Amorphous carbon nitride thin fims, a-CNx, are potentially low cost candidates for electrochemical nitrate treatment by comparison to boron doped diamond electrodes. In aqueous media, a-CNx electrodes are characterized by a large potential window and, in acidic pH solutions, no surface charge capacitive contribution. In perchloric acid at pH 1, nitrate reduction occurs at the negative limit of a potential domain without any significant redox reaction over almost 1 Volt. In this domain, in the presence of a nitrate salt, a bell-shaped behaviour was observed for the interfacial capacitance. Differences were evidenced according to the solvation state of the cations (Na+, K+, Li+, Cs+, (CH3)4N+, (C2H5)4N+), depending on the cation size. Experimental capacitance data were simulated by using the phenomenological theory developed by Kornyshev in the case of ionic liquids. A good agreement was obtained assuming a compact layer in series with the highly structured diffuse layer and taking into account the short-range ion-ion interactions. Thus, at the a-CNx/aqueous electrolyte interface, nitrate anions are engaged into strong anion-cation interactions (ion pairing) especially with small sized cations, leading to nitrate anion trapping in the multilayered interfacial region with a possible negative effect on the nitrate ions electroreduction.
{"title":"Unexpected bell-shaped double layer capacitance promoted by nitrate anions at a-CNx / aqueous electrolyte interface and simulated with the lattice-gas model","authors":"Nathalie SIMON, Catherine DEBIEMME-CHOUVY, Florence BILLON, Hubert CACHET","doi":"10.1016/j.electacta.2024.145165","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145165","url":null,"abstract":"Amorphous carbon nitride thin fims, a-CN<sub>x</sub>, are potentially low cost candidates for electrochemical nitrate treatment by comparison to boron doped diamond electrodes. In aqueous media, a-CN<sub>x</sub> electrodes are characterized by a large potential window and, in acidic pH solutions, no surface charge capacitive contribution. In perchloric acid at pH 1, nitrate reduction occurs at the negative limit of a potential domain without any significant redox reaction over almost 1 Volt. In this domain, in the presence of a nitrate salt, a bell-shaped behaviour was observed for the interfacial capacitance. Differences were evidenced according to the solvation state of the cations (Na<sup>+</sup>, K<sup>+</sup>, Li<sup>+</sup>, Cs<sup>+</sup>, (CH<sub>3</sub>)<sub>4</sub>N<sup>+</sup>, (C<sub>2</sub>H<sub>5</sub>)<sub>4</sub>N<sup>+</sup>), depending on the cation size. Experimental capacitance data were simulated by using the phenomenological theory developed by Kornyshev in the case of ionic liquids. A good agreement was obtained assuming a compact layer in series with the highly structured diffuse layer and taking into account the short-range ion-ion interactions. Thus, at the a-CNx/aqueous electrolyte interface, nitrate anions are engaged into strong anion-cation interactions (ion pairing) especially with small sized cations, leading to nitrate anion trapping in the multilayered interfacial region with a possible negative effect on the nitrate ions electroreduction.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":null,"pages":null},"PeriodicalIF":6.6,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.electacta.2024.145184
Zahra Azizi, Mohammad Fasihi, Sajad Rasouli
Polypropylene-grafted-maleic anhydride (PPMA) as a modifier of polypropylene (PP) at different contents and the corona radiation for surface ionization at various modification times were applied to promote the PP-based separator efficiency. The determined microstructural characteristics showed an improvement in the separator's porosity of 6-139% at the tension amounts of 700-900%, however, more stretching hurts the mechanical properties. The electrostatic interactions formed between the electrolytes and anhydrides increased the electrolyte sorption capacity in the samples and the surface wettability by 740% and 25%, respectively. The electrical test results indicated that the anhydrides led to capturing the electrolytes in the separator and created a resistance against the ion diffusion. This phenomenon reduced the separator resistance from 475 to 165 Ω, and enhanced the charge capacity and ion conductivity from 585 to 871 mAh/g and 0.29 to 0.34 S.cm-1, respectively, while the PPMA content increased from 20 to 60 wt.%. The achieved FT-IR illustrated that the ionization caused the creation of more polar groups in the LIB separator, which increased the bulk and surface wettability by 420% and 21%, respectively, without any change in the microstructure of the separator. However, raising the exposure time in the radiation process decomposed the sample surface and led to damage in the separator microstructure. This issue reduced the separator porosity as well as the electrolyte absorption amount and ion conductivity.
