ACS Combinatorial Science最新文献

{"title":"Circumventing Kinetic Barriers to Metal Hydride Formation with Metal–Ligand Cooperativity","authors":"Charlotte L. Montgomery,&nbsp;Mehmed Z. Ertem,&nbsp;Leo Chevalier and Jillian L. Dempsey*,&nbsp;","doi":"10.1021/jacs.4c0171610.1021/jacs.4c01716","DOIUrl":"https://doi.org/10.1021/jacs.4c01716https://doi.org/10.1021/jacs.4c01716","url":null,"abstract":"<p >We report the two-electron, one-proton mechanism of cobalt hydride formation for the conversion of [Co^IIICp(P^Ph₂N^Bn₂)(CH₃CN)]²⁺ to [HCo^IIICp(P^Ph₂N^Bn₂)]⁺. This complex catalytically converts CO₂ to formate under CO₂ reduction conditions, with hydride formation as a key elementary step. Through a combination of electrochemical measurements, digital simulations, theoretical calculations, and additional mechanistic and thermochemical studies, we outline the explicit role of the P^Ph₂N^Bn₂ ligand in the proton-coupled electron transfer (PCET) reactivity that leads to hydride formation. We reveal three unique PCET mechanisms, and we show that the amine on the P^Ph₂N^Bn₂ ligand serves as a kinetically accessible protonation site en route to the thermodynamically favored cobalt hydride. Cyclic voltammograms recorded with proton sources that span a wide range of p<i>K</i>_a values show four distinct regimes where the mechanism changes as a function of acid strength, acid concentration, and timescale between electrochemical steps. Peak shift analysis was used to determine proton transfer rate constants where applicable. This work highlights the astute choices that must be made when designing catalytic systems, including the basicity and kinetic accessibility of protonation sites, acid strength, acid concentration, and timescale between electron transfer steps, to maximize catalyst stability and efficiency.</p>","PeriodicalId":14,"journal":{"name":"ACS Combinatorial Science","volume":"146 44","pages":"30020–30032 30020–30032"},"PeriodicalIF":14.4,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142585768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pyrene-Functionalized Ru-Catenated Metallacycles: Conversion of Catenated System to Monorectangle through Aging","authors":"Gajendra Gupta*,&nbsp;Junseong Lee,&nbsp;Rizky Hadiputra,&nbsp;Jaehoon Jung,&nbsp;Peter J. Stang* and Chang Yeon Lee*,&nbsp;","doi":"10.1021/jacs.4c0928210.1021/jacs.4c09282","DOIUrl":"https://doi.org/10.1021/jacs.4c09282https://doi.org/10.1021/jacs.4c09282","url":null,"abstract":"<p >Molecular transformation behavior within a mechanically interlocked system is often assisted by chemical manipulation, such as the inclusion of guest molecules, variation in the solution concentration, or swapping of solvents. We present in this report the synthesis of ruthenium metal and π-conjugated pyrene-based (2 + 2)₂ catenated rectangles. Additionally, we discuss the structural conversion of these catenated rectangles into monorectangles through adjustments in concentration and solvent composition. In the presence of a methanol solution, a transformation into monorectangles was observed as the concentration declined. However, interestingly, in the presence of a nitromethane solution, an alteration in conformation to monorectangles was noted by just standing at room temperature for a few hours without any chemical manipulation. Furthermore, theoretical calculations were studied to provide insights into the formation of catenated structures over other potential ring-in-ring or Borromean-ring-type structures. The computational study with the GFN2-xTB method combined with density functional theory (DFT) calculations showed that the lower binding energy within the rectangles favors a catenated structure over other potential ring-in-ring or Borromean-ring-type structures. This work represents a new example of an intertwined structure that self-assembles into a catenated ring rather than a ring-in-ring or Borromean ring and transforms into a monorectangle in nitromethane without the use of any template, alteration in solution concentration, or exchange of solvents, but simply by standing at room temperature.