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Qiu J, Yuan J, Chu X, Chen S, Zhang J, Peng Z. Correlating Thickness and Phase of Single Co(OH) 2 Micro-Platelets to the Intrinsic Activity of Oxygen Evolution Electrocatalysis. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2402976. [PMID: 38963321 DOI: 10.1002/smll.202402976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Revised: 06/26/2024] [Indexed: 07/05/2024]
Abstract
Morphology, crystal phase, and its transformation are important structures that frequently determine electrocatalytic activity, but the correlations of intrinsic activity with them are not completely understood. Herein, using Co(OH)2 micro-platelets with well-defined structures (phase, thickness, area, and volume) as model electrocatalysts of oxygen evolution reaction, multiple in situ microscopy is combined to correlate the electrocatalytic activity with morphology, phase, and its transformation. Single-entity morphology and electrochemistry characterized by atomic force microscopy and scanning electrochemical cell microscopy reveal a thickness-dependent turnover frequency (TOF) of α-Co(OH)2. The TOF (≈9.5 s-1) of α-Co(OH)2 with ≈14 nm thickness is ≈95-fold higher than that (≈0.1 s-1) with ≈80 nm. Moreover, this thickness-dependent activity has a critical thickness of ≈30 nm, above which no thickness-dependence is observed. Contrarily, β-Co(OH)2 reveals a lower TOF (≈0.1 s-1) having no significant correlation with thickness. Combining single-entity electrochemistry with in situ Raman microspectroscopy, this thickness-dependent activity is explained by more reversible Co3+/Co2+ kinetics and larger ratio of active Co sites of thinner α-Co(OH)2, accompanied with faster phase transformation and more extensive surface restructuration. The findings highlight the interactions among thickness, ratio of active sites, kinetics of active sites, and phase transformation, and offer new insights into structure-activity relationships at single-entity level.
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Affiliation(s)
- Ji Qiu
- School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Jiangmei Yuan
- School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Xiaoqing Chu
- School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Shu Chen
- School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Jie Zhang
- School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
- Laboratory of Advanced Spectroelectrochemistry and Li-ion Batteries, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Zhangquan Peng
- Laboratory of Advanced Spectroelectrochemistry and Li-ion Batteries, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
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2
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Salek S, Byers JC. Influence of Particle Size on Mass Transport during the Oxygen Reduction Reaction at Single Silver Particles Using Scanning Electrochemical Cell Microscopy. J Phys Chem Lett 2024; 15:8494-8500. [PMID: 39133521 DOI: 10.1021/acs.jpclett.4c01832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Single entity electrochemical measurements enable insight into the electrocatalytic activity of individual particles based on composition, shape, and crystallographic orientation. In addition to structural effects, particle size can further influence electrocatalytic activity and reaction mechanisms through mass transport effects. In this work, electrodeposition was used to grow well-separated silver particles of varying sizes from 100 to 500 nm in radius. Using a multimicroscopy approach of scanning electrochemical cell microscopy combined with scanning electron microscopy, the electrocatalytic current of individual silver particles toward the oxygen reduction reaction was evaluated as a function of their size. It was found that the current density increased with decreasing particle radius, which was correlated to the mass transport of oxygen to the silver particle, demonstrating the importance of size dependent mass transport effects that can occur at the single particle level using scanning electrochemical cell microscopy and opening new opportunities for quantitative electrocatalysis measurements.
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Affiliation(s)
- Samaneh Salek
- Département de Chimie, Université du Québec à Montréal, Case Postale 8888, succursale Centre-Ville, Montréal, Québec H3C 3P8, Canada
| | - Joshua C Byers
- Département de Chimie, Université du Québec à Montréal, Case Postale 8888, succursale Centre-Ville, Montréal, Québec H3C 3P8, Canada
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3
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Clarke TB, Krushinski LE, Vannoy KJ, Colón-Quintana G, Roy K, Rana A, Renault C, Hill ML, Dick JE. Single Entity Electrocatalysis. Chem Rev 2024; 124:9015-9080. [PMID: 39018111 DOI: 10.1021/acs.chemrev.3c00723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/19/2024]
Abstract
Making a measurement over millions of nanoparticles or exposed crystal facets seldom reports on reactivity of a single nanoparticle or facet, which may depart drastically from ensemble measurements. Within the past 30 years, science has moved toward studying the reactivity of single atoms, molecules, and nanoparticles, one at a time. This shift has been fueled by the realization that everything changes at the nanoscale, especially important industrially relevant properties like those important to electrocatalysis. Studying single nanoscale entities, however, is not trivial and has required the development of new measurement tools. This review explores a tale of the clever use of old and new measurement tools to study electrocatalysis at the single entity level. We explore in detail the complex interrelationship between measurement method, electrocatalytic material, and reaction of interest (e.g., carbon dioxide reduction, oxygen reduction, hydrazine oxidation, etc.). We end with our perspective on the future of single entity electrocatalysis with a key focus on what types of measurements present the greatest opportunity for fundamental discovery.
