Search

Revealing the dynamic reconstruction process and tailoring advanced copper (Cu) catalysts is of paramount significance for promoting the conversion of CO2 into ethylene (C2H4), paving the way for carbon neutralization and facilitating renewable energy storage. In this study, we initially employed density functional theory (DFT) and molecular dynamics (MD) simulations to elucidate the restructuring behavior of a catalyst under electrochemical conditions and delineated its restructuring patterns. Leveraging insights into this restructuring behavior, we devised an efficient, low‐coordination copper‐based catalyst. The resulting synthesized catalyst demonstrated an impressive Faradaic efficiency (FE) exceeding 70 % for ethylene generation at a current density of 800 mA cm−2. Furthermore, it showed robust stability, maintaining consistent performance for 230 hours at a cell voltage of 3.5 V in a full‐cell system. Our research not only deepens the understanding of the active sites involved in designing efficient carbon dioxide reduction reaction (CO2RR) catalysts but also advances CO2 electrolysis technologies for industrial application. [ABSTRACT FROM AUTHOR]

Revealing the dynamic reconstruction process and tailoring advanced copper (Cu) catalysts is of paramount significance for promoting the conversion of CO2 into ethylene (C2H4), paving the way for carbon neutralization and facilitating renewable energy storage. In this study, we initially employed density functional theory (DFT) and molecular dynamics (MD) simulations to elucidate the restructuring behavior of a catalyst under electrochemical conditions and delineated its restructuring patterns. Leveraging insights into this restructuring behavior, we devised an efficient, low‐coordination copper‐based catalyst. The resulting synthesized catalyst demonstrated an impressive Faradaic efficiency (FE) exceeding 70 % for ethylene generation at a current density of 800 mA cm−2. Furthermore, it showed robust stability, maintaining consistent performance for 230 hours at a cell voltage of 3.5 V in a full‐cell system. Our research not only deepens the understanding of the active sites involved in designing efficient carbon dioxide reduction reaction (CO2RR) catalysts but also advances CO2 electrolysis technologies for industrial application. [ABSTRACT FROM AUTHOR]

Developing a high‐efficiency, stable, and CO‐toxicant‐resistant low‐cost hydrogen oxidation reaction (HOR) electrocatalyst is challenging but is vital for practical proton/anion exchange membrane fuel cells. Herein, an efficient pH‐universal HOR catalyst Pt1@Co1CN is fabricated, in which the electronic structure of single Pt sites is modulated by isolated Co atoms pre‐anchored on nitrogen‐doped carbon. Pt1@Co1CN exhibits superior HOR activity and durability under pH‐universal media than Pt1@CN (anchored single Pt atoms on nitrogen‐doped carbon) and commercial PtRu/C and Pt/C. More importantly, Pt1@Co1CN possesses much better CO anti‐poisoning ability than Pt1@CN and commercial PtRu/C and Pt/C. It is speculated that the superior pH‐universal HOR performance can be attributed to the inter‐regulation of adjacent Co and Pt sites, leading to the downshift of anti‐bonding state and consequently strengthening the *H adsorption, which promotes the kinetics of HOR. [ABSTRACT FROM AUTHOR]

Exploring efficient strategies to achieve novel high‐efficiency catalysts for water splitting is of great significance to develop hydrogen energy technology. Herein, unique molybdenum (Mo)‐doped ruthenium–cobalt oxide (Mo–RuCoOx) nanosheet arrays are prepared as a high‐performance bifunctional electrocatalyst toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) through combining electronic and vacancy engineering. Theoretical calculations and experimental results reveal that the incorporation of Ru and Mo can effectively tune the electronic structure, and the controllable Mo dissolution coupling with the oxygen vacancy generation during surface reconstruction is able to optimize the adsorption energy of hydrogen/oxygen intermediates, thus greatly accelerating the kinetics for both HER and OER. As a result, the Mo–RuCoOx nanoarrays exhibit remarkably low overpotentials of 41 and 156 mV at 10 mA cm−2 for HER and OER in 1 m KOH, respectively. Furthermore, the two‐electrode electrolyzer assembled by the Mo–RuCoOx nanoarrays requires a cell voltage as low as 1.457 V to achieve 10 mA cm−2 for alkaline overall water splitting. This work holds great promise to develop novel and highly active electrocatalysts for future energy conversion applications. [ABSTRACT FROM AUTHOR]