</p>","PeriodicalId":14,"journal":{"name":"ACS Combinatorial Science","volume":"146 44","pages":"30222–30230 30222–30230"},"PeriodicalIF":14.4,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142585932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regio- and Enantioselective Nickel-Catalyzed Ipso- and Remote Hydroamination Utilizing Organic Azides as Amino Sources for the Synthesis of Primary Amines","authors":"Shi-Chao Wang,&nbsp;Lin Liu,&nbsp;Mei Duan,&nbsp;Weijia Xie,&nbsp;Jiabin Han,&nbsp;Yuhang Xue,&nbsp;You Wang,&nbsp;Xiaotai Wang* and Shaolin Zhu*,&nbsp;","doi":"10.1021/jacs.4c1232410.1021/jacs.4c12324","DOIUrl":"https://doi.org/10.1021/jacs.4c12324https://doi.org/10.1021/jacs.4c12324","url":null,"abstract":"<p >Primary amines serve as key synthetic precursors to most other <i>N</i>-containing compounds, which are important in organic and medicinal chemistry. Herein, we present a NiH-catalyzed mild ipso- and remote hydroamination technique that utilizes organic azides as deprotectable primary amine sources. This strategy offers a highly flexible platform for the efficient construction of α-chiral branched primary amines, as well as linear primary amines.</p>","PeriodicalId":14,"journal":{"name":"ACS Combinatorial Science","volume":"146 44","pages":"30626–30636 30626–30636"},"PeriodicalIF":14.4,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142585661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction to “pH Affects the Spontaneous Formation of H2O2 at the Air–Water Interfaces”","authors":"Maria Angelaki,&nbsp;Jil d’Erceville,&nbsp;D. James Donaldson and Christian George*,&nbsp;","doi":"10.1021/jacs.4c1421110.1021/jacs.4c14211","DOIUrl":"https://doi.org/10.1021/jacs.4c14211https://doi.org/10.1021/jacs.4c14211","url":null,"abstract":"","PeriodicalId":14,"journal":{"name":"ACS Combinatorial Science","volume":"146 44","pages":"30715 30715"},"PeriodicalIF":14.4,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/jacs.4c14211","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142585769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Annulated 1,4-Disilabenzene-1,4-diide and Dihydrogen Splitting","authors":"Falk Ebeler,&nbsp;Yury V. Vishnevskiy,&nbsp;Beate Neumann,&nbsp;Hans-Georg Stammler,&nbsp;Dariusz W. Szczepanik and Rajendra S. Ghadwal*,&nbsp;","doi":"10.1021/jacs.4c1212710.1021/jacs.4c12127","DOIUrl":"https://doi.org/10.1021/jacs.4c12127https://doi.org/10.1021/jacs.4c12127","url":null,"abstract":"<p >The isolation of silicon analogues of phenyl anions such as (C₆H₅)⁻ and (C₆H₄)^2– is challenging owing to their extremely high reactivity associated with their silylene character and weak C–Si π-interaction. Herein, we report the first annulated 1,4-disilabenzene-1,4-diide compound [(ADC)Si]₂ (<b>5</b>) based on anionic dicarbene (ADC) scaffolds (ADC = PhC{N(Dipp)C}₂; Dipp = 2,6-<i>i</i>Pr₂C₆H₃) as a green-yellow crystalline solid. Compound <b>5</b> is prepared by KC₈ reduction of the Si(IV) chloride [(ADC)SiCl₃]₂ (<b>3</b>) or the cyclic bis-chlorosilylene [(ADC)SiCl]₂ (<b>4</b>), which are also prepared for the first time. <b>5</b> is a neutral molecule, and each of the two-coordinated Si(I) atoms has a lone pair and an unpaired electron. Experimental and theoretical data indicate delocalization of the silicon unpaired electrons, resulting in a 6π-electron C₄Si₂ ring in <b>5</b>. The diradical character (<i>y</i>) for <b>5</b> amounts to 15%. At room temperature, <b>5</b> readily reacts with dihydrogen (H₂) to form the elusive bis-hydridosilylenes [(ADC)SiH]₂ (<i>Z</i>)-<b>6</b> and (<i>E</i>)-<b>6</b>. The [4 + 2]-cycloaddition of <b>5</b> and PhC≡CPh in yielding the barrelene-type bis-silylene [(ADC)SiCPh]₂ (<b>7</b>) emphasizes the diradical reactivity of <b>5</b>. With elemental sulfur, <b>5</b> results in the S₂- and S₃-bridged silathione derivatives [(ADC)Si(S)]₂(μ-S₂) (<b>8a</b>) and [(ADC)Si(S)]₂(μ-S₃) (<b>8b</b>). Moreover, the treatment of <b>5</b> with Fe₂(CO)₉ affords the Fe(0) complex [(ADC)Si(Fe(CO)₄)]₂(μ-CO) (<b>9</b>), in which each silicon atom serves as a two-electron σ-donor ligand and shares one electron with the bridging CO unit to form two Si–C bonds. The molecular structures of all compounds have been established by X-ray diffraction, and representative compounds have been analyzed by quantum chemical calculations.