{"title":"Enhancing Polypropylene-Based Separator Efficiency in Lithium-Ion Batteries through Maleic Anhydride Addition and Corona Radiation Modification","authors":"Zahra Azizi, Mohammad Fasihi, Sajad Rasouli","doi":"10.1016/j.electacta.2024.145184","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145184","url":null,"abstract":"Polypropylene-<em>grafted</em>-maleic anhydride (PPMA) as a modifier of polypropylene (PP) at different contents and the corona radiation for surface ionization at various modification times were applied to promote the PP-based separator efficiency. The determined microstructural characteristics showed an improvement in the separator's porosity of 6-139% at the tension amounts of 700-900%, however, more stretching hurts the mechanical properties. The electrostatic interactions formed between the electrolytes and anhydrides increased the electrolyte sorption capacity in the samples and the surface wettability by 740% and 25%, respectively. The electrical test results indicated that the anhydrides led to capturing the electrolytes in the separator and created a resistance against the ion diffusion. This phenomenon reduced the separator resistance from 475 to 165 Ω, and enhanced the charge capacity and ion conductivity from 585 to 871 mAh/g and 0.29 to 0.34 S.cm<sup>-1</sup>, respectively, while the PPMA content increased from 20 to 60 <em>wt</em>.%. The achieved FT-IR illustrated that the ionization caused the creation of more polar groups in the LIB separator, which increased the bulk and surface wettability by 420% and 21%, respectively, without any change in the microstructure of the separator. However, raising the exposure time in the radiation process decomposed the sample surface and led to damage in the separator microstructure. This issue reduced the separator porosity as well as the electrolyte absorption amount and ion conductivity.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":null,"pages":null},"PeriodicalIF":6.6,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.electacta.2024.145179
Deepika Choudhary, Ritu Bala, Monika Shrivastav, Rajnish Dhiman
A high-performance and long-lasting, rechargeable Zn-air battery requires a reliable and effective bifunctional catalyst material to facilitate the oxygen reduction and oxygen evolution reactions during the battery operation. Manganese oxide (MnO2) is a promising non-precious perspective due to its multivalency and various polymorphic structures that effectively catalyze oxygen evolution and reduction. In the present work, MnO2 nanowires (NWs) have been integrated with over-reduced graphene oxide (rGO) in various concentrations via a facile hydrothermal route. The synthesized materials, tested in lab-made zinc-air battery devices fabricated using gel polymer electrolyte, exhibit a significant enhancement in the performance and 2-3 times the cycle life compared to the bare MnO2. The ZAB device was tested for galvanostatic charge-discharge technique, and results exhibit a cycle life of 165 h (495 cycles@20 minutes per cycle) when discharged up to 1.0 V at a current density of 5.2 mA/cm2 and displayed a capacity of 731 mAh/gZn. Reduced graphene oxide acts as a support material that enhances the conductivity and surface area of the active material and also provides active sites for catalysis. This work signifies the importance of the engineering of the catalyst, support material, and additives, as slight changes may result in a significant enhancement in the cycle life. The appropriate composition of catalyst and support material and a compatible gel polymer electrolyte facilitates the fabrication of flexible zinc-air batteries for various applications.
