Ni single-atom sites supported on carbon aerogel for highly efficient electroreduction of carbon dioxide with industrial current densities

eScience, Год журнала: 2022, Номер 2(3), С. 295 - 303

Опубликована: Апрель 6, 2022

Finding highly efficient electrocatalysts for the CO2 electroreduction reactions (CO2RR) that have high selectivity and appreciable current density to meet commercial application standards remains a challenge. Because their reduction potentials are similar of associated competitive hydrogen evolution reaction activation kinetics sluggish. Although single-atom catalysts (SACs) with atom efficiency one class promising candidates CO2RR produce CO, active sites supported on microporous carbons not fully exposed substrates thus lead low density. Carbon aerogels interconnected channels macropores can facilitate mass transport. But few reports describe utilizing them as supports anchor SACs electrocatalysis. Herein, N-doped carbon supporting Ni single atomic catalyst (denoted Ni-NCA-X, X ​= ​10, 20) were fabricated by pyrolyzing Ni/Zn bimetallic zeolitic imidazolate framework (Ni/Zn-ZIF-8)/carboxymethylcellulose composite gels. Owing abundant hierarchical micro-, meso-, adsorption, in optimal Ni-NCA-10 readily accessible electrolyte molecules achieved an industrial-level CO partial 226 ​mA ​cm−2, Faradaic 95.6% at −1.0 ​V vs. reversible electrode, large turnover frequency 271810 h−1 flow-cell reactor ​V. Such excellent performance makes rare state-of-the-art electrocatalyst CO2-to-CO conversion. This work provides effective strategy designing toward achieve industrial via anchoring aerogels.

Язык: Английский

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High‐Rate and Selective CO₂ Electrolysis to Ethylene via Metal–Organic‐Framework‐Augmented CO₂ Availability

Advanced Materials, Год журнала: 2022, Номер 34(51)

Опубликована: Окт. 17, 2022

High-rate conversion of carbon dioxide (CO2 ) to ethylene (C2 H4 in the CO2 reduction reaction RR) requires fine control over phase boundary gas diffusion electrode (GDE) overcome limit solubility aqueous electrolytes. Here, a metal-organic framework (MOF)-functionalized GDE design is presented, based on catalysts:MOFs:hydrophobic substrate materials layered architecture, that leads high-rate and selective C2 production flow cells membrane assembly (MEA) electrolyzers. It found using electroanalysis operando X-ray absorption spectroscopy (XAS), MOF-induced organic layers GDEs augment local concentration near active sites Cu catalysts. MOFs with different adsorption abilities are used, stacking ordering varied. While sputtering poly(tetrafluoroethylene) (PTFE) (Cu/PTFE) exhibits 43% Faradaic efficiency (FE) at current density 200 mA cm-2 cell, 49% FE 1 A achieved MOF-augmented RR. further evaluated an MEA electrolyzer, achieving partial 220 for RR 121 monoxide (CORR), representing 2.7-fold 15-fold improvement rate, compared those obtained bare Cu/PTFE.

Язык: Английский

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Keeping sight of copper in single-atom catalysts for electrochemical carbon dioxide reduction

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Апрель 27, 2022

Carbon dioxide can be electrochemically converted into valuable multi-carbon products using Cu-based single-atom catalysts. However, transient cluster formation, which is undetectable ex-situ techniques, may responsible for C2+ products. Here we discuss these observations to highlight the need operando characterisation when defining active sites. single atom catalysts convert CO2 products, however, assignment of sites needs great caution. In this comment, authors Cu formation as and emphasise in mechanistic study.

Язык: Английский

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Tailoring Coordination Microenvironment of Cu(I) in Metal–Organic Frameworks for Enhancing Electroreduction of CO₂to CH₄

Advanced Functional Materials, Год журнала: 2022, Номер 32(36)

Опубликована: Июнь 29, 2022

Abstract The coordination microenvironment of metal active sites in metal–organic frameworks (MOFs) plays a crucial role its performance for electrochemical CO 2 reduction reaction (CO RR). However, it remains challenge to clarify the structure–performance relationship RR catalyzed by MOFs. Herein, series MOFs with different microenvironments Cu(I) (CuCl, CuBr, and CuI) evaluate their performances is synthesized. With increasing radius halogen atom, adsorption capacity increases d‐band center Cu positively shifts Fermi level, leading enhance selectivity CH 4 conversion. CuI gives highest total Faradaic efficiency (FE) 83.2%, FE up 57.2% partial current density 60.7 mA cm −2 at −1.08 V versus reversible hydrogen electrode. Theoretical calculations reveal that shifted site contributes reduced formation energies *CH O 3 intermediates, which potential‐determining step thus facilitates electrocatalytic . This study opens new avenue studying between electroreduction

Язык: Английский

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Flexible Cuprous Triazolate Frameworks as Highly Stable and Efficient Electrocatalysts for CO₂ Reduction with Tunable C₂H₄/CH₄ Selectivity

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(28)

Опубликована: Май 5, 2022

Cu-based metal-organic frameworks have attracted much attention for electrocatalytic CO2 reduction, but they are generally instable and difficult to control the product selectivity. We report flexible Cu(I) triazolate as efficient, stable, tunable electrocatalysts reduction C2 H4 /CH4 . By changing size of ligand side groups, selectivity ratio can be gradually tuned inversed from 11.8 : 1 2.6, giving , CH4 hydrocarbon selectivities up 51 %, 56 77 respectively. After long-term electrocatalysis, retain structures/morphologies without formation inorganic species. Computational simulations showed that coordination geometry changed triangular tetrahedral bind reaction intermediates, two adjacent cooperated C-C coupling form Importantly, groups controlled catalyst flexibility by steric hindrance mechanism, pathway is more sensitive than one.

Язык: Английский

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