Highlights: Density functional theory calculations indicates that interstitial B atoms can tune the atomic spacing of host metal Os and achieve a reversal hydrogen adsorption-distance relationship. The structure–activity relationship between the spacing of active Os atoms and catalytic activity is established. Prepared OsB2 with increasing dOs-Os of 2.96 Å presents the optimal hydrogen evolution reaction activity (8 mV @ 10 mA cm−2) and robust stability in alkaline media. Precisely tuning the spacing of the active centers on the atomic scale is of great significance to improve the catalytic activity and deepen the understanding of the catalytic mechanism, but still remains a challenge. Here, we develop a strategy to dilute catalytically active metal interatomic spacing (dM-M) with light atoms and discover the unusual adsorption patterns. For example, by elevating the content of boron as interstitial atoms, the atomic spacing of osmium (dOs-Os) gradually increases from 2.73 to 2.96 Å. More importantly, we find that, with the increase in dOs-Os, the hydrogen adsorption-distance relationship is reversed via downshifting d-band states, which breaks the traditional cognition, thereby optimizing the H adsorption and H2O dissociation on the electrode surface during the catalytic process; this finally leads to a nearly linear increase in hydrogen evolution reaction activity. Namely, the maximum dOs-Os of 2.96 Å presents the optimal HER activity (8 mV @ 10 mA cm−2) in alkaline media as well as suppressed O adsorption and thus promoted stability. It is believed that this novel atomic-level distance modulation strategy of catalytic sites and the reversed hydrogen adsorption-distance relationship can shew new insights for optimal design of highly efficient catalysts. [ABSTRACT FROM AUTHOR]

Bismuth‐based materials have been recognized as promising catalysts for the electrocatalytic CO2 reduction reaction (ECO2RR). However, they show poor selectivity due to competing hydrogen evolution reaction (HER). In this study, we have developed an edge defect modulation strategy for Bi by coordinating the edge defects of bismuth (Bi) with sulfur, to promote ECO2RR selectivity and inhibit the competing HER. The prepared catalysts demonstrate excellent product selectivity, with a high HCOO− Faraday efficiency of ≈95 % and an HCOO− partial current of ≈250 mA cm−2 under alkaline electrolytes. Density function theory calculations reveal that sulfur tends to bind to the Bi edge defects, reducing the coordination‐unsaturated Bi sites (*H adsorption sites), and regulating the charge states of neighboring Bi sites to improve *OCHO adsorption. This work deepens our understanding of ECO2RR mechanism on bismuth‐based catalysts, guiding for the design of advanced ECO2RR catalysts. [ABSTRACT FROM AUTHOR]

Bismuth‐based materials have been recognized as promising catalysts for the electrocatalytic CO2 reduction reaction (ECO2RR). However, they show poor selectivity due to competing hydrogen evolution reaction (HER). In this study, we have developed an edge defect modulation strategy for Bi by coordinating the edge defects of bismuth (Bi) with sulfur, to promote ECO2RR selectivity and inhibit the competing HER. The prepared catalysts demonstrate excellent product selectivity, with a high HCOO− Faraday efficiency of ≈95 % and an HCOO− partial current of ≈250 mA cm−2 under alkaline electrolytes. Density function theory calculations reveal that sulfur tends to bind to the Bi edge defects, reducing the coordination‐unsaturated Bi sites (*H adsorption sites), and regulating the charge states of neighboring Bi sites to improve *OCHO adsorption. This work deepens our understanding of ECO2RR mechanism on bismuth‐based catalysts, guiding for the design of advanced ECO2RR catalysts. [ABSTRACT FROM AUTHOR]

Theoretical calculations unveil that the formation of Os‐OsSe2 heterostructures with neutralized work function (WF) perfectly balances the electronic state between strong (Os) and weak (OsSe2) adsorbents and bidirectionally optimizes the hydrogen evolution reaction (HER) activity of Os sites, significantly reducing thermodynamic energy barrier and accelerating kinetics process. Then, heterostructural Os‐OsSe2 is constructed for the first time by a molten salt method and confirmed by in‐depth structural characterization. Impressively, due to highly active sites endowed by the charge balance effect, Os‐OsSe2 exhibits ultra‐low overpotentials for HER in both acidic (26 mV @ 10 mA cm−2) and alkaline (23 mV @ 10 mA cm−2) media, surpassing commercial Pt catalysts. Moreover, the solar‐to‐hydrogen device assembled with Os‐OsSe2 further highlights its potential application prospects. Profoundly, this special heterostructure provides a new model for rational selection of heterocomponents. [ABSTRACT FROM AUTHOR]

Theoretical calculations unveil that the formation of Os‐OsSe2 heterostructures with neutralized work function (WF) perfectly balances the electronic state between strong (Os) and weak (OsSe2) adsorbents and bidirectionally optimizes the hydrogen evolution reaction (HER) activity of Os sites, significantly reducing thermodynamic energy barrier and accelerating kinetics process. Then, heterostructural Os‐OsSe2 is constructed for the first time by a molten salt method and confirmed by in‐depth structural characterization. Impressively, due to highly active sites endowed by the charge balance effect, Os‐OsSe2 exhibits ultra‐low overpotentials for HER in both acidic (26 mV @ 10 mA cm−2) and alkaline (23 mV @ 10 mA cm−2) media, surpassing commercial Pt catalysts. Moreover, the solar‐to‐hydrogen device assembled with Os‐OsSe2 further highlights its potential application prospects. Profoundly, this special heterostructure provides a new model for rational selection of heterocomponents. [ABSTRACT FROM AUTHOR]

