共查询到20条相似文献,搜索用时 31 毫秒
1.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(42):13315-13319
A surface‐restructuring strategy is presented that involves self‐cleaning Cu catalyst electrodes with unprecedented catalytic stability toward CO2 reduction. Under the working conditions, the Pd atoms pre‐deposited on Cu surface induce continuous morphological and compositional restructuring of the Cu surface, which constantly refreshes the catalyst surface and thus maintains the catalytic properties for CO2 reduction to hydrocarbons. The Pd‐decorated Cu electrode can catalyze CO2 reduction with relatively stable selectivity and current density for up to 16 h, which is one of the best catalytic durability performances among all Cu electrocatalysts for effective CO2 conversion to hydrocarbons. The generality of this approach of utilizing foreign metal atoms to induce surface restructuring toward stabilizing Cu catalyst electrodes against deactivation by carbonaceous species accumulation in CO2 reduction is further demonstrated by replacing Pd with Rh. 相似文献
2.
Tian Wang Jiadong Chen Xinyi Ren Jincheng Zhang Jie Ding Yuhang Liu Kang Hui Lim Junhu Wang Xuning Li Hongbin Yang Yanqiang Huang Sibudjing Kawi Bin Liu 《Angewandte Chemie (International ed. in English)》2023,62(10):e202211174
Electrochemically reducing CO2 to valuable fuels or feedstocks is recognized as a promising strategy to simultaneously tackle the crises of fossil fuel shortage and carbon emission. Sn-based catalysts have been widely studied for electrochemical CO2 reduction reaction (CO2RR) to make formic acid/formate, which unfortunately still suffer from low activity, selectivity and stability. In this work, halogen (F, Cl, Br or I) was introduced into the Sn catalyst by a facile hydrolysis method. The presence of halogen was confirmed by a collection of ex situ and in situ characterizations, which rendered a more positive valence state of Sn in halogen-incorporated Sn catalyst as compared to unmodified Sn under cathodic potentials in CO2RR and therefore tuned the adsorption strength of the key intermediate (*OCHO) toward formate formation. As a result, the halogen-incorporated Sn catalyst exhibited greatly enhanced catalytic performance in electrochemical CO2RR to produce formate. 相似文献
3.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(26):7604-7607
Polymer electrolyte membranes employed in contemporary fuel cells severely limit device design and restrict catalyst choice, but are essential for preventing short‐circuiting reactions at unselective anode and cathode catalysts. Herein, we report that nickel sulfide Ni3S2 is a highly selective catalyst for the oxygen reduction reaction in the presence of 1.0 m formate. We combine this selective cathode with a carbon‐supported palladium (Pd/C) anode to establish a membrane‐free, room‐temperature formate fuel cell that operates under benign neutral pH conditions. Proof‐of‐concept cells display open circuit voltages of approximately 0.7 V and peak power values greater than 1 mW cm−2, significantly outperforming the identical device employing an unselective platinum (Pt) cathode. The work establishes the power of selective catalysis to enable versatile membrane‐free fuel cells. 相似文献
4.
Dehydrogenation of Formic Acid at Room Temperature: Boosting Palladium Nanoparticle Efficiency by Coupling with Pyridinic‐Nitrogen‐Doped Carbon 下载免费PDF全文
Dr. Qing‐Yuan Bi Jian‐Dong Lin Dr. Yong‐Mei Liu Prof. Dr. He‐Yong He Prof. Dr. Fu‐Qiang Huang Prof. Dr. Yong Cao 《Angewandte Chemie (International ed. in English)》2016,55(39):11849-11853
The use of formic acid (FA) to produce molecular H2 is a promising means of efficient energy storage in a fuel‐cell‐based hydrogen economy. To date, there has been a lack of heterogeneous catalyst systems that are sufficiently active, selective, and stable for clean H2 production by FA decomposition at room temperature. For the first time, we report that flexible pyridinic‐N‐doped carbon hybrids as support materials can significantly boost the efficiency of palladium nanoparticle for H2 generation; this is due to prominent surface electronic modulation. Under mild conditions, the optimized engineered Pd/CN0.25 catalyst exhibited high performance in both FA dehydrogenation (achieving almost full conversion, and a turnover frequency of 5530 h?1 at 25 °C) and the reversible process of CO2 hydrogenation into FA. This system can lead to a full carbon‐neutral energy cycle. 相似文献
5.
