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

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.

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

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.

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

2020 ◽  
Vol 13 (9) ◽  
pp. 2856-2863 ◽  
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.

scholarly journals Atomically dispersed Fe3+ sites catalyze efficient CO2 electroreduction to CO

Science ◽  
2019 ◽  
Vol 364 (6445) ◽  
pp. 1091-1094 ◽  
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.

scholarly journals Double-Atom Catalysts Provide a Molecular Platform for Oxygen Evolution

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.

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

2021 ◽  
Author(s):  
Wenhao Ren ◽  
Xin Tan ◽  
Chen Jia ◽  
Anna Krammer ◽  
Qian Sun ◽  
...  
Keyword(s):  
Active Sites ◽  
Cell Voltage ◽  
Single Atom ◽  
Ni Nanoparticles ◽  
Precious Metal Catalysts ◽  
Co Conversion ◽  
Co2 Electroreduction ◽  
Enhanced Adsorption ◽  
Direct Solid ◽  
Nanoparticle Catalyst

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.

scholarly journals Double-Atom Catalysts Provide a Molecular Platform for Oxygen Evolution

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.

scholarly journals Folic Acid Self-Assembly Enabling Manganese Single-Atom Electrocatalyst for Selective Nitrogen Reduction to Ammonia

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Xuewan Wang ◽  
Dan Wu ◽  
Suyun Liu ◽  
Jiujun Zhang ◽  
Xian-Zhu Fu ◽  
...  
Keyword(s):  
Folic Acid ◽  
Self Assembly ◽  
Active Sites ◽  
Density Functional ◽  
Carbon Matrix ◽  
Single Atom ◽  
Synthesis Process ◽  
Ambient Conditions ◽  
Hydrogen Electrode ◽  
Faradaic Efficiency

AbstractEfficient and robust single-atom catalysts (SACs) based on cheap and earth-abundant elements are highly desirable for electrochemical reduction of nitrogen to ammonia (NRR) under ambient conditions. Herein, for the first time, a Mn–N–C SAC consisting of isolated manganese atomic sites on ultrathin carbon nanosheets is developed via a template-free folic acid self-assembly strategy. The spontaneous molecular partial dissociation enables a facile fabrication process without being plagued by metal atom aggregation. Thanks to well-exposed atomic Mn active sites anchored on two-dimensional conductive carbon matrix, the catalyst exhibits excellent activity for NRR with high activity and selectivity, achieving a high Faradaic efficiency of 32.02% for ammonia synthesis at  − 0.45 V versus reversible hydrogen electrode. Density functional theory calculations unveil the crucial role of atomic Mn sites in promoting N2 adsorption, activation and selective reduction to NH3 by the distal mechanism. This work provides a simple synthesis process for Mn–N–C SAC and a good platform for understanding the structure-activity relationship of atomic Mn sites. Graphic Abstract

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

2021 ◽  
Author(s):  
Wenhao Ren ◽  
Xin Tan ◽  
Chen Jia ◽  
Anna Krammer ◽  
Qian Sun ◽  
...  
Keyword(s):  
Active Sites ◽  
Cell Voltage ◽  
Single Atom ◽  
Ni Nanoparticles ◽  
Precious Metal Catalysts ◽  
Co Conversion ◽  
Co2 Electroreduction ◽  
Enhanced Adsorption ◽  
Direct Solid ◽  
Nanoparticle Catalyst

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.

Electrochemical reduction of carbon dioxide with nearly 100% carbon monoxide faradaic efficiency from vacancy-stabilized single-atom active sites

2021 ◽  
Author(s):  
Chenbao Lu ◽  
Kaiyue Jiang ◽  
Diana Tranca ◽  
Ning Wang ◽  
Hui Zhu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Energy Conversion ◽  
Electrochemical Reduction ◽  
Active Sites ◽  
Co2 Reduction ◽  
Reduction Reaction ◽  
Single Atom ◽  
Faradaic Efficiency ◽  
Co2 Reduction Reaction

Single-atom catalysts (SACs) have been rapidly rising as emerging materials in the field of energy conversion, especially for CO2 reduction reaction. However, the selectivity and running current are still beyond...

Au aerogel for selective CO2 electroreduction to CO: ultrafast preparation with high performance

2021 ◽  
Author(s):  
Shenglin Yan ◽  
Samah Awadh Mahyoub ◽  
Jing Lin ◽  
Chunxiao Zhang ◽  
Qing Hu ◽  
...  
Keyword(s):  
Active Sites ◽  
High Performance ◽  
Gelation Time ◽  
Active Surface ◽  
Active Surface Area ◽  
Hydrogen Electrode ◽  
Faradaic Efficiency ◽  
External Force Field ◽  
Co2 Electroreduction ◽  
Turbulence Mixing

Abstract Noble metal aerogels (NMAs) have been used in a variety of (photo-)electrocatalytic reactions, but pure Au aerogels (AG) have not been used in CO2 electroreduction to date. To explore the potential application in this direction, AG was prepared to be used as the cathode in CO2 electroreduction to CO. However, the gelation time of NMAs is usually very long, up to several weeks. Here, an excess NaBH4 and turbulence mixing-promoted gelation approach was developed by introducing magnetic stirring as an external force field, which therefore greatly shortened the formation time of Au gels to several seconds. The AG-3 (AG with Au loading of 0.003 g) exhibited a high CO Faradaic efficiency (FE) of 95.6% at an extremely low overpotential of 0.39 V, and over 91% of CO FE was reached in a wide window of -0.4 ~ -0.7 V vs. the reversible hydrogen electrode (RHE). Partial current density in CO was measured to be -19.35 mA cm-2 at -0.8 V vs. RHE under 1 atm of CO2. The excellent performance should be ascribed to its porous structure, abundant active sites, and large electrochemical active surface area. It provides a new method for preparation of AG with ultrafast gelation time and large production at room temperature, and the resulting pure AG was for the first time used in the field of CO2 electroreduction.

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