ACS electrochemistry最新文献

{"title":"Detailed Understanding of the Electrochemistry and Oxygen Reduction Activity of La_1-<i>x</i> Ca _<i>x</i> MnO₃ Obtained by In Situ XAS and XES.","authors":"Veronica Celorrio, Haoliang Huang, Shusaku Hayama, David J Fermin, Andrea E Russell","doi":"10.1021/acselectrochem.5c00541","DOIUrl":"10.1021/acselectrochem.5c00541","url":null,"abstract":"<p><p>Understanding the interplay between redox behavior and structural stability is crucial for the development of transition metal oxides in electrocatalysis. In this work, we use both X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) to investigate the electrochemical response of Mn-based perovskite oxides (La_1-<i>x</i> Ca _<i>x</i> MnO₃) under oxygen reduction reaction (ORR) conditions. This dual approach enables tracking of changes in both the oxidation state and local coordination environment. Mn Kβ XES data show that oxidation-state changes are reversible, despite a shift in transition potentials across a range of compositions, including CaMnO_3. In contrast, Mn K-edge EXAFS analyses reveal that while LaMnO₃ retains structural integrity, CaMnO₃ undergoes irreversible structural changes at low potentials, associated with the collapse of the perovskite framework. Intermediate compositions show partially reversible structural behavior. This decoupling of redox reversibility and structural instability, a picture only accessible through the use of XAS and XES, provides critical insight into the complex behavior of these materials under operational conditions. Additionally, our analysis shows that Mn-(II) formation is only detected in CaMnO₃ at potentials more negative than 0.4 V (vs RHE). The ORR onset is associated with Mn-(IV) reduction, while peroxide formation correlates with an increased Mn-(III)/Mn-(IV) ratio, supporting a 2e^- + 2e^- reduction pathway. This study demonstrates the power of XAS and XES analyses to disentangle electronic and structural dynamics, providing a more complete understanding of activity-stability relationships in perovskite electrocatalysts.</p>","PeriodicalId":520400,"journal":{"name":"ACS electrochemistry","volume":"2 5","pages":"1190-1196"},"PeriodicalIF":0.0,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13158912/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147936480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonequilibrium Electrical Double Layer Effects on Unilateral Peak Suppression in Cyclic Voltammetry.","authors":"Yupeng Qin, Zhangquan Peng, Jun Huang","doi":"10.1021/acselectrochem.5c00491","DOIUrl":"10.1021/acselectrochem.5c00491","url":null,"abstract":"<p><p>While equilibrium electrical double layer (EDL) effects on steady-state voltammetry have been studied, nonequilibrium transient EDL effects on cyclic voltammetry (CV) remain less understood. Herein, we report a combined theoretical and experimental study of nonequilibrium EDL effects on CV, focusing on their unequal influence over the cathodic and anodic peaks. The experiments are analyzed with the aid of a theoretical model coupling the Poisson-Nernst-Planck (PNP) theory and various electrode kinetic theories that can describe interfacial electron transfer reaction, EDL formation, and macroscopic mass transport in a unified framework. Consistent with experiments, the model predicts suppressed cathodic peaks for the CV of the [Fe-(CN)₆]^3-/4- redox reaction and correlates them with the spatiotemporal distributions of electrical potential and reactant concentration in the EDL. The model is then utilized as an efficient computational tool for exploration in the vast parametric space, identifying parametric regions where pronounced nonequilibrium EDL effects could be observed in CV. A regime diagram of nonequilibrium EDL effects on CV is calculated and validated partly with experiments. In general, the unilateral suppression of CV peaks is more pronounced when the reactive ion is repelled from the like-charged electrode surface at a higher scanning rate.