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Affiliation(s)
- Thomas B Clarke
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Lynn E Krushinski
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Kathryn J Vannoy
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | | | - Kingshuk Roy
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Ashutosh Rana
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Christophe Renault
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - Megan L Hill
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jeffrey E Dick
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
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4
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Wu J, Wang S, Ji R, Kai D, Kong J, Liu S, Thitsartarn W, Tan BH, Chua MH, Xu J, Loh XJ, Yan Q, Zhu Q. In Situ Characterization Techniques for Electrochemical Nitrogen Reduction Reaction. ACS NANO 2024. [PMID: 39092833 DOI: 10.1021/acsnano.4c05956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
The electrochemical reduction of nitrogen to produce ammonia is pivotal in modern society due to its environmental friendliness and the substantial influence that ammonia has on food, chemicals, and energy. However, the current electrochemical nitrogen reduction reaction (NRR) mechanism is still imperfect, which seriously impedes the development of NRR. In situ characterization techniques offer insight into the alterations taking place at the electrode/electrolyte interface throughout the NRR process, thereby helping us to explore the NRR mechanism in-depth and ultimately promote the development of efficient catalytic systems for NRR. Herein, we introduce the popular theories and mechanisms of the electrochemical NRR and provide an extensive overview on the application of various in situ characterization approaches for on-site detection of reaction intermediates and catalyst transformations during electrocatalytic NRR processes, including different optical techniques, X-ray-based techniques, electron microscopy, and scanning probe microscopy. Finally, some major challenges and future directions of these in situ techniques are proposed.
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Affiliation(s)
- Jing Wu
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Republic of Singapore
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Republic of Singapore
| | - Suxi Wang
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Rong Ji
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Dan Kai
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Junhua Kong
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Songlin Liu
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Warintorn Thitsartarn
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Beng Hoon Tan
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Ming Hui Chua
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Republic of Singapore
| | - Jianwei Xu
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Republic of Singapore
| | - Xian Jun Loh
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
- Department of Material Science and Engineering, National University of Singapore, 9 Engineering Drive 1, #03-09 EA, Singapore 117575, Republic of Singapore
| | - Qingyu Yan
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Republic of Singapore
| | - Qiang Zhu
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Republic of Singapore
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Republic of Singapore
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5
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Gao T, An Q, Tang X, Yue Q, Zhang Y, Li B, Li P, Jin Z. Recent progress in energy-saving electrocatalytic hydrogen production via regulating the anodic oxidation reaction. Phys Chem Chem Phys 2024; 26:19606-19624. [PMID: 39011574 DOI: 10.1039/d4cp01680g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
Hydrogen energy with its advantages of high calorific value, renewable nature, and zero carbon emissions is considered an ideal candidate for clean energy in the future. The electrochemical decomposition of water, powered by renewable and clean energy sources, presents a sustainable and environmentally friendly approach to hydrogen production. However, the traditional electrochemical overall water-splitting reaction (OWSR) is limited by the anodic oxygen evolution reaction (OER) with sluggish kinetics. Although important advances have been made in efficient OER catalysts, the theoretical thermodynamic difficulty predetermines the inevitable large potential (1.23 V vs. RHE for the OER) and high energy consumption for the conventional water electrolysis to obtain H2. Besides, the generation of reactive oxygen species at high oxidation potentials can lead to equipment degradation and increase maintenance costs. Therefore, to address these challenges, thermodynamically favorable anodic oxidation reactions with lower oxidation potentials than the OER are used to couple with the cathodic hydrogen evolution reaction (HER) to construct new coupling hydrogen production systems. Meanwhile, a series of robust catalysts applied in these new coupled systems are exploited to improve the energy conversion efficiency of hydrogen production. Besides, the electrochemical neutralization energy (ENE) of the asymmetric electrolytes with a pH gradient can further promote the decrease in application voltage and energy consumption for hydrogen production. In this review, we aim to provide an overview of the advancements in electrochemical hydrogen production strategies with low energy consumption, including (1) the traditional electrochemical overall water splitting reaction (OWSR, HER-OER); (2) the small molecule sacrificial agent oxidation reaction (SAOR) and (3) the electrochemical oxidation synthesis reaction (EOSR) coupling with the HER (HER-SAOR, HER-EOSR), respectively; (4) regulating the pH gradient of the cathodic and anodic electrolytes. The operating principle, advantages, and the latest progress of these hydrogen production systems are analyzed in detail. In particular, the recent progress in the catalytic materials applied to these coupled systems and the corresponding catalytic mechanism are further discussed. Furthermore, we also provide a perspective on the potential challenges and future directions to foster advancements in electrocatalytic green sustainable hydrogen production.
