Electronic regulation of Ni single atom by confined Ni nanoparticles for fast and energy-efficient CO2 electroreduction

Abstract Electrocatalytic CO2 to CO conversion is approaching the industrial benchmark. Currently, Au electrodes show the best performance, whereas non-precious metal catalysts exhibit inferior activity. Here we show a densely populated Ni single-atom on nanoparticle catalyst (NiSA/NP) via direct solid-sate pyrolysis, where Ni nanoparticles donate electrons to Ni(i)-N-C sites via carbon nanotubes network, achieves a high CO current of 352 mA cm−2 at -0.55 V vs RHE in an alkaline flow cell. When coupled with a NiFe-based oxygen evolution anode into a zero-gap membrane electrolyser, it delivers an industrial-relevant CO current of 310 mA cm−2 at a low cell voltage of -2.3 V, corresponding to an overall energy efficiency of 57%. The superior CO2 electroreduction performance is attributed to the enhanced adsorption of key intermediate COOH* on electron-rich Ni single atom, together with the dense active sites.

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Atomically dispersed Fe3+ sites catalyze efficient CO2 electroreduction to CO

Science ◽

10.1126/science.aaw7515 ◽

2019 ◽

Vol 364 (6445) ◽

pp. 1091-1094 ◽

Cited By ~ 284

Author(s):

Jun Gu ◽

Chia-Shuo Hsu ◽

Lichen Bai ◽

Hao Ming Chen ◽

Xile Hu

Keyword(s):

Active Sites ◽

Carbon Support ◽

Single Atom ◽

Electronic Coupling ◽

X Ray ◽

Precious Metal Catalysts ◽

Co2 Electroreduction ◽

X Ray Absorption ◽

Partial Current ◽

Modest Activity

Currently, the most active electrocatalysts for the conversion of CO2 to CO are gold-based nanomaterials, whereas non–precious metal catalysts have shown low to modest activity. Here, we report a catalyst of dispersed single-atom iron sites that produces CO at an overpotential as low as 80 millivolts. Partial current density reaches 94 milliamperes per square centimeter at an overpotential of 340 millivolts. Operando x-ray absorption spectroscopy revealed the active sites to be discrete Fe3+ ions, coordinated to pyrrolic nitrogen (N) atoms of the N-doped carbon support, that maintain their +3 oxidation state during electrocatalysis, probably through electronic coupling to the conductive carbon support. Electrochemical data suggest that the Fe3+ sites derive their superior activity from faster CO2 adsorption and weaker CO absorption than that of conventional Fe2+ sites.

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Discovery of main group single Sb–N4 active sites for CO2 electroreduction to formate with high efficiency

Energy & Environmental Science ◽

10.1039/d0ee01486a ◽

2020 ◽

Vol 13 (9) ◽

pp. 2856-2863 ◽

Cited By ~ 10

Author(s):

Zhuoli Jiang ◽

Tao Wang ◽

Jiajing Pei ◽

Huishan Shang ◽

Danni Zhou ◽

...

Keyword(s):

Active Sites ◽

High Efficiency ◽

Main Group ◽

Single Atom ◽

Carbon Nanosheets ◽

Co2 Electroreduction

We discover that an Sb single atom material consisting of Sb–N4 moieties anchored on N-doped carbon nanosheets can serve as a CO2RR catalyst to produce formate with high efficiency.

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Double-Atom Catalysts Provide a Molecular Platform for Oxygen Evolution

10.26434/chemrxiv.11341961.v1 ◽

2019 ◽

Author(s):

Lichen Bai ◽

Chia-Shuo Hsu ◽

Duncan Alexander ◽

Hao Ming Chen ◽

Xile Hu

Keyword(s):

Oxygen Evolution ◽

Active Sites ◽

Supported Catalysts ◽

Single Atom ◽

Bond Forming ◽

Co2 Electroreduction ◽

Anode Reaction ◽

X Ray Absorption ◽

General Synthesis

The oxygen evolution reaction (OER) is an essential anode reaction for the generation of solar and electric fuels through water splitting or CO2 electroreduction. Mixed metal oxides containing Co, Fe, or Ni prove to be the most promising OER electrocatalysts in alkaline medium. However, the active sites and reaction mechanisms of these catalysts are difficult to study due to their heterogeneous nature. Here we describe a general synthesis of Co, Fe, and Ni-containing double-atom catalysts from their single-atom precursors via in-situ electrochemical transformation. Atomic-resolution microscopy and operando X-ray absorption spectroscopy (XAS) reveal molecule-like bimetallic active sites for these supported catalysts. Based on electrokinetic and XAS data, we propose a complete catalytic cycle for each catalyst. These mechanisms follow a similar O-O bond forming step and all exhibit bimetallic cooperation. However, the mechanisms diverge in the site and source of OH- for O-O bond formation as well as the order of proton and electron transfer. Our work demonstrates double-atom catalysts as an attractive platform for fundamental studies of heterogeneous OER electrocatalysts.