</p>","PeriodicalId":520400,"journal":{"name":"ACS electrochemistry","volume":"2 5","pages":"1148-1160"},"PeriodicalIF":0.0,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13158924/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147936774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rationalized Volcano Plot in Heterogeneous Electrochemiluminescence.","authors":"Alessandro Fracassa, Michele Orza, Chiara Mariani, Claudio Ignazio Santo, Claudia Martinez Asenjo, Elisa D'Arrigo, Neso Sojic, Francesco Paolucci, Fabrizia Negri, Giovanni Valenti","doi":"10.1021/acselectrochem.6c00072","DOIUrl":"10.1021/acselectrochem.6c00072","url":null,"abstract":"<p><p>The performance of electrochemically induced chemiluminescence (ECL) assays strongly depends on the stability of electrogenerated coreactant radicals, which governs the spatial extension of the ECL emitting layer. This dependence is even more pronounced for heterogeneous bead-based ECL, where the emission efficiency is widely assumed to scale proportionally with the thickness of the ECL emitting layer. To date, however, establishing a consistent relationship between ECL intensity and radical stability has remained elusive: apparent rate constants fail to isolate intrinsic deprotonation kinetics, and the rational design of amines with long-lived radical cations remains experimentally challenging. In this work, using ECL microscopy, we address both issues by correlating the ECL intensity from individual [Ru-(bpy)₃]²⁺-labeled beads with the intrinsic deprotonation kinetics of model electrogenerated radical cations, including a novel long-lived intermediate arising from an aniline derivative. Kinetic constants derived from density functional theory (DFT) calculations, in the framework of a hybrid cluster-continuum approach, disentangled intrinsic radical decomposition rates from experimental artifacts such as concentration, pH, and buffer effects. This combined electrochemical imaging and computational approach reveals a non-monotonic, volcano-type dependence between the deprotonation rate of radical cations and ECL intensity, defining an optimal stability window for efficient ECL emission.</p>","PeriodicalId":520400,"journal":{"name":"ACS electrochemistry","volume":"2 5","pages":"1324-1332"},"PeriodicalIF":0.0,"publicationDate":"2026-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13159797/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147936963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Role of Local pH in Electrocatalysis: Measurement, Impact, and Control Strategies.","authors":"John W Rodriguez-Acosta, Ane Etxebarria, P V Sruthibhai, Sara Barja, Federico Calle-Vallejo, Max García-Melchor, Paramaconi Rodriguez","doi":"10.1021/acselectrochem.5c00489","DOIUrl":"10.1021/acselectrochem.5c00489","url":null,"abstract":"<p><p>The local pH at the electrode-electrolyte interface exerts a profound, yet often underappreciated, influence on the kinetics, selectivity, and stability of electrocatalytic reactions. This review critically examines the origins, dynamics, and consequences of pH gradients in processes such as water electrolysis, CO₂ reduction, nitrate reduction, and alcohol oxidation. We survey state-of-the-art experimental and computational approaches for probing local pH, including scanning electrochemical microscopy, operando spectroscopy, density functional theory, and multiscale modeling. These complementary methods reveal how near-surface (local) pH evolves with current density, electrode morphology, and electrolyte composition, thereby reshaping catalytic pathways and shifting reaction mechanisms. Particular attention is devoted to the influence of local pH on catalyst degradation and support corrosion, including phase dissolution, carbon oxidation, and membrane failure. We also discuss mitigation strategies such as buffer optimization, electrode architecture design, and gas diffusion layer engineering that enable control over local reaction environments. By integrating mechanistic insight with advanced diagnostics, this review highlights that controlling local pH is essential for improving both performance and durability in electrochemical systems. The concepts presented herein provide a framework for designing next-generation catalysts and reactors capable of operating under extreme or fluctuating (local) pH conditions.</p>","PeriodicalId":520400,"journal":{"name":"ACS electrochemistry","volume":"2 5","pages":"1055-1088"},"PeriodicalIF":0.0,"publicationDate":"2026-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13158913/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147936976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of Subsecond Estradiol Detection through Analysis of Surface-Analyte Interactions.","authors":"Moriah E Weese-Myers, Vivek Subedi, Naimah El-Amin, Faith Idahosa, Manisha Fowler, Ashley E Ross","doi":"10.1021/acselectrochem.6c00007","DOIUrl":"10.1021/acselectrochem.6c00007","url":null,"abstract":"<p><p>Subsecond neurochemical signaling is the fastest and one of the most diverse forms of intercellular communication employed along the neuro-immune-endocrine axis; consequently, spatiotemporally resolved approaches with high sensitivity and selectivity tailored to