonstrates that surface regulation plays an important role in promoting NRR activity and provides a new strategy for creating efficient NRR electrocatalysts. 相似文献
2.
Defect Engineering Metal‐Free Polymeric Carbon Nitride Electrocatalyst for Effective Nitrogen Fixation under Ambient Conditions
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Chade Lv Yumin Qian Chunshuang Yan Yu Ding Prof. Yuanyue Liu Prof. Gang Chen Prof. Guihua Yu 《Angewandte Chemie (International ed. in English)》2018,57(32):10246-10250
Electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions provides an intriguing picture for the conversion of N2 into NH3. However, electrocatalytic NRR mainly relies on metal‐based catalysts, and it remains a grand challenge in enabling effective N2 activation on metal‐free catalysts. Here we report a defect engineering strategy to realize effective NRR performance (NH3 yield: 8.09 μg h?1 mg?1cat., Faradaic efficiency: 11.59 %) on metal‐free polymeric carbon nitride (PCN) catalyst. Illustrated by density functional theory calculations, dinitrogen molecule can be chemisorbed on as‐engineered nitrogen vacancies of PCN through constructing a dinuclear end‐on bound structure for spatial electron transfer. Furthermore, the N?N bond length of adsorbed N2 increases dramatically, which corresponds to “strong activation” system to reduce N2 into NH3. This work also highlights the significance of defect engineering for improving electrocatalysts with weak N2 adsorption and activation ability. 相似文献
3.
Yao Yao Shangqian Zhu Haijiang Wang Hui Li Minhua Shao 《Angewandte Chemie (International ed. in English)》2020,59(26):10479-10483
Rh is a promising electrocatalyst for the nitrogen reduction reaction (NRR) given its suitable nitrogen‐adsorption energy and low overpotential. However, the NRR pathway on Rh surfaces remains unknown. In this study, we employ surface‐enhanced infrared‐absorption spectroscopy (SEIRAS) and differential electrochemical mass spectrometry (DEMS) to study the reaction mechanism of NRR on Rh. N2Hx (0≤x≤2) is detected with a N=N stretching mode at ≈2020 cm?1 by SEIRAS and a signal at m/z=29 by DEMS. A new two‐step reaction pathway on Rh surfaces is proposed that involves an electrochemical process with a two‐electron transfer to form N2H2 and its subsequent decomposition in the electrolyte producing NH3. Our results also indicate that nitrate reduction and the NRR share the same reaction intermediate N2Hx. 相似文献
4.
Jianyun Zheng Yanhong Lyu Man Qiao Jean P. Veder Roland D. Marco John Bradley Ruilun Wang Yafei Li Aibin Huang San Ping Jiang Shuangyin Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(51):18777-18782
The (photo)electrochemical N2 reduction reaction (NRR) provides a favorable avenue for the production of NH3 using renewable energy in mild operating conditions. Understanding and building an efficient catalyst with high NH3 selectivity represents an area of intense interest for the early stages of development for NRR. Herein, we introduce a CoOx layer to tune the local electronic structure of Au nanoparticles with positive valence sites for boosting conversion of N2 to NH3. The catalysts, possessing high average oxidation states (ca. 40 %), achieve a high NH3 yield rate of 15.1 μg cm?2 h?1 and a good faradic efficiency of 19 % at ?0.5 V versus reversible hydrogen electrode. Experimental results and simulations reveal that the ability to tune the oxidation state of Au enables the control of N2 adsorption and the concomitant energy barrier of NRR. Altering the Au oxidation state provides a unique strategy for control of NRR in the production of valuable NH3. 相似文献
5.
Tongwei Wu Xiaojuan Zhu Zhe Xing Shiyong Mou Chengbo Li Yanxia Qiao Qian Liu Yonglan Luo Xifeng Shi Yanning Zhang Xuping Sun 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(51):18620-18624
Titanium‐based catalysts are needed to achieve electrocatalytic N2 reduction to NH3 with a large NH3 yield and a high Faradaic efficiency (FE). One of the cheapest and most abundant metals on earth, iron, is an effective dopant for greatly improving the nitrogen reduction reaction (NRR) performance of TiO2 nanoparticles in ambient N2‐to‐NH3 conversion. In 0.5 m LiClO4, Fe‐doped TiO2 catalyst attains a high FE of 25.6 % and a large NH3 yield of 25.47 μg h?1 mgcat?1 at ?0.40 V versus a reversible hydrogen electrode. This performance compares favorably to those of all previously reported titanium‐ and iron‐based NRR electrocatalysts in aqueous media. The catalytic mechanism is further probed with theoretical calculations. 相似文献
6.