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Boosting CO2 electroreduction to CO with abundant nickel single atom active sites

Inorganic Chemistry Frontiers ◽

10.1039/d1qi00126d ◽

2021 ◽

Author(s):

Wei-juan Wang ◽

Changsheng Cao ◽

Kaiwen Wang ◽

Tianhua Zhou

Keyword(s):

Active Sites ◽

Single Atom ◽

Ni Catalyst ◽

Faradaic Efficiency ◽

Co2 Electroreduction ◽

Facile Route

A facile route for a single-atom Ni catalyst (Ni–SAs–NC) with dense Ni–N4 active sites is reported; the as-prepared Ni–SAs–N4C shows a 98% faradaic efficiency (FE) at −0.65 V for CO generation.

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Double-Atom Catalysts Provide a Molecular Platform for Oxygen Evolution

10.26434/chemrxiv.11341961 ◽

2019 ◽

Author(s):

Lichen Bai ◽

Chia-Shuo Hsu ◽

Duncan Alexander ◽

Hao Ming Chen ◽

Xile Hu

Keyword(s):

Oxygen Evolution ◽

Active Sites ◽

Supported Catalysts ◽

Single Atom ◽

Bond Forming ◽

Co2 Electroreduction ◽

Anode Reaction ◽

X Ray Absorption ◽

General Synthesis

The oxygen evolution reaction (OER) is an essential anode reaction for the generation of solar and electric fuels through water splitting or CO2 electroreduction. Mixed metal oxides containing Co, Fe, or Ni prove to be the most promising OER electrocatalysts in alkaline medium. However, the active sites and reaction mechanisms of these catalysts are difficult to study due to their heterogeneous nature. Here we describe a general synthesis of Co, Fe, and Ni-containing double-atom catalysts from their single-atom precursors via in-situ electrochemical transformation. Atomic-resolution microscopy and operando X-ray absorption spectroscopy (XAS) reveal molecule-like bimetallic active sites for these supported catalysts. Based on electrokinetic and XAS data, we propose a complete catalytic cycle for each catalyst. These mechanisms follow a similar O-O bond forming step and all exhibit bimetallic cooperation. However, the mechanisms diverge in the site and source of OH- for O-O bond formation as well as the order of proton and electron transfer. Our work demonstrates double-atom catalysts as an attractive platform for fundamental studies of heterogeneous OER electrocatalysts.

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Operando evidence of Cu+ stabilization via a single-atom modifier for CO2 electroreduction

Journal of Materials Chemistry A ◽

10.1039/d0ta08369k ◽

2020 ◽

Vol 8 (48) ◽

pp. 25970-25977 ◽

Cited By ~ 1

Author(s):

Wei Zhang ◽

Peng He ◽

Chao Wang ◽

Tao Ding ◽

Tao Chen ◽

...

Keyword(s):

Single Atom ◽

Stable Intermediate ◽

Co Conversion ◽

Co2 Electroreduction

Single-atom Sn modified Cu2O nanosheets with stable intermediate Cu+ species for efficient CO2-to-CO conversion proved by operando XAFS.

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Engineering Ag–Nx Single-Atom Sites on Porous Concave N-Doped Carbon for Boosting CO2 Electroreduction

ACS Applied Materials & Interfaces ◽

10.1021/acsami.1c03638 ◽

2021 ◽

Author(s):

Rui Sui ◽

Jiajing Pei ◽

Jinjie Fang ◽

Xuejiang Zhang ◽

Yufeng Zhang ◽

...

Keyword(s):

Single Atom ◽

Co2 Electroreduction

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Insights on forming N,O-coordinated Cu single-atom catalysts for electrochemical reduction CO2 to methane

Nature Communications ◽

10.1038/s41467-020-20769-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Yanming Cai ◽

Jiaju Fu ◽

Yang Zhou ◽

Yu-Chung Chang ◽

Qianhao Min ◽

...

Keyword(s):

Energy Barrier ◽

Active Sites ◽

Theoretical Calculations ◽

High Energy ◽

Single Atom ◽

Faradaic Efficiency ◽

High Energy Barrier ◽

Catalytic Sites ◽

Electron Reduction ◽

First Time

AbstractSingle-atom catalysts (SACs) are promising candidates to catalyze electrochemical CO2 reduction (ECR) due to maximized atomic utilization. However, products are usually limited to CO instead of hydrocarbons or oxygenates due to unfavorable high energy barrier for further electron transfer on synthesized single atom catalytic sites. Here we report a novel partial-carbonization strategy to modify the electronic structures of center atoms on SACs for lowering the overall endothermic energy of key intermediates. A carbon-dots-based SAC margined with unique CuN2O2 sites was synthesized for the first time. The introduction of oxygen ligands brings remarkably high Faradaic efficiency (78%) and selectivity (99% of ECR products) for electrochemical converting CO2 to CH4 with current density of 40 mA·cm-2 in aqueous electrolytes, surpassing most reported SACs which stop at two-electron reduction. Theoretical calculations further revealed that the high selectivity and activity on CuN2O2 active sites are due to the proper elevated CH4 and H2 energy barrier and fine-tuned electronic structure of Cu active sites.

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Double Boosting Single Atom Fe-N4 Sites for High Efficiency O2 and CO2 Electroreduction

Carbon ◽

10.1016/j.carbon.2021.05.038 ◽

2021 ◽

Author(s):

Huijuan Yang ◽

Xingpu Wang ◽

ShengBao Wang ◽

Pengyang Zhang ◽

Chi Xiao ◽

...

Keyword(s):

High Efficiency ◽

Single Atom ◽

Co2 Electroreduction

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