</p>","PeriodicalId":14,"journal":{"name":"ACS Combinatorial Science","volume":"146 44","pages":"30584–30595 30584–30595"},"PeriodicalIF":14.4,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142585660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pinwheel-like Curved Aromatics from the Cyclotrimerization of Strained Alkyne Cycloparaphenylenes","authors":"Tara D. Clayton,&nbsp;Julia M. Fehr,&nbsp;Tavis W. Price,&nbsp;Lev N. Zakharov and Ramesh Jasti*,&nbsp;","doi":"10.1021/jacs.4c1227210.1021/jacs.4c12272","DOIUrl":"https://doi.org/10.1021/jacs.4c12272https://doi.org/10.1021/jacs.4c12272","url":null,"abstract":"<p >Carbon nanomaterials composed of curved aromatics, such as carbon nanotubes, are difficult to selectively synthesize and modify precisely. Smaller molecular fragments of curved nanomaterials, such as cycloparaphenylenes, benefit from the precision of bottom-up synthesis, however, efforts to expand the curved molecular framework into even larger structures often rely on restrictive early stage synthetic strategies or difficult to control polymerizations. In this work we report a high yielding, strain-promoted, late-stage modification of a series of [<i>n</i> + 1]CPPs. We show that the conversion of these [<i>n</i> + 1]CPPs into soluble, pinwheel-like multipore carbon nanostructures is achievable via a straightforward and efficient metal-mediated alkyne cyclotrimerization reaction. We provide insight into suitable metals for this transformation, the photophysics of these trimeric molecules, as well as their strain profiles and crystal packing. We also demonstrate the strain-enhanced nature of the reaction under the optimized conditions, showing that strained internal-alkyne [<i>n</i> + 1]CPPs efficiently undergo complete conversion whereas unstrained diphenylacetylene remains completely unreacted. We anticipate that this work will have broader impacts on the study of reactivity in strained-alkyne-containing hydrocarbons, and that access to this new molecular architecture will inspire new research and applications in materials science and related fields.</p>","PeriodicalId":14,"journal":{"name":"ACS Combinatorial Science","volume":"146 44","pages":"30607–30614 30607–30614"},"PeriodicalIF":14.4,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142585936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrogen-Bond-Assisted Catalysis: Hydroxylation of Paclitaxel by Human CYP2C8","authors":"Dongxiao Yue,&nbsp;Elvis Wang Hei Ng and Hajime Hirao*,&nbsp;","doi":"10.1021/jacs.4c0793710.1021/jacs.4c07937","DOIUrl":"https://doi.org/10.1021/jacs.4c07937https://doi.org/10.1021/jacs.4c07937","url":null,"abstract":"<p >Paclitaxel (PTX, or Taxol), a chemotherapeutic agent widely employed in the treatment of various cancers, undergoes metabolic transformations through the cytochrome P450 enzymes CYP3A4 and CYP2C8. CYP3A4 catalyzes the aromatic hydroxylation reaction of PTX, whereas CYP2C8 demonstrates a distinct reactivity pattern, producing 6α-hydroxypaclitaxel via alkane hydroxylation. Despite the significant impact of PTX metabolism on its anticancer efficacy, the detailed mechanisms underlying these transformations have remained largely unclear. In this study, we employed hybrid quantum mechanics and molecular mechanics (QM/MM) calculations to elucidate the mechanism of PTX metabolism by human CYP2C8. Our QM/MM results reveal that the hydroxylation of PTX by CYP2C8 follows an atypical rebound mechanism. Either of the two hydrogen atoms at the C6 position of PTX can be abstracted, leading to a common radical intermediate. Although the subsequent rebound barrier is unusually high, stereochemical scrambling is unlikely, as the rebound barrier for the formation of the 6α-hydroxylated PTX─the actual product─is significantly lower than that for the 6β-hydroxylated metabolite. Thus, product selectivity is determined by the non-rate-determining rebound step. Furthermore, the hydroxyl group at the C7 position of PTX plays a catalytic role by facilitating the hydrogen abstraction and rebound steps. Our study also confirms a pronounced stability of the transition state in the high-spin sextet spin state, enabled by the enzyme’s specific substrate positioning.