Electrochemical 2‐electron oxygen reduction reaction (ORR) is a promising route for renewable and on‐site H2O2 production. Oxygen‐rich carbon nanotubes have been demonstrated their high selectivity (≈80%), yet tailoring the composition and structure of carbon nanotubes to further enhance the selectivity and widen working voltage range remains a challenge. Herein, combining formamide condensation coating and mild temperature calcination, a nitrogen and oxygen comodified carbon nanotubes (N,O‐CNTs) electrocatalyst is synthesized, which shows excellent selective (>95%) H2O2 selectivity in a wide voltage range (from 0 to 0.65 V versus reversible hydrogen electrode). It is significantly superior to the corresponding selectivity values of CNTs (≈50% in 0–0.65 V vs RHE) and O‐CNTs (≈80% in 0.3–0.65 V vs RHE). Density functional theory calculations revealed that the C neighbouring to N is the active site. Introducing O‐related species can strengthen the adsorption of intermediates *OOH, while N‐doping can weaken the adsorption of in situ generated *O and optimize the *OOH adsorption energy, thus improving the 2‐electron pathway. With optimized N,O‐CNTs catalysts, a Janus electrode is designed by adjusting the asymmetric wettability to achieve H2O2 productivity of 264.8 mol kgcat–1 h–1. [ABSTRACT FROM AUTHOR]

[Display omitted] Fe–N–C electrocatalysts, comprising FeN 4 single atom sites immobilized on N-doped carbon supports, offer excellent activity in the oxygen reduction reaction (ORR), especially in alkaline solution. Herein, we report a simple synthetic strategy for improving the accessibility of FeN 4 sites during ORR and simultaneously fine-tuning the microenvironment of FeN 4 sites, thus enhancing the ORR activity. Our approach involved a simple one-step pyrolysis of a Fe-containing zeolitic imidazolate framework in the presence of NaCl, yielding a hierarchically porous Fe–N–C electrocatalyst containing tailored FeN 4 sites with slightly elongated Fe–N bond distances and reduced Fe charge. The porous carbon structure improved mass transport during ORR, whilst the microenvironment optimized FeN 4 sites benefitted the adsorption/desorption of ORR intermediates. Accordingly, the developed electrocatalyst, possessing a high FeN 4 site density (9.9 × 1019 sites g−1) and turnover frequency (2.26 s−1), delivered remarkable ORR performance with a low overpotential (a half-wave potential of 0.90 V vs. reversible hydrogen electrode) in 0.1 mol L−1 KOH. [ABSTRACT FROM AUTHOR]

The trade-off effect between Li bond and S bond for anchoring polysulfides on 3d-transition metal doped BN towards the application in Lithium-sulfur battery. [Display omitted] • A trade-off effect is detected between TM-S and Li-N bonds for anchoring LiPSs/S 8. • A closer d -band center of TM-BN benefits the TM-S bond and weakens the Li-N bond. • A closer d -band center of TM-BN leads to a lower decomposition energy of Li 2 S. • DME/DOL electrolyte has a little effect on the adsorption of LiPSs/S 8 on TM-BN. • Ti/V/Cr-BN stands out from TM-BNs for use in LSB. Sulfur cathodes in lithium-sulfur batteries (LSBs) suffer from the notorious "shuttle effect", low sulfur use ratio, and tardy transformation of lithium polysulfides (LiPSs), while using two-dimensional (2D) polar anchoring materials combined with single-atom catalysis is one of the promising methods to address these issues. Herein, the 3 d transition metal (TM) doped 2D boron nitrides (BN), labeled as TM-BN, are studied for the anchoring and redox kinetics of LiPSs using first principles calculations. From the simulated results, the TM atom and adjacent N atoms are active adsorption sites for binding S atoms in LiPSs/S 8 and Li atoms in LiPSs, respectively. A negative d -band center closer to the Fermi level of TM-BN is key for enhancing the binding strength of TM-S and lowering the Li 2 S decomposition energy barrier, while it deteriorates the activity of adjacent N atoms. Fortunately, the electrolyte environment has little effect on the superiority of the TM-BN for binding polysulfides/S 8 , guaranteeing the sturdy anchor of polysulfides/S 8 in realistic conditions. The trade-off effect on the activities of TM and adjacent N atom sites in TM-BN for binding LiPSs highlights the excellence of Ti/V/Cr-BN as modification materials for LSB. [ABSTRACT FROM AUTHOR]

