Tailoring Acidic Oxygen Reduction Selectivity on Single-Atom Catalysts via Modification of First and Second Coordination Spheres

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(20), С. 7819 - 7827

Опубликована: Май 13, 2021

Product selectivity in multielectron electrocatalytic reactions is crucial to energy conversion efficiency and chemical production. However, a present practical drawback the limited understanding of actual catalytic active sites. Here, using as prototype single-atom catalysts (SACs) acidic oxygen reduction reaction (ORR), we report structure–property relationship show for first time that molecular-level local structure, including second coordination spheres (CSs), rather than individual atoms, synergistically determines response. ORR on Co-SACs can be tailored from four-electron two-electron pathway by modifying (N or/and O coordination) (C–O–C groups) CSs. Using combined theoretical predictions experiments, X-ray absorption fine structure analyses situ infrared spectroscopy, confirm unique change originates structure-dependent shift sites center Co atom O-adjacent C atom. We this optimizes electronic *OOH adsorption behavior give "best" activity >95% H2O2 electrosynthesis.

Язык: Английский

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Coordination Engineering of Single‐Atom Catalysts for the Oxygen Reduction Reaction: A Review

Advanced Energy Materials, Год журнала: 2020, Номер 11(3)

Опубликована: Ноя. 30, 2020

Abstract Future renewable energy supplies and a sustainable environment rely on many important catalytic processes. Single‐atom catalysts (SACs) are attractive because of their maximum atom utilization efficiency, tunable electronic structures, outstanding performance. Of particular note, transition‐metal SACs exhibit excellent activity selectivity for the oxygen reduction reaction (ORR)—an half in fuel cells metal–air batteries as well portable hydrogen peroxide (H 2 O ) production. Although considerable efforts have been made synthesis ORR, regulation coordination environments thus structures still pose big challenge. In this review, strategies manipulating classified into three categories, including center metal atoms, manipulation surrounding connecting to atom, modification geometric configuration support. Finally, some issues regarding future development ORR raised possible solutions proposed.

Язык: Английский

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Identification of the Highly Active Co–N₄ Coordination Motif for Selective Oxygen Reduction to Hydrogen Peroxide

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(32), С. 14505 - 14516

Опубликована: Авг. 3, 2022

Electrosynthesis of hydrogen peroxide (H

Язык: Английский

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Honeycomb Carbon Nanofibers: A Superhydrophilic O₂‐Entrapping Electrocatalyst Enables Ultrahigh Mass Activity for the Two‐Electron Oxygen Reduction Reaction

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(19), С. 10583 - 10587

Опубликована: Фев. 25, 2021

Abstract Electrocatalytic two‐electron oxygen reduction has emerged as a promising alternative to the energy‐ and waste‐intensive anthraquinone process for distributed H 2 O production. This process, however, suffers from strong competition four‐electron pathway leading low selectivity. Herein, we report using superhydrophilic ‐entrapping electrocatalyst enable superb electrocatalysis. The honeycomb carbon nanofibers (HCNFs) are robust capable of achieving high selectivity 97.3 %, much higher than that its solid nanofiber counterpart. Impressively, this catalyst achieves an ultrahigh mass activity up 220 A g −1 , surpassing all other catalysts reaction. porous skeleton with rich oxygenated functional groups facilitates efficient electron transfer better wetting by electrolyte, interconnected cavities allow more effective entrapping gas bubbles. catalytic mechanism is further revealed in situ Raman analysis density theory calculations.

Язык: Английский

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Noble-metal single-atoms in thermocatalysis, electrocatalysis, and photocatalysis

Energy & Environmental Science, Год журнала: 2021, Номер 14(5), С. 2954 - 3009

Опубликована: Янв. 1, 2021

This review summarizes the recent advances about noble-metal single-atom catalysts in thermocatalysis, electrocatalysis, and photocatalysis.

Язык: Английский

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Carbon‐Based Electrocatalysts for Efficient Hydrogen Peroxide Production

Advanced Materials, Год журнала: 2021, Номер 33(49)

Опубликована: Сен. 24, 2021

Abstract Hydrogen peroxide (H 2 O ) is an environment‐friendly and efficient oxidant with a wide range of applications in different industries. Recently, the production hydrogen through direct electrosynthesis has attracted widespread research attention, emerged as most promising method to replace traditional energy‐intensive multi‐step anthraquinone process. In ongoing efforts achieve highly large‐scale H , carbon‐based materials have been developed 2e − oxygen reduction reaction catalysts, benefits low cost, abundant availability, optimal performance. This review comprehensively introduces strategies for optimizing toward production, latest advances hybrid catalysts. The active sites influence coordination heteroatom doping on selectivity are extensively analyzed. particular, appropriate design functional groups understanding effect electrolyte pH expected further improve selective efficiency producing via reaction. Methods improving catalytic activity by interface engineering kinetics summarized. Finally, challenges catalysts face before they can be employed commercial‐scale identified, prospects designing novel electrochemical reactors proposed.

Язык: Английский

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Recent Advances in Electrochemical Oxygen Reduction to H₂O₂: Catalyst and Cell Design

ACS Energy Letters, Год журнала: 2020, Номер 5(6), С. 1881 - 1892

Опубликована: Май 8, 2020

Electrochemical production of H2O2 from O2 is a promising alternative to the energy-intensive anthraquinone process that currently used as an industry standard. Although most research on oxygen reduction reaction (ORR) has focused 4-electron pathway water relevant fuel cells, 2-electron ORR produce also significant commercial interest. The first half this Perspective deals with progress made in developing noble metal, carbon-based, and single-atom electrocatalysts highlights design strategies employed obtain high selectivity toward H2O2. second addresses challenges large-scale how results obtained using rotating ring disk electrode (RRDE) can be translated into commercially viable flow cells. This focuses catalysts cells will enable industrial-scale electrochemical production.

Язык: Английский

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Chemical Identification of Catalytically Active Sites on Oxygen‐doped Carbon Nanosheet to Decipher the High Activity for Electro‐synthesis Hydrogen Peroxide

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(30), С. 16607 - 16614

Опубликована: Май 13, 2021

Abstract Electrochemical production of hydrogen peroxide (H 2 O ) through two‐electron (2 e − oxygen reduction reaction (ORR) is an on‐site and clean route. Oxygen‐doped carbon materials with high ORR activity H selectivity have been considered as the promising catalysts, however, there still a lack direct experimental evidence to identify true active sites at complex surface. Herein, we propose chemical titration strategy decipher oxygen‐doped nanosheet (OCNS 900 catalyst for ORR. The OCNS exhibits outstanding performances onset potential 0.825 V (vs. RHE), mass 14.5 A g −1 0.75 RHE) rate 770 mmol h in flow cell, surpassing most reported catalysts. Through selective C=O, C−OH, COOH groups, found that C=O species contributed electrocatalytic were ORR, which corroborated by theoretical calculations.

Язык: Английский

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Main-group elements boost electrochemical nitrogen fixation

Chem, Год журнала: 2021, Номер 7(12), С. 3232 - 3255

Опубликована: Ноя. 9, 2021

Язык: Английский

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Approaching a high-rate and sustainable production of hydrogen peroxide: oxygen reduction on Co–N–C single-atom electrocatalysts in simulated seawater

Energy & Environmental Science, Год журнала: 2021, Номер 14(10), С. 5444 - 5456

Опубликована: Янв. 1, 2021

Sustainable production of H 2 O is boosted by oxygen reduction reaction on Co–N 5 sites in a flow cell simulated seawater.

Язык: Английский

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