</p>","PeriodicalId":14,"journal":{"name":"ACS Combinatorial Science","volume":"146 44","pages":"30117–30125 30117–30125"},"PeriodicalIF":14.4,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/jacs.4c07937","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142585662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxygen Vacancy-Mediated Synthesis of Inter-Atomically Ordered Ultrafine Pt-Alloy Nanoparticles for Enhanced Fuel Cell Performance","authors":"Fantao Kong,&nbsp;Yifan Huang,&nbsp;Xu Yu,&nbsp;Min Li,&nbsp;Kunming Song,&nbsp;Qiuyun Guo,&nbsp;Xiangzhi Cui* and Jianlin Shi*,&nbsp;","doi":"10.1021/jacs.4c0718510.1021/jacs.4c07185","DOIUrl":"https://doi.org/10.1021/jacs.4c07185https://doi.org/10.1021/jacs.4c07185","url":null,"abstract":"<p >Pt-based intermetallics are expected to be the highly active catalysts for oxygen reduction reaction (ORR) in proton-exchange membrane fuel cells but still face great challenges in controllable synthesis of interatomically ordered and ultrafine intermetallic nanoparticles. Here, we propose an oxygen vacancy-mediated atomic diffusion strategy by mechanical alloying to reduce the energy barrier of the transition from interatomic disordering to ordering, and to resist interparticulate sintering via strong M–O–C bonding. This synthesis results in a nanosized core/shell structure featuring an interatomically ordered PtM core and a Pt shell of two to three atomic layers in thickness and can be extended to the multicomponent PtM (M = Co, FeCo, FeCoNi, FeCoNiGa) systems. The electron enrichment in the Pt outer shell induced by the compressive strain leads to the enhanced antibonding orbital occupation below the Fermi level and accelerated OH* desorption kinetics. The optimized PtCo–O/C-6 catalyst presents excellent ORR activity (mass activity = 1.28 A mg_Pt^–1 at 0.9 V_{<i>iR</i>-free}, peak power densities = 2.38/1.25 W cm^–2 in H₂–O₂/–air) and durability (∼1% activity loss in over 50 h in air condition) in fuel cells at a total Pt loading of 0.1 mg_Pt cm^–2. Furthermore, we establish a systematic correlation to elucidate the formation mechanisms of highly ordered intermetallic catalysts underlying oxygen vacancies. This study provides a general approach for the large-scale production of highly ordered and nanosized Pt-dispersed intermetallic catalysts.</p>","PeriodicalId":14,"journal":{"name":"ACS Combinatorial Science","volume":"146 44","pages":"30078–30090 30078–30090"},"PeriodicalIF":14.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142585506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"cis-Dihydroxylation by Synthetic Iron(III)–Peroxo Intermediates and Rieske Dioxygenases: Experimental and Theoretical Approaches Reveal the Key O–O Bond Activation Step","authors":"Peng Wu,&nbsp;Wenjuan Zhu,&nbsp;Yanru Chen,&nbsp;Zikuan Wang,&nbsp;Akhilesh Kumar,&nbsp;Binju Wang* and Wonwoo Nam*,&nbsp;","doi":"10.1021/jacs.4c0935410.1021/jacs.4c09354","DOIUrl":"https://doi.org/10.1021/jacs.4c09354https://doi.org/10.1021/jacs.4c09354","url":null,"abstract":"<p >Dioxygen (O₂) activation by iron-containing enzymes and biomimetic compounds generates iron–oxygen intermediates, such as iron-superoxo, -peroxo, -hydroperoxo, and -oxo, that mediate oxidative reactions in biological and abiological systems. Among the iron–oxygen intermediates, iron(III)–peroxo species are less frequently implicated as active intermediates in oxidation reactions. In this study, we present the combined experimental and theoretical investigations on <i>cis</i>-dihydroxylation reactions mediated by synthetic mononuclear nonheme iron–peroxo intermediates, demonstrating the importance of supporting ligands and metal centers in activating the peroxo ligand toward the O–O bond homolysis for the <i>cis</i>-dihydroxylation reactions. We found a significant ring size effect of the TMC ligand in [Fe^III(O₂)(<i>n</i>-TMC)]⁺ (TMC = tetramethylated tetraazacycloalkane; <i>n</i> = 12, 13, and 14) on the <i>cis</i>-dihydroxylation reactivity order: [Fe^III(O₂)(12-TMC)]⁺ &gt; [Fe^III(O₂)(13-TMC)]⁺ &gt; [Fe^III(O₂)(14-TMC)]⁺. Additionally, we found that only [Fe^III(O₂)(<i>n</i>-TMC)]⁺, but not other metal–peroxo complexes such as [M^III(O₂)(<i>n</i>-TMC)]⁺ (M = Mn, Co, and Ni), is reactive for the <i>cis</i>-dihydroxylation of olefins. Using density functional theory (DFT) calculations, we revealed that electron transfer from the Fe d_<i>xz</i> orbital to the peroxo σ*(O–O) orbital facilitates the O–O bond homolysis, with the O–O bond cleavage barrier well correlated with the energy gap between the frontier molecular orbitals of d_<i>xz</i> and σ*(O–O). Further computational studies showed that the reactivity of the synthetic [Fe^III(O₂)(12-TMC)]⁺ complex is comparable to that of Rieske dioxygenases in <i>cis</i>-dihydroxylation, providing compelling evidence of the potential involvement of Fe(III)–peroxo species in Rieske dioxygenases. Thus, the present results significantly advance our understanding of the <i>cis</i>-dihydroxylation mechanisms by Rieske dioxygenases and synthetic nonheme iron–peroxo models.</p>","PeriodicalId":14,"journal":{"name":"ACS Combinatorial Science","volume":"146 44","pages":"30231–30241 30231–30241"},"PeriodicalIF":14.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142585923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overcoming the Limitation of Ionomers on Mass Transport and Pt Activity to Achieve High-Performing Membrane Electrode Assembly","authors":"Fadong Chen,&nbsp;Lin Guo,&nbsp;Daojun Long,&nbsp;Shijian Luo,&nbsp;Yang Song,&nbsp;Meng Wang,&nbsp;Li Li,&nbsp;Siguo Chen* and Zidong Wei,&nbsp;","doi":"10.1021/jacs.4c1074210.1021/jacs.4c10742","DOIUrl":"https://doi.org/10.1021/jacs.4c10742https://doi.org/10.1021/jacs.4c10742","url":null,"abstract":"<p >The membrane electrode assembly (MEA) is one of the critical components in proton exchange membrane fuel cells (PEMFCs). However, the conventional MEA cathode with a covered-type catalyst/ionomer interfacial structure severely limits oxygen transport efficiency and Pt activity, hardly achieving the theoretical performance upper bound of PEMFCs. Here, we design a noncovered catalyst/ionomer interfacial structure with low proton transport resistance and high oxygen transport efficiency in the cathode catalyst layer (CL). This noncovered interfacial structure employs the ionomer cross-linked carbon particles as long-range and fast proton transport channels and prevents the ionomer from directly covering the Pt/C catalyst surface in the CL, freeing the oxygen diffusion process from passing through the dense ionomer covering layer to the Pt surface. Moreover, the structure improves oxygen transport within the pores of the CL and achieves more than 20% lower pressure-independent oxygen transport resistance compared to the covered-type structure. Fuel-cell diagnostics demonstrate that the noncovered catalyst/ionomer interfacial structure provides exceptional fuel-cell performance across the kinetic and mass transport-limited regions, with 77% and 67% higher peak power density than the covered-type interfacial structure under 0 kPa_gauge of oxygen and air conditions, respectively. This alternative interfacial structure provides a new direction for optimizing the electrode structure and improving mass-transport paths of MEA.</p>","PeriodicalId":14,"journal":{"name":"ACS Combinatorial Science","volume":"146 44","pages":"30388–30396 30388–30396"},"PeriodicalIF":14.4,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142585517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}