High‐performance transition metal chalcogenides (TMCs) as electrocatalysts for two‐electron oxygen reduction reaction (2e‐ORR) in alkaline medium are promising for hydrogen peroxide (H2O2) production, but their synthesis remains challenging. In this work, a titanium‐doped zinc–cobalt sulfide hollow superstructure (Ti–ZnCoS HSS) is rationally designed as an efficient electrocatalyst for H2O2 electrosynthesis. Synthesized by using hybrid metal–organic frameworks (MOFs) as precursors after sulfidation treatment, the resultant Ti–ZnCoS HSS exhibits a hollow‐on‐hollow superstructure with small nanocages assembled around a large cake‐like cavity. Both experimental and simulation results demonstrate that the polymetallic composition tailors the d‐band center and binding energy with oxygen species. Moreover, the hollow superstructure provides abundant active sites and promotes mass and electron transfer. The synergistic d‐band center and superstructure engineering at both atomic and nanoscale levels lead to the remarkable 2e‐ORR performance of Ti–ZnCoS HSS with a high selectivity of 98%, activity (potential at 1 mA cm−2 of 0.774 V vs reversible hydrogen electrode (RHE)), a H2O2 production rate of 675 mmol h–1 gcat–1, and long‐term stability in alkaline condition, among the best 2e‐ORR electrocatalysts reported to date. This strategy paves the way toward the rational design of polymetallic TMCs as advanced 2e‐ORR catalysts. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) production by electrochemical two‐electron water oxidation reaction (2e‐WOR) is a promising approach, where high‐performance electrocatalysts play critical roles. Here, the synthesis of nanostructured CaSnO3 confined in conductive carbon fiber membrane with abundant oxygen vacancy (OV) as a new generation of 2e‐WOR electrocatalyst is reported. The CaSnO3@carbon fiber membrane can be directly used as a self‐standing electrode, exhibiting a record‐high H2O2 production rate of 39.8 µmol cm−2 min−1 and a selectivity of ≈90% (at 2.9 V vs reversible hydrogen electrode). The CaSnO3@carbon fiber membrane design improves not only the electrical conductivity and stability of catalysts but also the inherent activity of CaSnO3. Density functional theory calculation further indicates the crucial role of OV in increasing the adsorption free energy toward oxygen intermediates associated with the competitive four‐electron water oxidation reaction pathway, thus enhancing the activity and selectivity of 2e‐WOR. The findings pave a new avenue to the rational design of electrocatalysts for H2O2 production from water. [ABSTRACT FROM AUTHOR]

Improving the catalytic performance of graphene for the electrochemical CO2 reduction reaction (CO2RR) has been a promising avenue to abate the concentration of greenhouse gas and develop a strategy of CO2 recyclable utilization. In this paper, we systematically investigate the catalytic performance of different active sites, both on the undoped and N‐doped graphene sheets, under non‐strained (0%) and 1%, 5% and 10% lattice strain (LS) via density functional theory calculations. The results uncover that N‐doping and LS synergistically modulate the electronic structures of graphene, enhancing the electrocatalytic reduction of CO2 to CO. Among all models in this work, the site with the highest catalytic activity toward CO2RR is shown to be the carbon atom at the ortho‐position (labeled as G2) relative to the nitrogen heteroatom (denoted by N1) on the graphene under 10% LS due to its lowest overpotential of 1.19 eV. Moreover, the projected density of states and the charge density differences of all systems are calculated to explore the mechanism for the enhancement of CO2 reduction performance. These analyses indicate that the localization of electron density on the G2 site makes it be the most active site on the N‐doped graphene sheet for CO2RR. Hence, our computations demonstrate that by both nitrogen doping and LS increasing on the graphene sheet is a promising way for positive modulating its catalytic activity of the CO2RR. [ABSTRACT FROM AUTHOR]

Keywords: bifunctional electrocatalysts; Mo doping; nanoarrays; vacancy engineering; water splitting EN bifunctional electrocatalysts Mo doping nanoarrays vacancy engineering water splitting 1 1 1 10/05/23 20231002 NES 231002 B Nanoarrays b In article number 2303073, Yan Zhao, Limin Qi, and co-workers construct unique Mo-doped ruthenium-cobalt oxide (Mo-RuCoO SB I x i sb ) nanosheet arrays as a bifunctional electrocatalyst for efficient HER and OER, achieving outstanding performance toward alkaline overall water splitting. Electronic and Vacancy Engineering of Mo-RuCoOx Nanoarrays for High-Efficiency Water Splitting (Adv. Funct. The combination of electronic and vacancy engineering through Mo-doping coupled with oxygen vacancy generation endows the Mo-RuCoO SB I x i sb nanoarrays with optimized electronic structure, desired adsorption energy of intermediates, and remarkably enhanced activity. [Extracted from the article]