{"title":"MnO2/rGO bifunctional catalyst and support materials for gel polymer electrolyte based Zn-air batteries","authors":"Deepika Choudhary, Ritu Bala, Monika Shrivastav, Rajnish Dhiman","doi":"10.1016/j.electacta.2024.145179","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145179","url":null,"abstract":"A high-performance and long-lasting, rechargeable Zn-air battery requires a reliable and effective bifunctional catalyst material to facilitate the oxygen reduction and oxygen evolution reactions during the battery operation. Manganese oxide (MnO<sub>2</sub>) is a promising non-precious perspective due to its multivalency and various polymorphic structures that effectively catalyze oxygen evolution and reduction. In the present work, MnO<sub>2</sub> nanowires (NWs) have been integrated with over-reduced graphene oxide (rGO) in various concentrations via a facile hydrothermal route. The synthesized materials, tested in lab-made zinc-air battery devices fabricated using gel polymer electrolyte, exhibit a significant enhancement in the performance and 2-3 times the cycle life compared to the bare MnO<sub>2</sub>. The ZAB device was tested for galvanostatic charge-discharge technique, and results exhibit a cycle life of 165 h (495 cycles@20 minutes per cycle) when discharged up to 1.0 V at a current density of 5.2 mA/cm2 and displayed a capacity of 731 mAh/g<sub>Zn</sub>. Reduced graphene oxide acts as a support material that enhances the conductivity and surface area of the active material and also provides active sites for catalysis. This work signifies the importance of the engineering of the catalyst, support material, and additives, as slight changes may result in a significant enhancement in the cycle life. The appropriate composition of catalyst and support material and a compatible gel polymer electrolyte facilitates the fabrication of flexible zinc-air batteries for various applications.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":null,"pages":null},"PeriodicalIF":6.6,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.electacta.2024.145185
Molly E Keal, Lydia Clewlow, Emily Roberts, Neil V Rees
The recovery of ruthenium from low-concentration solutions poses a significant challenge due to its scarcity and rising economic value, and nano-impact electrochemistry has emerged as a promising method for efficient recovery of critical metals from solution through deposition during impacts of non-metallic nanoparticles. In this study, we investigate the redox chemistry of ruthenium on carbon black via the impact technique and demonstrate the ability to recover ruthenium from solution. The reduction (electrodeposition) and oxidation of Ru3+ ions in solution onto carbon black nanoparticles can be observed during nano-impacts with the respective onset potentials of these redox processes agreeing with those obtained from solution voltammetry. Upscaled experiments focusing on the electroreduction process, led to the formation of RuOx deposits, confirmed through scanning electron microscopy/energy-dispersive X-ray (SEM/EDX) analysis, X-ray photoelectron spectroscopy (XPS) analysis, and thermogravimetric analysis (TGA). Under partially-optimised conditions, >90% recovery of Ru(III) from a 1mM solution was achieved in ca. 8 hours.
{"title":"Electrochemical Recovery of Ruthenium via Carbon Black Nano-Impacts","authors":"Molly E Keal, Lydia Clewlow, Emily Roberts, Neil V Rees","doi":"10.1016/j.electacta.2024.145185","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145185","url":null,"abstract":"The recovery of ruthenium from low-concentration solutions poses a significant challenge due to its scarcity and rising economic value, and nano-impact electrochemistry has emerged as a promising method for efficient recovery of critical metals from solution through deposition during impacts of non-metallic nanoparticles. In this study, we investigate the redox chemistry of ruthenium on carbon black via the impact technique and demonstrate the ability to recover ruthenium from solution. The reduction (electrodeposition) and oxidation of Ru<sup>3+</sup> ions in solution onto carbon black nanoparticles can be observed during nano-impacts with the respective onset potentials of these redox processes agreeing with those obtained from solution voltammetry. Upscaled experiments focusing on the electroreduction process, led to the formation of RuOx deposits, confirmed through scanning electron microscopy/energy-dispersive X-ray (SEM/EDX) analysis, X-ray photoelectron spectroscopy (XPS) analysis, and thermogravimetric analysis (TGA). Under partially-optimised conditions, >90% recovery of Ru(III) from a 1mM solution was achieved in ca. 8 hours.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":null,"pages":null},"PeriodicalIF":6.6,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.electacta.2024.145172
Tatyana Reshetenko, Ying Sun, Thomas Kadyk, Michael Eikerling, Andrei Kulikovsky
A recent physics–based model for liquid and gaseous water transport in the cathode catalyst layer (CCL) is incorporated into our 1d ＋ 1d model for the PEM fuel cell impedance. The model includes parametric dependencies of the CCL oxygen diffusivity and proton conductivity on the liquid saturation. Fitting of the 1d ＋ 1d model to experimental impedance spectra of a PEM fuel cell reveals two intriguing effects. Contrary to common belief, the liquid water saturation in the CCL is nearly independent of cell current density due to the growing liquid pressure gradient that drives liquid water removal from the CCL. Further, the “dry” oxygen diffusivity of the catalyst layer increases with cell current density. Apparently, at small current density, electrochemical conversion proceeds primarily in narrow pores, where the Knudsen oxygen diffusivity is low. With growing current density, larger and better connected pores with higher oxygen diffusivity dominate in the current conversion, leading to increase in effective oxygen diffusivity observed in impedance spectroscopy data.