Dr. Honghong Liu Dr. Guangtong Hai Prof. Liang-Xin Ding Prof. Haihui Wang 《Angewandte Chemie (International ed. in English)》2023,62(19):e202302124
Electrocatalytic N2 reduction reaction (NRR) is recognized as a zero-carbon emission method for NH3 synthesis. However, to date, this technology still suffers from low yield and low selectivity associated with the catalyst. Herein, inspired by the activation of N2 by lithium metal, a highly reactive defective black phosphorene (D−BPene) is proposed as a lithium-like catalyst for boosting electrochemical N2 activation. Correspondingly, we also report a strategy for producing environmentally stable D−BPene by simultaneously constructing defects and fluorination protection based on topochemical reactions. Reliable performance evaluations show that the fluorine-stabilized D−BPene can induce a high NH3 yield rate of ≈70 μg h−1 mgcat.−1 and a high Faradaic efficiency of ≈26 % at −0.5 V vs. RHE in an aqueous electrolyte. This work not only exemplifies the first stable preparation and practical application of D−BPene, but also brings a new design idea for NRR catalysts. 相似文献
7.
Linlin Zhang Meiyu Cong Xin Ding Yu Jin Fanfan Xu Yong Wang Lin Chen Lixue Zhang 《Angewandte Chemie (International ed. in English)》2020,59(27):10888-10893
Electrochemical N2 reduction reactions (NRR) and the N2 oxidation reaction (NOR), using H2O and N2, are a sustainable approach to N2 fixation. To date, owing to the chemical inertness of nitrogen, emerging electrocatalysts for the electrochemical NRR and NOR at room temperature and atmospheric pressure remain largely underexplored. Herein, a new‐type Fe‐SnO2 was designed as a Janus electrocatalyst for achieving highly efficient NRR and NOR catalysis. A high NH3 yield of 82.7 μg h?1 mgcat.?1 and a Faraday efficiency (FE) of 20.4 % were obtained for NRR. This catalyst can also serve as an excellent NOR electrocatalyst with a NO3? yields of 42.9 μg h?1 mgcat.?1 and a FE of 0.84 %. By means of experiments and DFT calculations, it is revealed that the oxygen vacancy‐anchored single‐atom Fe can effectively adsorb and activate chemical inert N2 molecules, lowering the energy barrier for the vital breakage of N≡N and resulting in the enhanced N2 fixation performance. 相似文献
8.
Graphitic Carbon Nitride Nanoribbons: Graphene‐Assisted Formation and Synergic Function for Highly Efficient Hydrogen Evolution
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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
9.
Lili Zhang Liang‐Xin Ding Gao‐Feng Chen Xianfeng Yang Haihui Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(9):2638-2642
Constructing efficient catalysts for the N2 reduction reaction (NRR) is a major challenge for artificial nitrogen fixation under ambient conditions. Herein, inspired by the principle of “like dissolves like”, it is demonstrated that a member of the nitrogen family, well‐exfoliated few‐layer black phosphorus nanosheets (FL‐BP NSs), can be used as an efficient nonmetallic catalyst for electrochemical nitrogen reduction. The catalyst can achieve a high ammonia yield of 31.37 μg h?1 mg?1cat. under ambient conditions. Density functional theory calculations reveal that the active orbital and electrons of zigzag and diff‐zigzag type edges of FL‐BP NSs enable selective electrocatalysis of N2 to NH3 via an alternating hydrogenation pathway. This work proves the feasibility of using a nonmetallic simple substance as a nitrogen‐fixing catalyst and thus opening a new avenue towards the development of more efficient metal‐free catalysts. 相似文献
10.