Two linear relationships between the CO 2 /Li 2 CO 2 adsorption energies and the limiting potential accurately describe the overall performances toward Li-CO 2 evolution on the DACs. [Display omitted] • The results show that the transition metal atoms in M 1 M 2 NC(III) center sites with less d -orbital electrons show the superior interactions with CO 2 due to larger overlapping of d (TM) and p (oxygen) orbitals. This leads to the MnM 2 NC(III) and M 1 MoNC(III) center sites exhibit the stronger adsorption interaction with CO 2 than the rest of DACs. • We have verified that the multi-orbital interaction between d yz , d xz , d z 2 and the hybrid 2 p orbitals results in superior bonding interaction of CO 2 on DACs. Based on these orbital interactions, we have defined the relationship between adsorption energies and d band center of the DACs. • After further comparing and screening the limiting potentials of the overall reactions, two key descriptors were found by establishing the linear relationship between CO 2 /Li 2 CO 2 adsorption energies and the limiting potential , which can help accurately describe the overall performances toward Li-CO 2 evolution on the DACs. The development of highly efficient electrocatalysts and understanding the reaction mechanisms during the discharge and charge is essential for the designs of advanced Li-CO 2 batteries, but still remains a great challenge. Herein, by using first-principles density functional theory calculations, we systematically investigated the 21 types dual-atom catalysts (DACs), including homonuclear and heteronuclear transition-metal sites (M 1 M 2 NC, M 1 and M 2 are one of the Mo, Mn, Fe, Co, Ni, Cu elements), and studied the possible reaction mechanisms for Li-CO 2 batteries. Through the comparison of the adsorption energy and the orbital interactions, we have verified that the multi-orbital interactions between d yz , d xz , d z 2 orbitals of TMs and the hybrid 2 p orbitals of CO 2 result in superior bonding interaction of CO 2 on DACs. Furthermore, based on these orbital interactions, we found that the DACs with lower d center preferentially have higher CO 2 activation capability, and therefore defined the relationship between adsorption energies and d band centers. Accordingly, we confirmed that the two linear relationships between the CO 2 and Li 2 CO 2 adsorption energies and the limiting potential, which can accurately describe the overall performances toward Li-CO 2 evolution on the DACs. The correlations among CO 2 activation, orbital interactions and the catalytic performances obtained in this work pave a way for rational design of DACs for improving the efficiency of Li-CO 2 batteries. [ABSTRACT FROM AUTHOR]

Advancing the performance of the Cu‐catalyzed electrochemical CO2 reduction reaction (CO2RR) is crucial for its practical applications. Still, the wettable pristine Cu surface often suffers from low exposure to CO2, reducing the Faradaic efficiencies (FEs) and current densities for multi‐carbon (C2+) products. Recent studies have proposed that increasing surface availability for CO2 by cation‐exchange ionomers can enhance the C2+ product formation rates. However, due to the rapid formation and consumption of *CO, such promotion in reaction kinetics can shorten the residence of *CO whose adsorption determines C2+ selectivity, and thus the resulting C2+ FEs remain low. Herein, we discover that the electro‐kinetic retardation caused by the strong hydrophobicity of quaternary ammonium group‐functionalized polynorbornene ionomers can greatly prolong the *CO residence on Cu. This unconventional electro‐kinetic effect is demonstrated by the increased Tafel slopes and the decreased sensitivity of *CO coverage change to potentials. As a result, the strongly hydrophobic Cu electrodes exhibit C2+ Faradaic efficiencies of ≈90 % at a partial current density of 223 mA cm−2, more than twice of bare or hydrophilic Cu surfaces. [ABSTRACT FROM AUTHOR]

Advancing the performance of the Cu‐catalyzed electrochemical CO2 reduction reaction (CO2RR) is crucial for its practical applications. Still, the wettable pristine Cu surface often suffers from low exposure to CO2, reducing the Faradaic efficiencies (FEs) and current densities for multi‐carbon (C2+) products. Recent studies have proposed that increasing surface availability for CO2 by cation‐exchange ionomers can enhance the C2+ product formation rates. However, due to the rapid formation and consumption of *CO, such promotion in reaction kinetics can shorten the residence of *CO whose adsorption determines C2+ selectivity, and thus the resulting C2+ FEs remain low. Herein, we discover that the electro‐kinetic retardation caused by the strong hydrophobicity of quaternary ammonium group‐functionalized polynorbornene ionomers can greatly prolong the *CO residence on Cu. This unconventional electro‐kinetic effect is demonstrated by the increased Tafel slopes and the decreased sensitivity of *CO coverage change to potentials. As a result, the strongly hydrophobic Cu electrodes exhibit C2+ Faradaic efficiencies of ≈90 % at a partial current density of 223 mA cm−2, more than twice of bare or hydrophilic Cu surfaces. [ABSTRACT FROM AUTHOR]

