Defect‐Rich Porous Palladium Metallene for Enhanced Alkaline Oxygen Reduction Electrocatalysis

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(21), С. 12027 - 12031

Опубликована: Фев. 9, 2021

Abstract Metallene with fantastic physicochemical properties is considered as a potential candidate for oxygen reduction reaction (ORR). Controlling the morphology and structure of metallene can provide great opportunity to improve its catalytic performance. Herein, defect‐rich ultrathin porous Pd (a sub‐nanometer curved metal nanosheet) developed by facile wet‐chemistry strategy efficient stable ORR electrocatalysis in alkaline electrolyte. The provides abundant highly active sites vacancy defects, showing superior activity 0.892 A mg −1 at 0.9 V vs. reversible hydrogen electrode. mass 5.1 16.8 times higher than those commercial Pt/C Pd/C, respectively, maintains well after 5000 cycles. strain effect tunable electronic derived from nanosheet contribute excellent performance optimization binding ability on Pd. may open an avenue design other materials various fields.

Язык: Английский

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In Situ Fragmented Bismuth Nanoparticles for Electrocatalytic Nitrogen Reduction

Advanced Energy Materials, Год журнала: 2020, Номер 10(33)

Опубликована: Июль 21, 2020

Abstract The electrochemical nitrogen reduction reaction (NRR) is a promising alternative to the energy‐intensive Haber–Bosch process for ammonia synthesis. Among possible electrocatalysts, bismuth‐based materials have shown unique NRR properties due their electronic structures and poor hydrogen evolution activity. However, identification of active sites mechanism still difficult structural chemical changes under potentials. Herein, in situ Raman spectroscopy, complemented by electron microscopy, employed investigate transformation Bi species during NRR. Nanorod‐like metal–organic frameworks are reduced fragment into densely contacted 0 nanoparticles applied fragmented exhibit excellent performance both neutral acidic electrolytes, with an yield 3.25 ± .08 µg cm −2 h −1 at −0.7 V versus reversible electrode Faradaic efficiency 12.11 0.84% −0.6 0.10 m Na 2 SO 4 . Online differential mass spectrometry detects production NH 3 N H NRR, suggesting pathway through two‐step decomposition. This work highlights importance monitoring optimizing geometric electrocatalysts conditions.

Язык: Английский

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Recent advances in strategies for highly selective electrocatalytic N2 reduction toward ambient NH3 synthesis

Current Opinion in Electrochemistry, Год журнала: 2021, Номер 29, С. 100766 - 100766

Опубликована: Май 15, 2021

Язык: Английский

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Realizing a Not-Strong-Not-Weak Polarization Electric Field in Single-Atom Catalysts Sandwiched by Boron Nitride and Graphene Sheets for Efficient Nitrogen Fixation

Journal of the American Chemical Society, Год журнала: 2020, Номер 142(45), С. 19308 - 19315

Опубликована: Окт. 27, 2020

Developing efficient single-atom catalysts (SACs) for nitrogen fixation is of great importance while remaining a challenge. The lack an effective strategy to control the polarization electric field SACs limits their activity and selectivity. Here, using first-principles calculations, we report that single transition metal (TM) atom sandwiched between hexagonal boron nitride (h-BN) graphene sheets (namely, BN/TM/G) acts as SAC electrochemical reduction reaction (NRR). These sandwich structures realize stable tunable interfacial fields enable TM donate electrons neighboring B active site. As result, partially occupied pz orbital can form B-to-N π-back bonding with antibonding state N2, thus weakening N≡N bond. not-strong-not-weak on h-BN surface further promotes N2 adsorption activation. NRR catalytic BN/TM/G system highly correlated degree positively polarized charges atom. In particular, BN/Ti/G BN/V/G are identified promising high stability, offering excellent energy efficiency suppression competing hydrogen evolution reaction.

Язык: Английский

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Spontaneous Atomic Ruthenium Doping in Mo₂CT_X MXene Defects Enhances Electrocatalytic Activity for the Nitrogen Reduction Reaction

Advanced Energy Materials, Год журнала: 2020, Номер 10(25)

Опубликована: Май 19, 2020

Abstract The electrochemical nitrogen reduction reaction (NRR) process usually suffers extremely low Faradaic efficiency and ammonia yields due to sluggish NN dissociation. Herein, single‐atomic ruthenium modified Mo 2 CT X MXene nanosheets as an efficient electrocatalyst for fixation at ambient conditions are reported. catalyst achieves a of 25.77% yield rate 40.57 µg h −1 mg ‐0.3 V versus the reversible hydrogen electrode in 0.5 m K SO 4 solution. Operando X‐ray absorption spectroscopy studies density functional theory calculations reveal that Ru anchored on act important electron back‐donation centers N activation, which can not only promote adsorption activation behavior catalyst, but also lower thermodynamic energy barrier first hydrogenation step. This work opens up promising avenue manipulate catalytic performance electrocatalysts utilizing atomic‐level engineering strategy.

Язык: Английский

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