Dr. Junshan Li Ruilin Wei Xiang Wang Yong Zuo Xu Han Prof. Jordi Arbiol Prof. Jordi Llorca Prof. Yaoyue Yang Prof. Andreu Cabot Prof. Chunhua Cui 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(47):21012-21016
A methanol economy will be favored by the availability of low-cost catalysts able to selectively oxidize methanol to formate. This selective oxidation would allow extraction of the largest part of the fuel energy while concurrently producing a chemical with even higher commercial value than the fuel itself. Herein, we present a highly active methanol electrooxidation catalyst based on abundant elements and with an optimized structure to simultaneously maximize interaction with the electrolyte and mobility of charge carriers. In situ infrared spectroscopy combined with nuclear magnetic resonance spectroscopy showed that branched nickel carbide particles are the first catalyst determined to have nearly 100 % electrochemical conversion of methanol to formate without generating detectable CO2 as a byproduct. Electrochemical kinetics analysis revealed the optimized reaction conditions and the electrode delivered excellent activities. This work provides a straightforward and cost-efficient way for the conversion of organic small molecules and the first direct evidence of a selective formate reaction pathway. 相似文献
6.
Peilin Deng Fan Yang Zhitong Wang Shenghua Chen Yinzheng Zhou Shahid Zaman Bao Yu Xia 《Angewandte Chemie (International ed. in English)》2020,59(27):10807-10813
Carbon dioxide (CO2) conversion is promising in alleviating the excessive CO2 level and simultaneously producing valuables. This work reports the preparation of carbon nanorods encapsulated bismuth oxides for the efficient CO2 electroconversion toward formate production. This resultant catalyst exhibits a small onset potential of ?0.28 V vs. RHE and partial current density of over 200 mA cm?2 with a stable and high Faradaic efficiency of 93 % for formate generation in a flow cell configuration. Electrochemical results demonstrate the synergistic effect in the Bi2O3@C promotes the rapid and selective CO2 reduction in which the Bi2O3 is beneficial for improving the reaction kinetics and formate selectivity, while the carbon matrix would be helpful for enhancing the activity and current density of formate production. This work provides effective bismuth‐based MOF derivatives for efficient formate production and offers insights in promoting practical CO2 conversion technology. 相似文献
7.
Oxidative homocoupling of arylboronic acids catalyzed by a 4‐aminoantipyrine–Pd(II)complex 下载免费PDF全文
Claudia Araceli Contreras‐Celedón José Arturo Rincón‐Medina Darío Mendoza‐Rayo Luis Chacón‐García 《应用有机金属化学》2015,29(7):439-442
A one‐step synthesis of symmetric biaryls is reported under very mild conditions via the homocoupling reaction of substituted arylboronic acids using an air‐ and moisture‐stable 4‐aminoantipyrine–Pd(II) complex as catalyst. The reaction is conducted at a low catalyst loading of 0.1 mol% at room temperature in methanol in the presence of K2CO3 as the base and KMnO4 as the oxidant. The catalytic methodology is shown to be compatible with diverse functional groups and affords the desired biphenyls in good to excellent yields. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
8.
Binbin Yang Prof. Ran Ran Yijun Zhong Dr. Chao Su Prof. Moses O. Tadé Prof. Zongping Shao 《Angewandte Chemie (International ed. in English)》2015,54(12):3722-3725
We report a carbon–air battery for power generation based on a solid‐oxide fuel cell (SOFC) integrated with a ceramic CO2‐permeable membrane. An anode‐supported tubular SOFC functioned as a carbon fuel container as well as an electrochemical device for power generation, while a high‐temperature CO2‐permeable membrane composed of a CO32? mixture and an O2? conducting phase (Sm0.2Ce0.8O1.9) was integrated for in situ separation of CO2 (electrochemical product) from the anode chamber, delivering high fuel‐utilization efficiency. After modifying the carbon fuel with a reverse Boudouard reaction catalyst to promote the in situ gasification of carbon to CO, an attractive peak power density of 279.3 mW cm?2 was achieved for the battery at 850 °C, and a small stack composed of two batteries can be operated continuously for 200 min. This work provides a novel type of electrochemical energy device that has a wide range of application potentials. 相似文献
9.