One-step solvothermal method for the synthesis of highly entropic hydroxymethoxy compounds with lamellar structures. [Display omitted] • A new high entropy metal hydroxymethylate material (FeCoNiMgCr-HM) is synthesized. • A rule for guiding the synthesis of metal hydroxymethylate materials is proposed. • The activated electrocatalyst exhibits an outstanding OER performance. Much attention has been paid to high entropy materials in the field of electrochemical water splitting. In this research, we present a synthesis of a high-entropy metal hydroxymethylate FeCoNiMgCr(OH)(OCH 3) (labeled as FeCoNiMgCr-HM) material via a one-step solvothermal method. Due to the synergistic effect of five metal cations and complete surface reconstruction induced by methoxyl group, FeCoNiMgCr-HM after electrochemical activation exhibits an outstanding performance for catalyzing lattice-oxygen-participated OER with a low overpotential of 291 mV to reach a current density of 20 mA cm−2 and a small Tafel slope of 49.1 mV dec-1. In addition, we summarize a universal ionic potential rule for guiding the synthesis of metal hydroxymethylate materials. [ABSTRACT FROM AUTHOR]

Ruthenium (Ru) is considered a promising candidate catalyst for alkaline hydroxide oxidation reaction (HOR) due to its hydrogen binding energy (HBE) like that of platinum (Pt) and its much higher oxygenophilicity than that of Pt. However, Ru still suffers from insufficient intrinsic activity and CO resistance, which hinders its widespread use in anion exchange membrane fuel cells (AEMFCs). Here, we report a hybrid catalyst (RuCo)NC+SAs/N‐CNT consisting of dilute RuCo alloy nanoparticles and atomically single Ru and Co atoms on N‐doped carbon nanotubes The catalyst exhibits a state‐of‐the‐art activity with a high mass activity of 7.35 A mgRu−1. More importantly, when (RuCo)NC+SAs/N‐CNT is used as an anode catalyst for AEMFCs, its peak power density reaches 1.98 W cm−2, which is one of the best AEMFCs properties of noble metal‐based catalysts at present. Moreover, (RuCo)NC+SAs/N‐CNT has superior long‐time stability and CO resistance. The experimental and density functional theory (DFT) results demonstrate that the dilute alloying and monodecentralization of the exotic element Co greatly modulates the electronic structure of the host element Ru, thus optimizing the adsorption of H and OH and promoting the oxidation of CO on the catalyst surface, and then stimulates alkaline HOR activity and CO tolerance of the catalyst. [ABSTRACT FROM AUTHOR]

Ruthenium (Ru) is considered a promising candidate catalyst for alkaline hydroxide oxidation reaction (HOR) due to its hydrogen binding energy (HBE) like that of platinum (Pt) and its much higher oxygenophilicity than that of Pt. However, Ru still suffers from insufficient intrinsic activity and CO resistance, which hinders its widespread use in anion exchange membrane fuel cells (AEMFCs). Here, we report a hybrid catalyst (RuCo)NC+SAs/N‐CNT consisting of dilute RuCo alloy nanoparticles and atomically single Ru and Co atoms on N‐doped carbon nanotubes The catalyst exhibits a state‐of‐the‐art activity with a high mass activity of 7.35 A mgRu−1. More importantly, when (RuCo)NC+SAs/N‐CNT is used as an anode catalyst for AEMFCs, its peak power density reaches 1.98 W cm−2, which is one of the best AEMFCs properties of noble metal‐based catalysts at present. Moreover, (RuCo)NC+SAs/N‐CNT has superior long‐time stability and CO resistance. The experimental and density functional theory (DFT) results demonstrate that the dilute alloying and monodecentralization of the exotic element Co greatly modulates the electronic structure of the host element Ru, thus optimizing the adsorption of H and OH and promoting the oxidation of CO on the catalyst surface, and then stimulates alkaline HOR activity and CO tolerance of the catalyst. [ABSTRACT FROM AUTHOR]

Atomically precise supported nanocluster catalysts (APSNCs), which feature exact atomic composition, well‐defined structures, and unique catalytic properties, offer an exceptional platform for understanding the structure‐performance relationship at the atomic level. However, fabricating APSNCs with precisely controlled and uniform metal atom numbers, as well as maintaining a stable structure, remains a significant challenge due to uncontrollable dispersion and easy aggregation during synthetic and catalytic processes. Herein, we developed an effective ligand engineering strategy to construct a Pt6 nanocluster catalyst stabilized on oxidized carbon nanotubes (Pt6/OCNT). The structural analysis revealed that Pt6 nanoclusters in Pt6/OCNT were fully exposed and exhibited a planar structure. Furthermore, the obtained Pt6/OCNT exhibited outstanding acidic HOR performances with a high mass activity of 18.37 A ⋅ mgpt−1 along with excellent stability during a 24 h constant operation and good CO tolerance, surpassing those of the commercial Pt/C. Density functional theory (DFT) calculations demonstrated that the unique geometric and electronic structures of Pt6 nanoclusters on OCNT altered the hydrogen adsorption energies on catalytic sites and thus lowered the HOR theoretical overpotential. This work presents a new prospect for designing and synthesizing advanced APSNCs for efficient energy electrocatalysis. [ABSTRACT FROM AUTHOR]