specific analytes are required for adequate monitoring. However, many existing electrochemical approaches are optimized solely towards catecholamine and indolamine detection, leaving a wide array of structurally diverse neuroregulators at a disadvantage with limited detection capability. Here, we use estradiola fast-signaling neurosteroid vital for neuroprotection that has proven difficult to detect with existing methodsas a model target analyte for optimizing direct electrochemical detection at carbon surfaces. We take a two-pronged approach to optimizing estradiol detection by examining the electrode-analyte interface from the perspective of both the carbon surface and the target molecule. We first establish the surface characteristics of diverse carbon fibers, then examine estradiol's electrochemical behavior at each surface. Finally, we determine the contributions of estradiol's structure to specific adsorption, elucidating subtle structural considerations to analyte-specific tailoring of carbon electrodes. By taking this multi-perspective approach, we develop a thorough understanding of the interactions between carbon sensing surfaces and estradiol for improved sensitivity and selectivity. Moreover, our approach is applicable to other neglected neurochemicals that have proven challenging to detect. This work creates a potentially broadly applicable roadmap for customizing direct monitoring at carbon surfaces through a tailored approach to optimizing the electrode-analyte interface.</p>","PeriodicalId":520400,"journal":{"name":"ACS electrochemistry","volume":"2 5","pages":"1262-1272"},"PeriodicalIF":0.0,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13158911/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147936838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive Lithium Polysulfide Diffusion Insights within Solid-State Electrolytes.","authors":"Marcela de Paula Ramos, Oier Pajuelo-Corral, Nicolas Goujon, Didier Devaux, Irune Villaluenga","doi":"10.1021/acselectrochem.5c00547","DOIUrl":"10.1021/acselectrochem.5c00547","url":null,"abstract":"<p><p>Lithium-sulfur (Li-S) batteries are highly attractive for next-generation energy storage applications due to their low cost, high theoretical energy density, and environmental benefits (nontoxicity, reducing reliance on rare metals, etc.). However, the implementation of Li-S batteries in the current battery manufacturing lines is hindered by the polysulfide dissolution and migration from cathode to anode through the liquid electrolyte, leading to irreversible capacity fading, poor Coulombic efficiency, and therefore limited battery lifetime. Replacing liquid electrolytes with solid-state electrolytes is the most promising approach to overcome the polysulfide migration challenge in lithium-sulfur (Li-S) batteries. Nevertheless, a fundamental understanding of the mechanisms governing polysulfide diffusion and the development of effective mitigation strategies are crucial. This perspective aims to provide a detailed overview of polysulfide diffusion mechanisms in solid-state electrolytes based on inorganic, polymer, and hybrid materials for Li-S battery applications. Examples of the challenges associated with polysulfide migration and the mitigation strategies employed in each solid electrolyte are provided. These strategies are focused on protective coatings, chemical modifications, advanced sintering techniques, material design, and computational modeling. Moreover, the relevance of advanced characterization techniques (such as XAS and XPS) to elucidate the complex polysulfide dissolution mechanisms occurring in solid electrolytes is highlighted. The insights presented here provide a critical foundation for future research development of efficient and high-performance solid-state Li-S battery devices.</p>","PeriodicalId":520400,"journal":{"name":"ACS electrochemistry","volume":"2 4","pages":"785-800"},"PeriodicalIF":0.0,"publicationDate":"2026-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13051556/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147635534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond Interfacial Structure: Ion Transport Mediates Cation Effects in Electrochemical Nitrate Reduction.","authors":"Madeline A Murphy, Kara D Fong","doi":"10.1021/acselectrochem.5c00534","DOIUrl":"10.1021/acselectrochem.5c00534","url":null,"abstract":"<p><p>Electrochemical reduction of nitrate to ammonia integrates wastewater nitrate remediation with sustainable ammonia production. Electrolyte engineering has revealed that the rate of nitrate reduction is sensitive to the identity of the