Jinfa Chang Dr. Ligang Feng Prof. Dr. Changpeng Liu Prof. Dr. Wei Xing Prof. Dr. Xile Hu 《Angewandte Chemie (International ed. in English)》2014,53(1):122-126
The direct formic acid fuel cell is an emerging energy conversion device for which palladium is considered as the state‐of‐the‐art anode catalyst. In this communication, we show that the activity and stability of palladium for formic acid oxidation can be significantly enhanced using nickel phosphide (Ni2P) nanoparticles as a cocatalyst. X‐ray photoelectron spectroscopy (XPS) reveals a strong electronic interaction between Ni2P and Pd. A direct formic acid fuel cell incorporating the best Pd–Ni2P anode catalyst exhibits a power density of 550 mW cm?2, which is 3.5 times of that of an analogous device using a commercial Pd anode catalyst. 相似文献
10.
A heterometal (Pd–Pb) organic framework: synthesis,structure and heterogeneous catalytic application
A heterometallic organic framework {Pb[Pd(bpydc)Cl2]DMF}n ( 1 ) (H2bpydc = 2,2′‐bipyridine‐5,5′‐dicarboxylic acid) was synthesized via a one‐pot solvothermal method and characterized using thermogravimetric analysis, X‐ray photoelectron spectroscopy as well as powder and single‐crystal X‐ray diffraction. The crystal structure of 1 indicates that, in metalloligand Pd(bpydc)Cl2, every Pd atom adopts a square planar coordination mode with two chloride ions and two nitrogen atoms from bpydc, and the carboxyl groups of Pd(bpydc)Cl2 connect Pb atoms to form a one‐dimensional chain along the crystallographic a‐axis, which is interlinked via metalloligands to form a two‐dimensional layer structure. This complex is highly active, stable and recyclable as a catalyst for the Suzuki–Miyaura and Heck reactions of a wide range of aryl halides including electron‐rich and electron‐poor aryl iodides/bromides, affording the corresponding products in good to excellent yields. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
11.
Scott J. Folkman Jesús Gonzlez-Cobos Stefano Giancola Irene Snchez-Molina Jos Ramn Galn-Mascars 《Molecules (Basel, Switzerland)》2021,26(16)
Energy production and consumption without the use of fossil fuels are amongst the biggest challenges currently facing humankind and the scientific community. Huge efforts have been invested in creating technologies that enable closed carbon or carbon neutral fuel cycles, limiting CO2 emissions into the atmosphere. Formic acid/formate (FA) has attracted intense interest as a liquid fuel over the last half century, giving rise to a plethora of studies on catalysts for its efficient electrocatalytic oxidation for usage in fuel cells. However, new catalysts and catalytic systems are often difficult to compare because of the variability in conditions and catalyst parameters examined. In this review, we discuss the extensive literature on FA electrooxidation using platinum, palladium and non-platinum group metal-based catalysts, the conditions typically employed in formate electrooxidation and the main electrochemical parameters for the comparison of anodic electrocatalysts to be applied in a FA fuel cell. We focused on the electrocatalytic performance in terms of onset potential and peak current density obtained during cyclic voltammetry measurements and on catalyst stability. Moreover, we handpicked a list of the most relevant examples that can be used for benchmarking and referencing future developments in the field. 相似文献
12.
Hongwen Zhang Jintao Ming Jiwu Zhao Quan Gu Chao Xu Zhengxin Ding Rusheng Yuan Zizhong Zhang Huaxiang Lin Xuxu Wang Jinlin Long 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(23):7800-7804
An artificial photosynthetic (APS) system consisting of a photoanodic semiconductor that harvests solar photons to split H2O, a Ni‐SNG cathodic catalyst for the dark reaction of CO2 reduction in a CO2‐saturated NaHCO3 solution, and a proton‐conducting membrane enabled syngas production from CO2 and H2O with solar‐to‐syngas energy‐conversion efficiency of up to 13.6 %. The syngas CO/H2 ratio was tunable between 1:2 and 5:1. Integration of the APS system with photovoltaic cells led to an impressive overall quantum efficiency of 6.29 % for syngas production. The largest turnover frequency of 529.5 h?1 was recorded with a photoanodic N‐TiO2 nanorod array for highly stable CO production. The CO‐evolution rate reached a maximum of 154.9 mmol g?1 h?1 in the dark compartment of the APS cell. Scanning electrochemical–atomic force microscopy showed the localization of electrons on the single‐nickel‐atom sites of the Ni‐SNG catalyst, thus confirming that the multielectron reduction of CO2 to CO was kinetically favored. 相似文献
13.