Ru-NiCoP/NF, with a unique 3D flower-like structure was synthesized by Ru doping and subsequent phosphating derived from MOF, exhibiting both superior OER and HER activities and stabilities in alkaline media. • DFT calculation results unravel Ru-dopant has a climbing effect on OER and HER. • Bifunctional Ru-NiCoP/NF catalysts are prepared by a MOFs based route. • Unique 3D flower-like structures afford large surface area and more exposed sites. • Such a structure is useful to transfer/adsorption of electrons and water molecules. • An ultralow cell voltage and almost 100 % Faradaic yield for water splitting. The resplendent prospect of water splitting hydrogen production technology makes the development of efficient and stable hydrogen/oxygen evolution reactions (HER/OER) bifunctional catalysts become urgent. Herein, inspired by the density function theory (DFT) calculation result that Ru-dopants have a climbing effect on both OER and HER processes, we construct a Ru doped three-dimensional flower-like bimetallic phosphide on nickel foam (Ru-NiCoP/NF) derived from Co leaf-like zeolitic imidazolate framework (Co ZIF-L), effectively driving both OER (216mV@20 mA cm−2) and HER (44mV@10 mA cm−2) in 1 M KOH solutions. The overall water splitting device assembled by using Ru-NiCoP/NF as both anode and cathode shows an ultralow cell voltage of 1.515 V to obtain 10 mA cm−2. Interestingly, almost 100 % Faradic yield is achieved for the overall water splitting. This work represents a significant addition to exploring a new class of transition metal phosphides with outstanding performance in producing hydrogen via electrochemical water electrolysis. [ABSTRACT FROM AUTHOR]

Water splitting is a promising technology for sustainable conversion of hydrogen energy. The rational design of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) bifunctional electrocatalysts with superior activity and stability in the same electrolyte is the key to promoting their large‐scale applications. Herein, an ultralow Ru (1.08 wt%) transition metal phosphide on nickel foam (Ru–MnFeP/NF) derived from Prussian blue analogue, that effectively drivies both the OER and the HER in 1 m KOH, is reported. To reach 20 mA cm−2 for OER and 10 mA cm−2 for HER, the Ru–MnFeP/NF electrode only requires overpotentials of 191 and 35 mV, respectively. Such high electrocatalytic activity exceeds most transition metal phosphides for the OER and the HER, and even reaches Pt‐like HER electrocatalytic levels. Accordingly, it significantly accelerates full water splitting at 10 mA cm−2 with 1.470 V, which outperforms that of the integrated RuO2 and Pt/C couple electrode (1.560 V). In addition, the extremely long operational stability (50 h) and the successful demonstration of a solar‐to‐hydrogen generation system through full water splitting provide more flexibility for large‐scale applications of Ru–MnFeP/NF catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Artificial defect-rich MoN/Ni@C heterointerface was constructed by ion exchange. • The MoN/Ni@C catalyst deivers superior HER performance (27 mV@10 mA cm−2). • DFT calculation reveals the mechanism of HER of defect-rich heterointerface. Developing highly-active and robust electrocatalysts for the hydrogen evolution reaction (HER) is extremely desirable for hydrogen production but remains highly challenging. Herein, we reported a rational strategy to fabricate a novel metallic heterostructure composed of defect-rich nickel and amorphous/crystalline molybdenum nitride anchored on a carbon matrix (MoN/Ni@C) as a superior HER electrocatalyst. Owing to the electronic structural modulation of the interfacial synergy of the defects and phase engineering, the MoN/Ni@C exhibits a low HER overpotential of 27 mV at 10 mA cm−2 and a small Tafel slope of 73 mV dec−1 in 1.0 M KOH solution, without any distinct attenuation after 180 h of operation. Density functional theory calculation results demonstrate that the interfacial electron transfer leads to a distorted Ni surface incorporation of the MoN phase, achieving the optimal thermoneutral hydrogen adsorption free energies (ΔG *H) of Mo and Ni active sites. Meanwhile, the amorphous/crystalline structure in the MoN phase exposes more active sites and promotes structural stability. This work provides new insights into designing heterogeneous interfaces of non-noble-metal-based electrocatalysts with superior HER activities. [ABSTRACT FROM AUTHOR]