supporting cation, increasing along Li⁺ < Na⁺ < K⁺ < Cs⁺. However, atomistic-level analysis of interfacial structure and mass transport across different electrolytes remains limited, leaving open questions about the physical origins of these specific ion effects. To address this gap, here we use classical molecular dynamics simulations in the constant potential ensemble to model the electric double layer in nitrate-based electrolytes. We assess the conventional hypotheses invoking cation-specific interfacial structure for successful nitrate adsorption and consider diffusion-layer mass transport as an additional origin of specific-ion rate enhancement. While the interfacial structure of the electrolyte is indeed cation-dependent, the thermodynamics of nitrate physisorption are, surprisingly, weakly dependent on the cation identity, as the interfacial electrostatic potential is dominated by water polarization, rather than cation adsorption. Analysis of bulk ion transport reveals that larger cations promote a lower nitrate transference number, reducing the energetic penalty for nitrate migration against the electric field. Combined with increased electrolyte diffusivity, this effect enhances the flux of nitrate to the cathode, following the same rate enhancement trend recorded in experiment. Our results demonstrate the importance of ion transport for electrochemical nitrate reduction and demonstrate how electrolyte design can be strategically leveraged to control reactant transport in the electric double layer.</p>","PeriodicalId":520400,"journal":{"name":"ACS electrochemistry","volume":"2 4","pages":"983-994"},"PeriodicalIF":0.0,"publicationDate":"2026-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13051559/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147635489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Slow Scan Cyclic Voltammetry of Li-Ion Insertion in T‑Nb₂O₅ Reveals Hidden Peaks and Multi-Electron Redox.","authors":"Luke D Salzer, Cami Christensen, Claire Gervais, Jacob D Steeley, James R Neilson, Justin B Sambur","doi":"10.1021/acselectrochem.5c00533","DOIUrl":"10.1021/acselectrochem.5c00533","url":null,"abstract":"<p><p>The orthorhombic phase of Nb₂O₅ formed at low temperatures (T-Nb₂O₅) is a promising alternative anode material for lithium-ion batteries due to its ability to reversibly (de)-lithiate at high rates without forming lithium metal, which is a major safety limitation of conventional graphite anodes. Despite decades of research, the cyclic voltammetry response of T-Nb₂O₅ remains poorly understood, with conflicting reports regarding the number and peak potentials of cathodic and anodic redox peaks in the voltammogram. While some studies report a single broad redox feature in cyclic voltammograms, others observe multiple peaks, yet often describe lithiation using a single overall reaction: T-Nb₂O₅ + <i>x</i>Li⁺ + <i>xe</i> ^-↔T-Li _<i>x</i> Nb₂O₅ for 0 < <i>x</i> < 2. For <i>x</i> = 2, Li insertion is accompanied by single-electron reduction of each Nb center (Nb⁵⁺ → Nb⁴⁺). In this work, we employ slow-scan cyclic voltammetry (SSCV) at an ultraslow rate of 1.5 μV/s to minimize resistive losses and kinetic limitations in the oxide. Under these near-equilibrium conditions, we achieve <i>x</i> = 3.0 in T-Li _<i>x</i> Nb₂O₅ from 3.0-1.2 V, corresponding to more than one electron per Nb center, and resolve five distinct cathodic peaks during lithiation. Three broad peaks are assigned to structural transformations based on recent literature <i>in situ</i> synchrotron-based X-ray diffraction data [HanH., . Nat. Mater.2023, 22-(9), 1128-1135.]: an orthorhombic-to-monoclinic distortion at <i>x</i> ≈ 0.5, followed by transitions to an amorphous insulating phase, and a tetragonal Li-rich layered rock salt structure at <i>x =</i> 2.0 and <i>x</i> = 2.5, respectively. In addition, two sharp peaks at 1.678 and 1.658 V, which merge into a single \"super peak\" at faster sweep rates (>100 μV/s), are attributed to surface-related electrochemical processes such as Nb reduction and Li-ion adsorption, surface phase transitions, or impurity B-Nb₂O₅. These features, widely observed in the literature but previously unassigned, underscore how electrode architecture (particles vs thin films), morphology, and scan rate conditions shape the voltammetric signature of T-Nb₂O₅. By employing ultraslow scan rates to suppress kinetic limitations and ohmic losses, we reveal previously hidden cathodic features in the cyclic voltammograms and directly correlate them with recently reported in situ structural phase transitions.