{"title":"An impedance spectroscopy study to unravel the effect of water on proton and oxygen transport in PEM fuel cells","authors":"Tatyana Reshetenko, Ying Sun, Thomas Kadyk, Michael Eikerling, Andrei Kulikovsky","doi":"10.1016/j.electacta.2024.145172","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145172","url":null,"abstract":"A recent physics–based model for liquid and gaseous water transport in the cathode catalyst layer (CCL) is incorporated into our 1d ＋ 1d model for the PEM fuel cell impedance. The model includes parametric dependencies of the CCL oxygen diffusivity and proton conductivity on the liquid saturation. Fitting of the 1d ＋ 1d model to experimental impedance spectra of a PEM fuel cell reveals two intriguing effects. Contrary to common belief, the liquid water saturation in the CCL is nearly independent of cell current density due to the growing liquid pressure gradient that drives liquid water removal from the CCL. Further, the “dry” oxygen diffusivity of the catalyst layer increases with cell current density. Apparently, at small current density, electrochemical conversion proceeds primarily in narrow pores, where the Knudsen oxygen diffusivity is low. With growing current density, larger and better connected pores with higher oxygen diffusivity dominate in the current conversion, leading to increase in effective oxygen diffusivity observed in impedance spectroscopy data.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":null,"pages":null},"PeriodicalIF":6.6,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The instability of transition metal oxides during long-term electrolysis significantly impedes their application in various electrochemical reactions. This study demonstrates an interfacial doping strategy utilizing bismuth to enhance the stability of CuO catalyst during glucose electrooxidation in alkaline media. This methodology reduces activity decay from 55% to 6% after 8 hours of electrolysis, lowering charge transfer resistance without compromising the intrinsic catalytic activity of the Cu sites. The enhanced stability can be attributed to the formation of a Cu−O−Bi interface on the catalyst surface, which mitigates the interfacial Cu dissolution, as evidenced by in situ electrochemical impedance analysis. These findings underscore the potential efficacy of bismuth doping strategies in advancing the development of robust and efficient catalysts for anodic catalysis. Furthermore, this research highlights the prospect of employing main group metals as dopants in transition metal oxides, thereby expanding the horizon of possibilities in catalyst design.
{"title":"Bismuth Doping Unlocks Stability of Copper Oxides in Anodic Reaction: A Case Analysis of Glucose Electrooxidation","authors":"Jiajing Zhong, Junwei Ge, Zhaohan Wu, Qian Zhang, Elissaios Stavrou, Weiran Zheng","doi":"10.1016/j.electacta.2024.145178","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145178","url":null,"abstract":"The instability of transition metal oxides during long-term electrolysis significantly impedes their application in various electrochemical reactions. This study demonstrates an interfacial doping strategy utilizing bismuth to enhance the stability of CuO catalyst during glucose electrooxidation in alkaline media. This methodology reduces activity decay from 55% to 6% after 8 hours of electrolysis, lowering charge transfer resistance without compromising the intrinsic catalytic activity of the Cu sites. The enhanced stability can be attributed to the formation of a Cu−O−Bi interface on the catalyst surface, which mitigates the interfacial Cu dissolution, as evidenced by <em>in situ</em> electrochemical impedance analysis. These findings underscore the potential efficacy of bismuth doping strategies in advancing the development of robust and efficient catalysts for anodic catalysis. Furthermore, this research highlights the prospect of employing main group metals as dopants in transition metal oxides, thereby expanding the horizon of possibilities in catalyst design.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":null,"pages":null},"PeriodicalIF":6.6,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, we successfully synthesized novel cobalt bismuth oxide (CBO) using various solvothermal methods. These materials were then utilized as active electrode materials for supercapacitors and photocatalysts. A variety of techniques was employed to analyse the crystal structure, morphology, and surface of the prepared samples. The morphological analysis revealed that S1 (nanosheet) and S3 (nanoneedles) in nature. The S3 electrode demonstrated a specific capacitance of 270.9 F g-1 at a current density of 1 A/g, compared to the S1 electrode, which exhibited a specific capacitance of 181.7 F g-1 under the same conditions. Furthermore, when subjected to a current density of 3 A g-1, the S1 and S3 retained 79 % and 68% of their capacitance, respectively after 2000 cycles. The morphological variations in the samples play a crucial role in capacitive performance and mechanism, characterised by a significant presence of lattice defects and oxygen vacancies.