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Affiliation(s)
- Taotao Gao
- Institute for Advanced Study and School of Mechanical Engineering, Chengdu University, Chengdu, 610106, P. R. China
| | - Qi An
- Institute for Advanced Study and School of Mechanical Engineering, Chengdu University, Chengdu, 610106, P. R. China
| | - Xiangmin Tang
- Institute for Advanced Study and School of Mechanical Engineering, Chengdu University, Chengdu, 610106, P. R. China
| | - Qu Yue
- Institute for Advanced Study and School of Mechanical Engineering, Chengdu University, Chengdu, 610106, P. R. China
| | - Yang Zhang
- Institute for Advanced Study and School of Mechanical Engineering, Chengdu University, Chengdu, 610106, P. R. China
| | - Bing Li
- Hubei Key Laboratory of Wudang Local Chinese Medicine Research, Hubei University of Medicine, Shiyan, 442000, P. R. China
| | - Panpan Li
- College of Materials Science and Engineering, Sichuan University, Chengdu, 610065, P. R. China
| | - Zhaoyu Jin
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, P. R. China.
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6
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Han S, Lee HJ, Kim T, Lim SY, Kim J. Flexible and Dynamic Light-Guided Electrochemiluminescence for Spatiotemporal Imaging of Photoelectrochemical Processes on Hematite. Anal Chem 2024; 96:11146-11154. [PMID: 38917341 DOI: 10.1021/acs.analchem.3c05097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
Here, we report an electrochemiluminescence (ECL)-based approach for imaging of local photoelectrochemical processes on hematite in a spatially and temporally controlled manner. The local processes were guided by flexible and dynamic light illumination, not requiring any prepatterned conductive features or photomasks, with a digital micromirror device (DMD). The imaging approach was based on light-addressable electrochemical reactions on hematite, resulting in photoinduced ECL emission for spatiotemporally resolved imaging of photoelectrochemical processes selectively guided by light illumination. After clarifying the capability of hematite as a photosensitive electrode, we validated that the illuminated hematite exhibited stable light-guided ECL emission in correspondence with the illuminated area, with a spatial resolution of 0.8 μm and a temporal resolution of 1 μs, even over a long period of 6 h. More importantly, this study exemplified the simple yet effective ECL-based approach for electrochemical visualization of local photoelectrochemical processes guided by flexible and dynamic adjustment of light illumination in a spatiotemporally controlled way.
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Affiliation(s)
- Sungeun Han
- Department of Chemistry, Research Institute for Basic Science, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Hyun Joo Lee
- Department of Chemistry, Research Institute for Basic Science, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Taeyoon Kim
- Department of Chemistry, Research Institute for Basic Science, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Sung Yul Lim
- Department of Chemistry, Research Institute for Basic Science, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Joohoon Kim
- Department of Chemistry, Research Institute for Basic Science, Kyung Hee University, Seoul 02447, Republic of Korea
- KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul 02447, Republic of Korea
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7
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Ryu CH, Ren H. Simultaneous Mapping of Electrocatalytic Activity and Selectivity via Hybrid Scanning Electrochemical Probe Microscopy. NANO LETTERS 2024; 24:6112-6116. [PMID: 38717098 PMCID: PMC11141319 DOI: 10.1021/acs.nanolett.4c01280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
Nanoscale scanning electrochemical probe microscopy started to elucidate the heterogeneity of electrocatalytic activity at electrode surfaces. However, understanding the heterogeneity in product selectivity, another crucial aspect of interfacial reactivity, remains challenging. Herein, we introduce a method combining scanning electrochemical microscopy (SECM) and scanning electrochemical cell microscopy (SECCM) to enable the spatially resolved mapping of both activity and selectivity in electrocatalysis. A dual-channel nanopipette probe was developed: one channel for activity mapping and the other for product detection with a high collection efficiency (>95%) and sensitivity. Simultaneous mapping of activity and selectivity in the oxygen reduction reaction (ORR) is demonstrated. Combined with colocalized crystal orientation mapping, we uncover the local electrocatalytic performance of ORR at different facets on polycrystalline Pt and Au. The high-resolution selectivity mapping enabled by our method with colocalized structural characterization can provide structure-activity-selectivity relationships that are often unavailable in ensemble measurement, holding promise for understanding key structural motifs controlling interfacial reactivity.