Lili Han Xijun Liu Jinping Chen Ruoqian Lin Haoxuan Liu Fang Lü Seongmin Bak Zhixiu Liang Shunzheng Zhao Eli Stavitski Jun Luo Radoslav R. Adzic Huolin L. Xin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(8):2343-2347
NH3 synthesis by the electrocatalytic N2 reduction reaction (NRR) under ambient conditions is an appealing alternative to the currently employed industrial method—the Haber–Bosch process—that requires high temperature and pressure. We report single Mo atoms anchored to nitrogen‐doped porous carbon as a cost‐effective catalyst for the NRR. Benefiting from the optimally high density of active sites and hierarchically porous carbon frameworks, this catalyst achieves a high NH3 yield rate (34.0±3.6 μg h?1 mgcat.?1) and a high Faradaic efficiency (14.6±1.6 %) in 0.1 m KOH at room temperature. These values are considerably higher compared to previously reported non‐precious‐metal electrocatalysts. Moreover, this catalyst displays no obvious current drop during a 50 000 s NRR, and high activity and durability are achieved in 0.1 m HCl. The findings provide a promising lead for the design of efficient and robust single‐atom non‐precious‐metal catalysts for the electrocatalytic NRR. 相似文献
11.
Dimeric rhodium(I) complex [Rh(OMe)(cod)]2 was found to be an active catalyst of phenylacetylene polymerization to poly(phenylacetylene) (PPA) in ionic liquids containing imidazolium or pyridinium cations. The highest yield of PPA (92%) was obtained in 1‐butyl‐4‐methylpyridinium tetrafluoroborate as reaction medium. The yield of PPA in imidazolium ionic liquids containing BF4? or PF6? anions increased to 83–99% when Et3N or cycloocta‐1,5‐diene were added as co‐catalysts. In 1‐methyl‐3‐octylimidazolium chloride (MOI · Cl) polymerization rate was much lower than in other ionic liquids, although the highest Mw (72 400) was obtained. Spectroscopic studies confirmed that [Rh(OMe)(cod)]2 reacted with MOI · Cl forming new carbene Rh(I) complex, which can participate in the polymerization process. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
12.
Nan Zhang Dr. Leigang Li Juan Wang Dr. Zhiwei Hu Dr. Qi Shao Prof. Xiangheng Xiao Prof. Xiaoqing Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(21):8143-8148
Surface regulation is an effective strategy to improve the performance of catalysts, but it has been rarely demonstrated for nitrogen reduction reaction (NRR) to date. Now, surface-rough Rh2Sb nanorod (RNR) and surface-smooth Rh2Sb NR (SNR) were selectively created, and their performance for NRR was investigated. The high-index-facet bounded Rh2Sb RNRs/C exhibit a high NH3 yield rate of 228.85±12.96 μg h−1 mg−1Rh at −0.45 V versus reversible hydrogen electrode (RHE), outperforming the Rh2Sb SNRs/C (63.07±4.45 μg h−1 mg−1Rh) and Rh nanoparticles/C (22.82±1.49 μg h−1 mg−1Rh), owing to the enhanced adsorption and activation of N2 on high-index facets. Rh2Sb RNRs/C also show durable stability with negligible activity decay after 10 h of successive electrolysis. The present work demonstrates that surface regulation plays an important role in promoting NRR activity and provides a new strategy for creating efficient NRR electrocatalysts. 相似文献
13.
Weikang Wang Haimin Zhang Shengbo Zhang Yanyan Liu Guozhong Wang Chenghua Sun Huijun Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(46):16797-16803
As a metal‐free nitrogen reduction reaction (NRR) photocatalyst, g‐C3N4 is available from a scalable synthesis at low cost. Importantly, it can be readily functionalized to enhance photocatalytic activities. However, the use of g‐C3N4‐based photocatalysts for the NRR has been questioned because of the elusive mechanism and the involvement of N defects. This work reports the synthesis of a g‐C3N4 photocatalyst modified with cyano groups and intercalated K+ (mCNN), possessing extended visible‐light harvesting capacity and superior photocatalytic NRR activity (NH3 yield: 3.42 mmol g?1 h?1). Experimental and theoretical studies suggest that the ‐C≡N in mCNN can be regenerated through a pathway analogous to Mars van Krevelen process with the aid of the intercalated K+. The results confirm that the regeneration of the cyano group not only enhances photocatalytic activity and sustains the catalytic cycle, but also stabilizes the photocatalyst. 相似文献
14.