在这项研究中，我们采用多种溶热法成功合成了新型氧化钴铋（CBO）。这些材料随后被用作超级电容器和光催化剂的活性电极材料。研究人员采用多种技术分析了所制备样品的晶体结构、形态和表面。形态分析表明，样品具有 S1（纳米片）和 S3（纳米针）两种性质。S3 电极在电流密度为 1 A/g 时的比电容为 270.9 F g-1，而 S1 电极在相同条件下的比电容为 181.7 F g-1。此外，当电流密度为 3 A g-1 时，S1 和 S3 在 2000 次循环后分别保留了 79% 和 68% 的电容。样品的形态变化对电容性能和机理起着至关重要的作用，其特点是存在大量晶格缺陷和氧空位。
{"title":"Influence of Morphological Variations in Cobalt Bismuth Oxide on Supercapacitor Performance","authors":"Sneha Mondal, Karthik Dilly Rajan, Maheswaran Rathinam, Vattikondala Ganesh","doi":"10.1016/j.electacta.2024.145173","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145173","url":null,"abstract":"In this study, we successfully synthesized novel cobalt bismuth oxide (CBO) using various solvothermal methods. These materials were then utilized as active electrode materials for supercapacitors and photocatalysts. A variety of techniques was employed to analyse the crystal structure, morphology, and surface of the prepared samples. The morphological analysis revealed that S1 (nanosheet) and S3 (nanoneedles) in nature. The S3 electrode demonstrated a specific capacitance of 270.9 F g<sup>-1</sup> at a current density of 1 A/g, compared to the S1 electrode, which exhibited a specific capacitance of 181.7 F g<sup>-1</sup> under the same conditions. Furthermore, when subjected to a current density of 3 A g<sup>-1</sup>, the S1 and S3 retained 79 % and 68% of their capacitance, respectively after 2000 cycles. The morphological variations in the samples play a crucial role in capacitive performance and mechanism, characterised by a significant presence of lattice defects and oxygen vacancies.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":null,"pages":null},"PeriodicalIF":6.6,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-30DOI: 10.1016/j.electacta.2024.145166
Mokyeon Cho, Hyungkuk Ju, Sooan Bae, Sungyool Bong, Jaeyoung Lee
Ammonia production, which is vital for agricultural and industrial applications, typically relies on energy-intensive processes that contribute to global CO2 emissions. Electrochemical nitrogen reduction is a promising alternative, although it faces challenges such as low yield and selectivity. Transition-metal-based catalysts, particularly Cu, are promising for overcoming these limitations. Cu3PS4 catalysts were synthesized and evaluated using a 9 cm2-scale electrode, revealing enhanced performance attributed to change in the crystal and electronic structure of Cu, facilitating N2 adsorption and improving the reaction activity. Notably, the ammonia synthesis rate reached 128 μg h-1 mgcat-1 at -1.0 V vs. RHE and faradaic efficiency was 34% at -0.8 V vs. RHE. These findings provide potential insights into the improvement of practical electrochemical synthesis of ammonia.
