MOF-Derived Co and Fe Species Loaded on N-Doped Carbon Networks as Efficient Oxygen Electrocatalysts for Zn-Air Batteries

Nano-Micro Letters, Год журнала: 2022, Номер 14(1)

Опубликована: Авг. 11, 2022

Searching for cheap, efficient, and stable oxygen electrocatalysts is vital to promote the practical performance of Zn-air batteries with high theoretic energy density. Herein, a series Co nanoparticles highly dispersed Fe loaded on N-doped porous carbon substrates are prepared through "double-solvent" method in situ doped metal-organic frameworks as precursors. The optimized catalysts exhibit excellent reduction evolution reaction. Furthermore, rechargeable designed demonstrate higher peak power density better cycling stability than those commercial Pt/C+RuO2. According structure characterizations electrochemical tests, interaction contributes superior electrocatalysis. In addition, large specific surface areas, structures interconnected three-dimensional networks also play important roles improving This work provides inspiration rational design advanced paves way application batteries.

Язык: Английский

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Ni single atoms anchored on N-doped carbon nanosheets as bifunctional electrocatalysts for Urea-assisted rechargeable Zn-air batteries

Applied Catalysis B Environment and Energy, Год журнала: 2022, Номер 310, С. 121352 - 121352

Опубликована: Март 30, 2022

Язык: Английский

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Bifunctional Single Atom Catalysts for Rechargeable Zinc–Air Batteries: From Dynamic Mechanism to Rational Design

Advanced Materials, Год журнала: 2023, Номер 35(35)

Опубликована: Июнь 7, 2023

Ever-growing demands for rechargeable zinc-air batteries (ZABs) call efficient bifunctional electrocatalysts. Among various electrocatalysts, single atom catalysts (SACs) have received increasing attention due to the merits of high utilization, structural tunability, and remarkable activity. Rational design SACs relies heavily on an in-depth understanding reaction mechanisms, especially dynamic evolution under electrochemical conditions. This requires a systematic study in mechanisms replace current trial error modes. Herein, fundamental oxygen reduction is first presented combining situ and/or operando characterizations theoretical calculations. By highlighting structure-performance relationships, rational regulation strategies are particularly proposed facilitate SACs. Furthermore, future perspectives challenges discussed. review provides thorough SACs, which expected pave avenue exploring optimum effective ZABs.

Язык: Английский

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Mutual Self-Regulation of d-Electrons of Single Atoms and Adjacent Nanoparticles for Bifunctional Oxygen Electrocatalysis and Rechargeable Zinc-Air Batteries

Nano-Micro Letters, Год журнала: 2023, Номер 15(1)

Опубликована: Фев. 11, 2023

Rechargeable zinc-air batteries (ZABs) are a promising energy conversion device, which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction (ORR) and evolution (OER). Herein, we fabricate range of bifunctional M-N-C (metal-nitrogen-carbon) catalysts containing M-Nx coordination sites M/MxC nanoparticles (M = Co, Fe, Cu) using new class γ-cyclodextrin (CD) based metal-organic framework the precursor. With two types active interacting with each other in catalysts, obtained Fe@C-FeNC Co@C-CoNC display superior alkaline ORR activity terms low half-wave (E1/2) potential (~ 0.917 0.906 V, respectively), higher than Cu@C-CuNC 0.829 V) commercial Pt/C 0.861 V). As electrocatalyst, exhibits best performance, showing ORR/OER overpotential (ΔE) ~ 0.732 is much lower that 0.831 1.411 V), well most robust reported date. Synchrotron X-ray absorption spectroscopy density functional theory simulations reveal strong electronic correlation between metallic Co atomic Co-N4 catalyst can increase d-electron near Fermi level thus effectively optimize adsorption/desorption intermediates ORR/OER, resulting an enhanced electrocatalytic performance. The Co@C-CoNC-based rechargeable ZAB exhibited maximum power 162.80 mW cm-2 at 270.30 mA cm-2, combination + RuO2 158.90 265.80 cm-2) catalysts. During galvanostatic discharge 10 delivered almost stable voltage 1.2 V for 140 h, signifying virtue excellent activity.

Язык: Английский

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Electrocatalytic Synthesis of Essential Amino Acids from Nitric Oxide Using Atomically Dispersed Fe on N‐doped Carbon

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(26)

Опубликована: Апрель 19, 2023

How to transfer industrial exhaust gases of nitrogen oxides into high-values product is significantly important and challenging. Herein, we demonstrate an innovative method for artificial synthesis essential α-amino acids from nitric oxide (NO) by reacting with α-keto through electrocatalytic process atomically dispersed Fe supported on N-doped carbon matrix (AD-Fe/NC) as the catalyst. A yield valine 32.1 μmol mgcat-1 delivered at -0.6 V vs. reversible hydrogen electrode, corresponding a selectivity 11.3 %. In situ X-ray absorption fine structure synchrotron radiation infrared spectroscopy analyses show that NO source converted hydroxylamine promptly nucleophilic attacked electrophilic center acid form oxime subsequent reductive hydrogenation occurred way amino acid. Over 6 kinds have been successfully synthesized gaseous can be also replaced liquid (NO3- ). Our findings not only provide creative converting high-valued products, which epoch-making significance towards acids, but benefit in deploying near-zero-emission technologies global environmental economic development.