Wence Xu Guilan Fan Jialiang Chen Jinhan Li Le Zhang Shengli Zhu Xuncheng Su Fangyi Cheng Jun Chen 《Angewandte Chemie (International ed. in English)》2020,59(9):3511-3516
The electrocatalytic nitrogen reduction reaction (NRR) is an alternative eco‐friendly strategy for sustainable N2 fixation with renewable energy. However, NRR suffers from sluggish kinetics owing to difficult N2 adsorption and N≡N cleavage. Now, nanoporous palladium hydride is reported as electrocatalyst for electrochemical N2 reduction under ambient conditions, achieving a high ammonia yield rate of 20.4 μg h?1 mg?1 with a Faradaic efficiency of 43.6 % at low overpotential of 150 mV. Isotopic hydrogen labeling studies suggest the involvement of lattice hydrogen atoms in the hydride as active hydrogen source. In situ Raman analysis and density functional theory (DFT) calculations further reveal the reduction of energy barrier for the rate‐limiting *N2H formation step. The unique protonation mode of palladium hydride would provide a new insight on designing efficient and robust electrocatalysts for nitrogen fixation. 相似文献
15.
Yuanyuan Yang Lifu Zhang Zhenpeng Hu Yao Zheng Cheng Tang Ping Chen Ruguang Wang Kangwen Qiu Jing Mao Tao Ling Shi‐Zhang Qiao 《Angewandte Chemie (International ed. in English)》2020,59(11):4525-4531
Cost‐effective carbon‐based catalysts are promising for catalyzing the electrochemical N2 reduction reaction (NRR). However, the activity origin of carbon‐based catalysts towards NRR remains unclear, and regularities and rules for the rational design of carbon‐based NRR electrocatalysts are still lacking. Based on a combination of theoretical calculations and experimental observations, chalcogen/oxygen group element (O, S, Se, Te) doped carbon materials were systematically evaluated as potential NRR catalysts. Heteroatom‐doping‐induced charge accumulation facilitates N2 adsorption on carbon atoms and spin polarization boosts the potential‐determining step of the first protonation to form *NNH. Te‐doped and Se‐doped C catalysts exhibited high intrinsic NRR activity that is superior to most metal‐based catalysts. Establishing the correlation between the electronic structure and NRR performance for carbon‐based materials paves the pathway for their NRR application. 相似文献
16.
Abstract The synthesis of D,L‐α‐tocopherol from trimethylhydroquinone and isophytol using the Brønsted acidic SO3H‐functionalized ionic liquids as catalysts was explored. The catalytic activities of the SO3H‐functionalized ionic liquids were dependent on their anions. The yield of D,L‐α‐tocopherol also depended on the solvent, which was the reaction medium. A yield of 94.3% was obtained using the SO3H‐functionalized ionic liquid with [BF4 ?] anion as catalyst in propylene carbonate/heptane. The reaction mixture exhibited good biphasic behaviors, so that the produced D,L‐α‐tocopherol could be separated by decantation. The SO3H‐functionalized ionic liquids could be reused after the removal of water. 相似文献
17.
Heck reaction of iodoarenes with methyl acrylate, catalyzed by cyclolmlladated complexes of tertiary arylamines, was investi-gated in ionic liquid 1-butyl-3-metylimidazolium tetratluorobo-rate ([Bmim] BF4^- ). The products can be isolated convenient-ly from the ionic liquid-catalyst system. The catalysts could be reused for more than 10 times still with satisfactory catalytic ac-tivity. 相似文献
18.