{"title":"Scalable ammonia synthesis on the modified crystal structure of Cu3PS4 electrocatalyst","authors":"Mokyeon Cho, Hyungkuk Ju, Sooan Bae, Sungyool Bong, Jaeyoung Lee","doi":"10.1016/j.electacta.2024.145166","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145166","url":null,"abstract":"Ammonia production, which is vital for agricultural and industrial applications, typically relies on energy-intensive processes that contribute to global CO<sub>2</sub> emissions. Electrochemical nitrogen reduction is a promising alternative, although it faces challenges such as low yield and selectivity. Transition-metal-based catalysts, particularly Cu, are promising for overcoming these limitations. Cu<sub>3</sub>PS<sub>4</sub> catalysts were synthesized and evaluated using a 9 cm<sup>2</sup>-scale electrode, revealing enhanced performance attributed to change in the crystal and electronic structure of Cu, facilitating N<sub>2</sub> adsorption and improving the reaction activity. Notably, the ammonia synthesis rate reached 128 μg h<sup>-1</sup> mg<sub>cat</sub><sup>-1</sup> at -1.0 V vs. RHE and faradaic efficiency was 34% at -0.8 V vs. RHE. These findings provide potential insights into the improvement of practical electrochemical synthesis of ammonia.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":null,"pages":null},"PeriodicalIF":6.6,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-30DOI: 10.1016/j.electacta.2024.145174
Tristan Asset, Alexandr G. Oshchepkov, Frédéric Maillard, Galina A. Tsirlina
Electrocatalysis has always been evolving and diversifying. Driven by expectations of advanced practical applications, the field is incorporating increasingly complex catalytic materials and leveraging insights from advanced spectroscopic, microscopic, and diffraction techniques. A significant challenge lies in linking these innovations to the fundamentals of electrocatalysis, such as the role of the charged interface, and the effects of particle size, support, spillover of adsorbates, identification of reaction intermediates, and further specification of the overall catalytic reaction pathways. This review briefly outlines the development of the electrocatalysis field and presents representative examples addressing this challenge. In line with the purpose of this review, the selection of cited articles is curated to highlight the numerous contributions of a scientist and friend whose research exemplifies the evolution of the field over the past decades.
{"title":"Electrocatalysis, diverse and forever young","authors":"Tristan Asset, Alexandr G. Oshchepkov, Frédéric Maillard, Galina A. Tsirlina","doi":"10.1016/j.electacta.2024.145174","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145174","url":null,"abstract":"Electrocatalysis has always been evolving and diversifying. Driven by expectations of advanced practical applications, the field is incorporating increasingly complex catalytic materials and leveraging insights from advanced spectroscopic, microscopic, and diffraction techniques. A significant challenge lies in linking these innovations to the fundamentals of electrocatalysis, such as the role of the charged interface, and the effects of particle size, support, spillover of adsorbates, identification of reaction intermediates, and further specification of the overall catalytic reaction pathways. This review briefly outlines the development of the electrocatalysis field and presents representative examples addressing this challenge. In line with the purpose of this review, the selection of cited articles is curated to highlight the numerous contributions of a scientist and friend whose research exemplifies the evolution of the field over the past decades.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":null,"pages":null},"PeriodicalIF":6.6,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-29DOI: 10.1016/j.electacta.2024.145169
Alisha Dhakal, Felio A Perez, Sanjay R Mishra
This study synthesizes cuboidal-shaped hierarchical Mn2O3 (MNO) particles using a simple hydrothermal technique with Good's buffer piperazine and examines their electrochemical performance. The research explores how varying piperazine concentrations (piperazine concentration x in MNO-x) affect the structure and electrochemical properties of the MNO particles. X-ray diffraction (XRD) confirms the crystalline nature of MNO while scanning electron microscopy reveals that piperazine concentration influences the particles’ shape, size, and morphology. The MNO synthesized with 6 mmole piperazine (MNO-6) has the highest surface area of 8.67 m²/g. Electrochemical tests in 1 M and 6 M KOH electrolytes show that MNO-6 achieves the highest specific capacitance, with 440 F/g in 1 M and 952 F/g in 6 M KOH at a 1 mV/s scan rate. At a 1 A/g current density, MNO-6 exhibits a specific capacitance of ∼545.8 F/g in 1 M KOH and 809.0 F/g in 6 M KOH, with corresponding energy densities of 27.3 Wh/kg and 40.4 Wh/kg, and power densities of 315.7 W/kg and 365 W/kg, respectively. The superior electrochemical performance is attributed to the high surface area and porous structure of MNO synthesized with piperazine, highlighting its potential for advanced energy storage applications.
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