Yumeng Liu Dong Tian Akash N. Biswas Zhenhua Xie Sooyeon Hwang Ji Hoon Lee Hong Meng Jingguang G. Chen 《Angewandte Chemie (International ed. in English)》2020,59(28):11345-11348
The electrochemical carbon dioxide reduction reaction (CO2RR) to produce synthesis gas (syngas) with tunable CO/H2 ratios has been studied by supporting Pd catalysts on transition metal nitride (TMN) substrates. Combining experimental measurements and density functional theory (DFT) calculations, Pd‐modified niobium nitride (Pd/NbN) is found to generate much higher CO and H2 partial current densities and greater CO Faradaic efficiency than Pd‐modified vanadium nitride (Pd/VN) and commercial Pd/C catalysts. In‐situ X‐ray diffraction identifies the formation of PdH in Pd/NbN and Pd/C under CO2RR conditions, whereas the Pd in Pd/VN is not fully transformed into the active PdH phase. DFT calculations show that the stabilized *HOCO and weakened *CO intermediates on PdH/NbN are critical to achieving higher CO2RR activity. This work suggests that NbN is a promising substrate to modify Pd, resulting in an enhanced electrochemical conversion of CO2 to syngas with a potential reduction in precious metal loading. 相似文献
14.
Peilin Deng Fan Yang Zhitong Wang Shenghua Chen Yinzheng Zhou Shahid Zaman Prof. Dr. Bao Yu Xia 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(27):10899-10905
Carbon dioxide (CO2) conversion is promising in alleviating the excessive CO2 level and simultaneously producing valuables. This work reports the preparation of carbon nanorods encapsulated bismuth oxides for the efficient CO2 electroconversion toward formate production. This resultant catalyst exhibits a small onset potential of −0.28 V vs. RHE and partial current density of over 200 mA cm−2 with a stable and high Faradaic efficiency of 93 % for formate generation in a flow cell configuration. Electrochemical results demonstrate the synergistic effect in the Bi2O3@C promotes the rapid and selective CO2 reduction in which the Bi2O3 is beneficial for improving the reaction kinetics and formate selectivity, while the carbon matrix would be helpful for enhancing the activity and current density of formate production. This work provides effective bismuth-based MOF derivatives for efficient formate production and offers insights in promoting practical CO2 conversion technology. 相似文献
15.
Da Hye Won Hyeyoung Shin Jaekang Koh Jaehoon Chung Hee Sang Lee Prof. Hyungjun Kim Prof. Seong Ihl Woo 《Angewandte Chemie (International ed. in English)》2016,55(32):9297-9300
Electrocatalytic CO2 conversion into fuel is a prospective strategy for the sustainable energy production. However, still many parts of the catalyst such as low catalytic activity, selectivity, and stability are challenging. Herein, a hierarchical hexagonal Zn catalyst showed highly efficient and, more importantly, stable performance as an electrocatalyst for selectively producing CO. Moreover, we found that its high selectivity for CO is attributed to morphology. In electrochemical analysis, Zn (101) facet is favorable to CO formation whereas Zn (002) facet favors the H2 evolution during CO2 electrolysis. Indeed, DFT calculations showed that (101) facet lowers a reduction potential for CO2 to CO by more effectively stabilizing a .COOH intermediate than (002) facet. This further suggests that tuning the crystal structure to control (101)/(002) facet ratio of Zn can be considered as a key design principle to achieve a desirable product from Zn catalyst. 相似文献
16.
Da Hye Won Hyeyoung Shin Jaekang Koh Jaehoon Chung Hee Sang Lee Hyungjun Kim Seong Ihl Woo 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(32):9443-9446
Electrocatalytic CO2 conversion into fuel is a prospective strategy for the sustainable energy production. However, still many parts of the catalyst such as low catalytic activity, selectivity, and stability are challenging. Herein, a hierarchical hexagonal Zn catalyst showed highly efficient and, more importantly, stable performance as an electrocatalyst for selectively producing CO. Moreover, we found that its high selectivity for CO is attributed to morphology. In electrochemical analysis, Zn (101) facet is favorable to CO formation whereas Zn (002) facet favors the H2 evolution during CO2 electrolysis. Indeed, DFT calculations showed that (101) facet lowers a reduction potential for CO2 to CO by more effectively stabilizing a .COOH intermediate than (002) facet. This further suggests that tuning the crystal structure to control (101)/(002) facet ratio of Zn can be considered as a key design principle to achieve a desirable product from Zn catalyst. 相似文献
17.