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Affiliation(s)
- C Hyun Ryu
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Hang Ren
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
- Center for Electrochemistry, The University of Texas at Austin, Austin, Texas 78712, United States
- Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
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8
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Liu K, Li H, Xie M, Wang P, Jin Z, Liu Y, Zhou M, Li P, Yu G. Thermally Enhanced Relay Electrocatalysis of Nitrate-to-Ammonia Reduction over Single-Atom-Alloy Oxides. J Am Chem Soc 2024; 146:7779-7790. [PMID: 38466142 DOI: 10.1021/jacs.4c00429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
The electrochemical nitrate reduction reaction (NO3RR) holds promise for converting nitrogenous pollutants to valuable ammonia products. However, conventional electrocatalysis faces challenges in effectively driving the complex eight-electron and nine-proton transfer process of the NO3RR while also competing with the hydrogen evolution reaction. In this study, we present the thermally enhanced electrocatalysis of nitrate-to-ammonia conversion over nickel-modified copper oxide single-atom alloy oxide nanowires. The catalyst demonstrates improved ammonia production performance with a Faradaic efficiency of approximately 80% and a yield rate of 9.7 mg h-1 cm-2 at +0.1 V versus a reversible hydrogen electrode at elevated cell temperatures. In addition, this thermally enhanced electrocatalysis system displays impressive stability, interference resistance, and favorable energy consumption and greenhouse gas emissions for the simulated industrial wastewater treatment. Complementary in situ analyses confirm that the significantly superior relay of active hydrogen species formed at Ni sites facilitates the thermal-field-coupled electrocatalysis of Cu surface-adsorbed *NOx hydrogenation. Theoretical calculations further support the thermodynamic and kinetic feasibility of the relay catalysis mechanism for the NO3RR over the Ni1Cu model catalyst. This study introduces a conceptual thermal-electrochemistry approach for the synergistic regulation of complex catalytic processes, highlighting the potential of multifield-coupled catalysis to advance sustainable-energy-powered chemical synthesis technologies.
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Affiliation(s)
- Kui Liu
- College of Materials Science and Engineering, Sichuan University, Chengdu 610065, China
| | - Hongmei Li
- College of Materials Science and Engineering, Sichuan University, Chengdu 610065, China
| | - Minghao Xie
- Materials Science and Engineering Program and Walker Department of Mechanical Engineering, the University of Texas at Austin, Austin, Texas 78712, United States
| | - Pengfei Wang
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Zhaoyu Jin
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Yuanting Liu
- College of Materials Science and Engineering, Sichuan University, Chengdu 610065, China
| | - Min Zhou
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin, China
| | - Panpan Li
- College of Materials Science and Engineering, Sichuan University, Chengdu 610065, China
| | - Guihua Yu
- Materials Science and Engineering Program and Walker Department of Mechanical Engineering, the University of Texas at Austin, Austin, Texas 78712, United States
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9
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Li H, Li P, Guo Y, Jin Z. Electrochemical Probing the Site Reactivity in Iron Single-Atom Catalysts for Electrocatalytic Nitrate Reduction to Ammonia. Anal Chem 2024; 96:997-1002. [PMID: 38176015 DOI: 10.1021/acs.analchem.3c05095] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
Single-atom catalysts (SACs), specifically iron single atoms dispersed on nitrogen-doped carbon (Fe-NC), have shown promising potential in the electrocatalytic reduction of nitrate to ammonia (NitRR), but there is a lack of understanding of their intrinsic activity. The conventional measurements often overlook the intrinsic performance of SACs, leading to significant underestimation. This study presents an in situ electrochemical probing protocol, using two poisoning molecules (SCN- and NO2-), to characterize the reactivity of Fe sites in Fe-NC SACs for NitRR. The technique aids in quantifying the yield rate of ammonia on Fe sites and the active site number. The findings reveal the intrinsic turnover frequency (TOF) based on the number and ammonia yield rate of Fe sites, challenging the current understanding of SACs' inherent performances. This unique approach holds considerable potential for determining the intrinsic activity of other SACs in complex reactions, opening new avenues for the exploration of electrocatalytic processes.