Despite their potential as electrocatalysts, the catalytic mechanisms of main-group single-atom catalysts (MSACs) remain largely unexplored. To address this knowledge gap, we conducted a series of first-principles calculations to investigate a repertoire of MSACs that incorporated 17 active main-group atoms and 8 carbon supports, systematically screening the optimal catalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) via activity-adsorption scaling relations. Our findings reveal that as the single-atom in MSACs moves down the periodic table, their adsorption capabilities become even more enhanced. Moreover, MSACs derived from the fifth and sixth periods exhibit mild adsorption capabilities and robust catalytic activity. In addition, our study identifies a linear correlation between the adsorption energy of *OH intermediates, the p -band center, and the electronegativity of the main-group atom in MSACs, serving as an efficacious ORR activity descriptor and allowing for the prediction of novel catalysts. Our analysis further illuminated two distinct interaction patterns of MSACs with oxygenated species, elucidated through studying the p x - and p z -band centers and the resulting effects of orbital hybridization. Moreover, we successfully delineated the regulator role of carbon support species in enhancing the adsorption abilities of MSACs. By strategically pairing the appropriate main-group atoms with suitable carbon supports, we propose an innovative approach for the design of high-performance MSAC catalysts. [ABSTRACT FROM AUTHOR]

One order of magnitude activity enhancement of pristine FePc molecular catalyst through cooperating with nitrogen-doped carbon micro-flower is achieved. The axial coordination effect between Fe active center and nitrogen atoms in support can break the electronic distribution symmetry of FeN x moieties and induce the electron delocalization on Fe active center and the electron localization on N, respectively, which favor the adsorption behavior of *OH intermediate. [Display omitted] • One order of magnitude activity enhancement of pristine FePc through cooperating with nitrogen-doped carbon matrix is achieved. • Systematic characterizations confirm the axial coordination effect between the FePc molecule and the nitrogen atoms in carbon support. • The catalyst exhibits a remarkable half-wave potential of 0.9 V and a high kinetic current density of 74.04 mA cm−2 at 0.85 V. • Theoretical calculations show that the axial coordination effect between Fe active center and nitrogen atoms in support can break the electronic distribution symmetry of FeN x moieties and induce the electron delocalization on Fe active center and the electron localization on N, respectively. Fe-N-C catalysts have been recognized as the most satisfactory candidates alternatively to Pt-based catalysts for oxygen reduction reaction (ORR). However, fine-tailoring of their intrinsic ORR catalytic activity still remains a great challenge due to the inferior accessibility and intrinsic activity of FeN x moieties. Herein, one order of magnitude activity enhancement of pristine Fe-N-C through cooperating with nitrogen-doped carbon micro-flower is achieved. The axial coordination effect between Fe active center and nitrogen atoms in support can break the electronic distribution symmetry of FeN x moieties and induce the electron delocalization on Fe active center and the electron localization on N, respectively, which favor the adsorption behavior of *OH intermediate. As a result, the catalyst exhibits a remarkable half-wave potential of 0.9 V and a high kinetic current density of 74.04 mA cm−2 at 0.85 V. In addition, when utilized as a cathode catalyst of liquid Zn-air batteries (ZABs), it possesses excellent electrochemical performance, for example, a high open circuit voltage (OCV) and peak power density of 1.59 V and 170.09 mW cm−2, respectively. This work provides a new understanding into the activity enhancement mechanism of Fe-N-C catalysts, and inspires electronic delocalization of active sites for adjusting catalytic activity. [ABSTRACT FROM AUTHOR]

• Strain could lower the conversion barrier of LiPSs on MXene. • Strain accelerates the conversion of LiPSs by downshifting the d -band center of the Ti. • HADDF-STEM and finite element methods have validated the import of strain in w-MXene. • Experiments confirm that the strain could accelerate the conversion of LiPSs. Accelerating the conversion of lithium polysulfides (Li 2 S n , n = 2–8) is the key to high-performance lithium-sulfur (Li-S) batteries. Design of versatile strategies is still desperately needed for facilitating the kinetic process of LiPSs conversion. Herein, we report an intuitive method, strain regulation, for improving the electrocatalytic performances of MXene for LiPSs conversion. The imported strain triggers the distortion of TiC 3 O 3 octahedron configuration and the downshift of the d -band center, which facilitates the charge transfer and conversion of LiPSs on MXene. Under the guidance of the simulations, the strain-induced wrinkle flower-shaped MXene is adopted to verify the effect of strains on the conversion efficiency of sulfur. The experiments prove that the conversion rate of LiPSs and the long cycle stability of batteries were enhanced by the strained MXene. Our first-principle simulations and experiments demonstrate that the introduction of strain is viable and capable of providing a new paradigm for developing high-performance Li-S batteries. [ABSTRACT FROM AUTHOR]