</p>","PeriodicalId":520400,"journal":{"name":"ACS electrochemistry","volume":"2 4","pages":"974-982"},"PeriodicalIF":0.0,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13051442/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147635613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Catalyst-Coated Mesoporous Carbon-Membrane Electrode Assembly for In Situ Soft X‑ray XPS and NEXAFS Studies of Electrocatalytic Interfaces.","authors":"James J C Counter, Santosh Kumar, Christopher M Zalitis, Mark Clapp, Alexander I Large, David C Grinter, Matthijs A van Spronsen, Pilar Ferrer, Burcu Karagoz, Tugce Eralp Erden, Roger A Bennett, Georg Held","doi":"10.1021/acselectrochem.5c00554","DOIUrl":"10.1021/acselectrochem.5c00554","url":null,"abstract":"<p><p>In situ soft X-ray spectroscopy provides direct insight into the electronic structure of electrocatalysts under realistic reaction conditions but remains technically challenging due to the need to combine aqueous electrochemistry with ultra-high-vacuum detection. Here, we present a mesoporous carbon-membrane working electrode assembly (WEA) that enables window-free in situ XPS and NEXAFS measurements during electrochemical reactions. The design integrates a Nafion proton-exchange membrane with a mesoporous carbon-ionomer contact layer and a thin IrO _<i>x</i> catalyst layer, providing continuous electronic and protonic pathways and stable hydration through the membrane. By tuning the chamber water vapor pressure to 8 mbar, the WEA maintains a nanometer-thin water layer sufficient for the oxygen evolution reaction (OER) while preserving photoelectron detection efficiency. A robust peristaltic pump integrated with an alumina-bed water vapor dosing system maintains steady-state hydration at 6-10 mbar with <±0.1 mbar variation, enabling reproducible in situ spectra over extended periods. In situ Ir 4f and O 1s XPS reveal oxidation of Ir³⁺/Ir⁴⁺ to Ir⁴⁺/Ir⁵⁺ and dynamic changes in hydroxyl and lattice oxygen species, while O K-edge NEXAFS identify the formation of potential-stabilized μ₂-O and μ₁-O oxygen ligand species at OER. The WEA thus provides a quantitative, window-free platform for probing electrochemical interfaces under near-ambient conditions and establishes a general methodology for in situ soft X-ray studies of functional electrocatalysts, closely resembling the architecture and operation of industrial membrane-based water electrolyzers. This approach establishes a reliable methodology for coupling electrochemistry with the element specific soft X-ray spectroscopy under realistic reaction conditions.</p>","PeriodicalId":520400,"journal":{"name":"ACS electrochemistry","volume":"2 5","pages":"1226-1237"},"PeriodicalIF":0.0,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13158919/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147937133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling the Double Layer of Polycrystalline Electrodes: Capacitance, Potential of Zero Charge, and Parsons-Zobel Plot.","authors":"Jinwen Liu, Katharina Doblhoff-Dier, Marc T M Koper","doi":"10.1021/acselectrochem.5c00544","DOIUrl":"10.1021/acselectrochem.5c00544","url":null,"abstract":"<p><p>The double layer capacitance is a central tool to gain insight into the electrical double layer (EDL), yet its interpretation remains challenging. This is true in particular in the presence of surface heterogeneity and specific adsorption. Using a mean-field model, we discuss how these factors shape capacitance curves, affect the potential of zero charge (PZC), and alter the Parsons-Zobel (PZ) plots. The model reveals four distinct regimes of interfacial capacitance behaviour, determined by the facet size and ratio, the Debye length, and differences in PZC and Helmholtz capacitance between facets. These regimes define clear conditions under which capacitance curves exhibit either one or two minima, with the single minimum either coinciding with or deviating from the global PZC. We further demonstrate how adsorption on low-coordinated facets modifies the symmetry and magnitude of capacitance profiles and suppresses PZ slopes. Overall, this work provides a simple yet useful theoretical basis for recognizing and disentangling the respective roles of surface heterogeneity and adsorption in the EDL of polycrystalline electrodes, aiding in the interpretation of experimental results.</p>","PeriodicalId":520400,"journal":{"name":"ACS electrochemistry","volume":"2 4","pages":"995-1004"},"PeriodicalIF":0.0,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13051447/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147635507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}