Wenhui He Itamar Liberman Illya Rozenberg Raya Ifraemov Idan Hod 《Angewandte Chemie (International ed. in English)》2020,59(21):8262-8269
Metal oxides or sulfides are considered to be one of the most promising CO2 reduction reaction (CO2RR) precatalysts, owing to their electrochemical conversion in situ into highly active electrocatalytic species. However, further improvement of the performance requires new tools to gain fine control over the composition of the active species and its structural features [e.g., grain boundaries (GBs) and undercoordinated sites (USs)], directly from a predesigned template material. Herein, we describe a novel electrochemically driven cation exchange (ED‐CE) method that enables the conversion of a predesigned CoS2 template into a CO2RR catalyst, Cu2S. By means of ED‐CE, the final Cu2S catalyst inherits the original 3 D morphology of CoS2, and preserves its high density of GBs. Additionally, the catalyst's phase structure, composition, and density of USs were precisely tuned, thus enabling rational design of active CO2RR sites. The obtained Cu2S catalyst achieved a CO2‐to‐formate Faradaic efficiency of over 87 % and a record high activity (among reported Cu‐based catalysts). Hence, this study opens the way for utilization of ED‐CE reactions to design advanced electrocatalysts. 相似文献
18.
Wajdi I. AlSadat Lynden A. Archer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(9):2658-2663
Conversion of low‐value, but thermodynamically stable chemical byproducts such as alkanes or CO2 to more valuable feedstocks is of broad‐based interest. These so‐called up‐conversion processes are expensive because they require energy‐intensive and catalytic interventions to drive reactions against thermodynamic gradients. Here we show that the nucleophilic characteristics of superoxides, generated galvanostatically in an Aluminum/O2 electrochemical cell, can be used in tandem with the intrinsic catalytic properties of an imidazolium/AlCl3 electrolyte to facilely upgrade alkanes (n‐decane), alkenes (1‐decene), and CO2 feedstocks. The aluminum/O2 electrochemical cell used to generate the superoxide intermediate is also reported to deliver large amounts of electrical energy and therefore offers a system for high‐energy density storage and for chemical up‐conversion of low‐value compounds. Chronopotentiometry, mass spectrometry and nuclear magnetic resonance were used to investigate the electrochemical features of the system and to analyze the discharge products. We find that even at room temperature, alkanes and alkenes are facilely oligomerized and isomerized at high conversions (>97 %), mimicking the traditionally produced refined products. Incorporating CO2 in the alkane feed leads to formation of esters and formates at moderate yields (21 %). 相似文献
19.
Bing Yan Nolan M. Concannon Jarrod D. Milshtein Prof. Dr. Fikile R. Brushett Prof. Dr. Yogesh Surendranath 《Angewandte Chemie (International ed. in English)》2017,56(26):7496-7499
Polymer electrolyte membranes employed in contemporary fuel cells severely limit device design and restrict catalyst choice, but are essential for preventing short-circuiting reactions at unselective anode and cathode catalysts. Herein, we report that nickel sulfide Ni3S2 is a highly selective catalyst for the oxygen reduction reaction in the presence of 1.0 m formate. We combine this selective cathode with a carbon-supported palladium (Pd/C) anode to establish a membrane-free, room-temperature formate fuel cell that operates under benign neutral pH conditions. Proof-of-concept cells display open circuit voltages of approximately 0.7 V and peak power values greater than 1 mW cm−2, significantly outperforming the identical device employing an unselective platinum (Pt) cathode. The work establishes the power of selective catalysis to enable versatile membrane-free fuel cells. 相似文献
20.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(33):9894-9898
Herein, we demonstrate that the intramolecular electron transfer within a single enzyme molecule is an important alternative pathway that can be harnessed to generate electricity. By decoupling the redox reactions within a single type of enzyme (for example, Trametes versicolor laccase), we harvested electricity efficiently from unconventional fuels including recalcitrant pollutants (for example, bisphenol A and hydroquinone) in a single‐laccase biofuel cell. The intramolecular electron‐harnessing concept was further demonstrated with other enzymes, including power generation during CO2 bioconversion to formate catalyzed by formate dehydrogenase from Candida boidinii . The novel single‐enzyme biofuel cell is shown to have potential for utilizing wastewater as a fuel as well as for generating energy while driving bioconversion of chemical feedstock from CO2. 相似文献