Язык: Английский

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High‐Density Atomic Fe–N₄/C in Tubular, Biomass‐Derived, Nitrogen‐Rich Porous Carbon as Air‐Electrodes for Flexible Zn–Air Batteries

Advanced Functional Materials, Год журнала: 2023, Номер 33(20)

Опубликована: Фев. 22, 2023

Abstract Developing low‐cost single‐atom catalysts (SACs) with high‐density active sites for oxygen reduction/evolution reactions (ORR/OER) are desirable to promote the performance and application of metal–air batteries. Herein, Fe nanoparticles precisely regulated single atoms supported on waste biomass corn silk (CS) based porous carbon ORR OER. The distinct hierarchical structure hollow tube morphology critical boosting ORR/OER through exposing more accessible sites, providing facile electron conductivity, facilitating mass transfer reactant. Moreover, enhanced intrinsic activity is mainly ascribed high (4.3 wt.%) loading content in as‐synthesized catalyst.Moreover, ultra‐high N doping (10 can compensate insufficient OER conventional FeNC catalysts. When as‐prepared assembled as air‐electrodes flexible Zn–air batteries, they perform a peak power density 101 mW cm −2 , stable discharge–charge voltage gap 0.73 V >44 h, which shows great potential Zinc–air battery. This work provides an avenue transform renewable materials into bifunctional electrocatalysts structure.

Язык: Английский

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Atomically dispersed Ni activates adjacent Ce sites for enhanced electrocatalytic oxygen evolution activity

Science Advances, Год журнала: 2023, Номер 9(26)

Опубликована: Июнь 28, 2023

Manipulating the intrinsic activity of heterogeneous catalysts at atomic level is an effective strategy to improve electrocatalytic performances but remains challenging. Here, atomically dispersed Ni anchored on CeO2 particles entrenched peanut-shaped hollow nitrogen-doped carbon structures (a-Ni/CeO2@NC) rationally designed and synthesized. The as-prepared a-Ni/CeO2@NC catalyst exhibits substantially boosted greatly reduced overpotential for oxygen evolution reaction. Experimental theoretical results demonstrate that decoration isolated species over induces electronic coupling redistribution, thus resulting in activation adjacent Ce sites around atoms accelerated kinetics. This work provides a promising explore regulation improvement level, thereby improving activity.

Язык: Английский

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Terbium-induced cobalt valence-band narrowing boosts electrocatalytic oxygen reduction

Energy & Environmental Science, Год журнала: 2023, Номер 16(11), С. 5500 - 5512

Опубликована: Янв. 1, 2023

Tb 2 O 3 endows Co 3d with a narrow band and appropriate location via 3d–O 2p–Tb 4f gradient orbital coupling to efficiently enhance the oxygen reduction reaction.

Язык: Английский

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A Review of In-Situ Techniques for Probing Active Sites and Mechanisms of Electrocatalytic Oxygen Reduction Reactions

Nano-Micro Letters, Год журнала: 2022, Номер 15(1)

Опубликована: Дек. 29, 2022

Electrocatalytic oxygen reduction reaction (ORR) is one of the most important reactions in electrochemical energy technologies such as fuel cells and metal-O2/air batteries, etc. However, essential catalysts to overcome its slow kinetic always undergo a complex dynamic evolution actual catalytic process, concomitant intermediates products also occur continuous conversion reconstruction. This makes them difficult be accurately captured, making identification ORR active sites elucidation mechanisms difficult. Thus, it necessary use extensive in-situ characterization techniques proceed real-time monitoring catalyst structure state during ORR. work reviews major advances various characterize processes catalysts. Specifically, evolutions revealed directly by are systematically summarized, phase, valence, electronic transfer, coordination, spin states varies. In-situ revelation intermediate adsorption/desorption behavior, product nucleation, growth, reconstruction equally emphasized discussion. Other interference factors, well signal assignment with aid theoretical calculations, covered. Finally, some challenges prospects for future research process proposed.

Язык: Английский

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Dual-atom Co-Fe catalysts for oxygen reduction reaction

CHINESE JOURNAL OF CATALYSIS (CHINESE VERSION), Год журнала: 2023, Номер 46, С. 48 - 55

Опубликована: Фев. 23, 2023

Язык: Английский

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