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Affiliation(s)
- Hongmei Li
- College of Chemistry, Sichuan University, Chengdu 610065, P. R. China
| | - Panpan Li
- College of Materials Science and Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Yong Guo
- College of Chemistry, Sichuan University, Chengdu 610065, P. R. China
| | - Zhaoyu Jin
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 611731, P. R. China
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10
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Gao T, Qiu L, Xie M, Jin Z, Li P, Yu G. Defect-stabilized and oxygen-coordinated iron single-atom sites facilitate hydrogen peroxide electrosynthesis. MATERIALS HORIZONS 2023; 10:4270-4277. [PMID: 37556212 DOI: 10.1039/d3mh00882g] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
The selective two-electron electrochemical oxygen reduction reaction (ORR) for hydrogen peroxide (H2O2) production is a promising and green alternative method to the current energy-intensive anthraquinone process used in industry. In this study, we develop a single-atom catalyst (CNT-D-O-Fe) by anchoring defect-stabilized and oxygen-coordinated iron atomic sites (Fe-O4) onto porous carbon nanotubes using a local etching strategy. Compared to O-doped CNTs with vacancy defects (CNT-D-O) and oxygen-coordinated Fe single-atom site modifying CNTs without a porous structure (CNT-O-Fe), CNT-D-O-Fe exhibits the highest H2O2 selectivity of 94.4% with a kinetic current density of 13.4 mA cm-2. Fe-O4 single-atom sites in the catalyst probably contribute to the intrinsic reactivity for the two-electron transfer process while vacancy defects greatly enhance the electrocatalytic stability. Theoretical calculations further support that the coordinated environment and defective moiety in CNT-D-O-Fe could efficiently optimize the adsorption strength of the *OOH intermediate over the Fe single atomic active sites. This contribution sheds light on the potential of defect-stabilized and oxygen-coordinated single-atom metal sites as a promising avenue for the rational design of highly efficient and selective catalysts towards various electrocatalytic reactions.
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Affiliation(s)
- Taotao Gao
- College of Materials Science and Engineering, Sichuan University, Chengdu, 610065, P. R. China.
- Institute for Advanced Study, Chengdu University, Chengdu, 610106, P. R. China
| | - Lu Qiu
- Institute for Advanced Study, Chengdu University, Chengdu, 610106, P. R. China
- College of Chemical Engineering, Sichuan University, Chengdu, 610065, P. R. China
| | - Minghao Xie
- Materials Science and Engineering Program and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA.
| | - Zhaoyu Jin
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, P. R. China
| | - Panpan Li
- College of Materials Science and Engineering, Sichuan University, Chengdu, 610065, P. R. China.
| | - Guihua Yu
- Materials Science and Engineering Program and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA.
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11
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Li P, Liao L, Fang Z, Su G, Jin Z, Yu G. A multifunctional copper single-atom electrocatalyst aerogel for smart sensing and producing ammonia from nitrate. Proc Natl Acad Sci U S A 2023; 120:e2305489120. [PMID: 37339226 PMCID: PMC10293845 DOI: 10.1073/pnas.2305489120] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 05/18/2023] [Indexed: 06/22/2023] Open
Abstract
Despite modern chemistry's success in providing affordable fertilizers for feeding the population and supporting the ammonia industry, ineffective nitrogen management has led to pollution of water resources and air, contributing to climate change. Here, we report a multifunctional copper single-atom electrocatalyst-based aerogel (Cu SAA) that integrates the multiscale structure of coordinated single-atomic sites and 3D channel frameworks. The Cu SAA demonstrates an impressive faradaic efficiency of 87% for NH3 synthesis, as well as remarkable sensing performance with detection limits of 0.15 ppm for NO3- and 1.19 ppm for NH4+. These multifunctional features enable precise control and conversion of nitrate to ammonia in the catalytic process, facilitating accurate regulation of the ammonium and nitrate ratios in fertilizers. We thus designed the Cu SAA into a smart and sustainable fertilizing system (SSFS), a prototype device for on-site automatic recycling of nutrients with precisely controlled nitrate/ammonium concentrations. The SSFS represents a forward step toward sustainable nutrient/waste recycling, thus permitting efficient nitrogen utilization of crops and mitigating pollutant emissions. This contribution exemplifies how electrocatalysis and nanotechnology can be potentially leveraged to enable sustainable agriculture.
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Affiliation(s)
- Panpan Li
- Materials Science and Engineering Program and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX78712
- College of Materials Science and Engineering, Sichuan University, Chengdu610065, China
| | - Ling Liao
- College of Horticulture and College of Science, Sichuan Agricultural University, Chengdu611130, China
| | - Zhiwei Fang
- Materials Science and Engineering Program and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX78712
| | - Gehong Su
- College of Horticulture and College of Science, Sichuan Agricultural University, Chengdu611130, China
| | - Zhaoyu Jin
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu610054, China
| | - Guihua Yu
- Materials Science and Engineering Program and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX78712
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