《中国化学快报》2023,34(1):107282
NH3 plays an essential role in human life since it is an important raw material for fertilizers, plastics and rubbers production. As an NH3 synthesis technology under ambient conditions, electrocatalytic N2 reduction reaction (NRR) has great potential to replace the energy-intensive Haber-Bosch process. The key of electrocatalytic NRR is the exploration of efficient catalysts. Transition metal Mo is promising since it exists naturally in nitrogenase due to the unique Mo-N2 interaction; particularly in the form of 2D material such as MoSe2, the surface area is maximized for more active sites. However, the NRR performance of MoSe2 is still unsatisfactory because Mo is only exposed at the semi-open edge, and the electronegative Se-mantled surface area remains inaccessible to N2. Herein, we propose a simple and effective strategy to create high-concentration Se vacancies in MoSe2 through heteroatom doping induced lattice strain, which effectively enhances the Mo-N2 interaction on the surface area. In result, high NH3 yield (3.04 × 10–10 mol s–1 cm–2) and Faraday efficiency (21.61%) are attained at –0.45 V vs. RHE in 0.1 mol/L Na2SO4. 相似文献
19.
Yamei Li Yoo Kyung Go Hideshi Ooka Daoping He Fangming Jin Sun Hee Kim Ryuhei Nakamura 《Angewandte Chemie (International ed. in English)》2020,59(24):9744-9750
Nitrate is a pervasive aquatic contaminant of global environmental concern. In nature, the most effective nitrate reduction reaction (NRR) is catalyzed by nitrate reductase enzymes at neutral pH, using a highly‐conserved Mo center ligated mainly by oxo and thiolate groups. Mo‐based NRR catalysts mostly function in organic solvents with a low water stability. Recently, an oxo‐containing molybdenum sulfide nanoparticle that serves as an NRR catalyst at neutral pH was first reported. Herein, in a nanoparticle‐catalyzed NRR system a pentavalent MoV(=O)S4 species, an enzyme mimetic, served as an active intermediate for the NRR. Potentiometric titration analysis revealed that a redox synergy among MoV?S, S radicals, and MoV(=O)S4 likely play a key role in stabilizing MoV(=O)S4, showing the importance of secondary interactions in facilitating NRR. The first identification and characterization of an oxo‐ and thiolate‐ligated Mo intermediates pave the way to the molecular design of efficient enzyme mimetic NRR catalysts in aqueous solution. 相似文献
20.
Veronika Strehmel Dr. Hans Rexhausen Dr. Peter Strauch Prof. Eckhard Görnitz Dr. Bernd Strehmel Dr. 《Chemphyschem》2008,9(9):1294-1302
2,2,6,6‐Tetramethylpiperidine‐1‐yloxyl derivatives substituted with either hydrogen bonding [‐OH, ‐OSO3H] or ionic [‐OSO3?Na+, ‐OSO3?K+, N+(CH3)3I?, N+(CH3)3 N?(SO2‐CF3)2] substituents are investigated in 1‐butyl‐3‐methylimidazolium tetrafluoroborate over a wide temperature range covering both glassy and viscous states. The Vogel–Fulcher–Tammann equation describes the temperature dependence of the ionic liquid viscosity. Quantum chemical calculations of the spin probes at the UB3LYP/6‐311(2d,p++) level are done to describe the dependence of the spin density on nitrogen on the substitution pattern of the 4‐position of the probe. The results of these calculations are also used to understand the experimental results obtained by applying the Spernol–Gierer–Wirtz theory to analyze the viscosity dependence of the rotational correlation time of the spin probes. Significant differences are found between 2,2,6,6‐tetramethylpiperidine‐1‐yloxyl and its derivatives containing substituents that are able to form hydrogen bonds with the ionic liquid. Moreover, derivatives substituted with ionic groups at the 4‐position have a large effect on temperature‐induced solvent viscosity, as this is particularly dependent on the nature of the substituent at the 4‐position. These dependencies include the temperature region that can be used to describe interactions between the spin probes and the ionic liquid, diffusion into the free volume during non‐activated (neutral spin probes) and activated (charged spin probes) processes. Additional parameters are the radii of the ionic liquid and the spin probes, which are calculated and measured approximately. In addition, the temperature dependence of the isotropic hyperfine coupling constants of the spin probes results in information about the micropolarity of the ionic liquid. At room temperature, this is comparable to that of the solvent dimethylsulfoxide. 相似文献