Energy Barrier For Dissociation Research Articles

Ultrafine Ru nanoparticles on nitrogen-doped CNT arrays for HER: A CVD-based protocol achieving microstructure design and strong catalyst-support interaction

Strong metal-support interactions (SMSIs) play a pivotal role in enhancing the catalytic activity and stability of supported metal catalysts in heterogeneous thermal catalysis, but construction of effective SMSIs remains challenging in electrocatalysis. As a ubiquitous and versatile support for electrocatalysts, carbon materials are generally too inert to generate SMSIs with the loaded metal active sites. We hereby report a CVD-based method to prepare Ru nanoparticles on arrays of oxygen- and nitrogen-doped CNTs grown on the fibers of carbon paper (Ru/ONCNT@CP). The SMSIs were manifested by electronic structure tuning of Ru nanoparticles and their partial embedment in the carbon support. The SMSIs result in optimized Gibbs free energy of H*, lowered energy barrier of H2O dissociation, and enhanced catalyst robustness. Combined with the hierarchical microstructure, high surface area and hydrophilic/aerophobic nature, the Ru/ONCNT@CP electrode displays excellent HER catalytic activity in 1 M KOH, requiring overpotentials of only 73, 180, and 252 mV to achieve current densities of 100, 500, and 800 mA cm−2, respectively. Moreover, the Ru/ONCNT@CP electrode exhibits outstanding stability, with negligible current decay after 120 h HER operation at 100 mA cm−2. This work features an effective and scalable approach for preparation of metal-loaded-carbon electrocatalysts with engineered microstructure and SMSIs.

Asymmetric orbital hybridization in Zn-doped antiperovskite Cu1−xZnxNMn3 enables highly efficient electrocatalytic hydrogen production

Rational design of efficient and robust earth-abundant alkaline hydrogen evolution reaction (HER) catalysts is a key factor for developing energy conversion technologies. Currently, antiperovskite nitride CuNMn3 has garnered significant interest due to its remarkable properties such as negative/zero thermal expansion and magnetocaloric effects. However, when utilized as hydrogen evolution catalysts, it encounters large challenge resulting from excessively strong/weak interactions with adsorbed H on Mn/Cu active sites, which leads to low HER activity. In this study, we introduce an asymmetric orbital hybridization strategy in Zn-doped Cu1−xZnxNMn3 by leveraging the localization of Zn electronic states to reconfigure the electronic structures of Cu and Mn, thereby reducing the energy barrier for water dissociation and optimizing Cu and Mn active sites for hydrogen adsorption and H2 production. Electrochemical evaluations reveal that Cu0.85Zn0.15NMn3 with x = 0.15 demonstrates exceptional electrocatalytic activity in alkaline electrolytes. A low overpotential of 52 mV at 10 mA cm−2 and outstanding stability over a 150-h test period are achieved, surpassing commercial Pt/C. This research offers a novel strategy for enhancing HER performance by modulating asymmetric hybridization of electron orbitals between multiple metal atoms within a material structure.

Understanding the promotion effect of Pt in the reaction system of water gas shift reaction catalyzed by Pt/α-MoC from theoretical perspectives

Pt/α-MoC is an outstanding catalyst for the low-temperature water gas shift (WGS, CO + H2O → H2 + CO2) reaction, exhibiting elevated activity, stability, and selectivity. In this study, three significant active site models (α-MoC-111, Pt-111, and Pt1/α-MoC-111) in Pt/α-MoC catalyst were established to investigate the promotion effect of Pt on the WGS reaction catalyzed by Pt/α-MoC. The results indicate that a synergistic effect at the metal-carbide interface enhances chemical activity compared to pure Pt-111 and α-MoC-111. Firstly, the surface of Pt1/α-MoC-111 exhibits strong metal-support interaction between Pt single atom and α-MoC-111 surface. Compared to the α-MoC-111 surface, the introduction of Pt strengthens the Mo−Mo bond while weakening the Mo−C bond. Secondly, adding a Pt atom significantly increases adsorption strength for CO and H2O, while decreasing it for products (CO2), oxides (O atom), and by-products (C atom). The advantage of suppressing surface carbon deposition and oxidation is observed on the surface of Pt1/α-MoC-111. Furthermore, elementary reactions from the three mainstream reaction pathways of the WGS reaction are systematically calculated to evaluate catalytic performance among these three active sites. On the Pt1/α-MoC-111 surface, activation energy barriers for H2O dissociation and CO oxidation are reduced. This provides theoretical ideas for designing high-efficiency α-MoC based catalysts in the future.

Interface and morphology engineering of Ru-FeCoP hollow nanocages as alkaline electrocatalyst for overall water splitting

Interface and Morphology engineering strategies of electrocatalysts are of great importance to promote water splitting performance, although still facing many challenges. In this work, we present a facile method for preparing Ru-anchored hollow FeCoP nanocages electrocatalyst with ultrathin sheets. The hollow structure composed of ultrathin nanosheets and rich heterogeneous interfaces benefit the as-synthesized catalyst to exhibit small overpotentials of 310 mV and 94 mV at the current density of 10 mA·cm−2 for oxygen evolution reaction and hydrogen evolution reaction, respectively. When Ru-FeCoP nanocages were employed as the bifunctional catalyst for overall water splitting, the potential of 1.65 V was obtained to reach the current density of 10 mA·cm−2. The experimental results confirmed that the formation of hierarchical hollow structure facilitated the exposure of active sites and enhanced the electrocatalytic activity. Meanwhile, XPS and DFT data also reveal that the presence of heterogeneous interfaces changed the electronic structure, optimized the absorption of the intermediates, significantly reduced the energy barrier of water dissociation and promoted the release of H2. This work offers an effective route for rational design of low-loading noble metal-anchored metal phosphide with the hierarchical hollow structure and rich interfaces towards overall water splitting.

Atomic-level coupled RuO2/BaRuO3 heterostructure for efficient alkaline hydrogen evolution reaction

The slow water dissociation is the rate-determining step that slows down the reaction rate in alkaline hydrogen evolution reaction (HER). Optimizing the surface electronic structure of the catalyst to lower the energy barrier of water dissociation and regulating the binding strength of adsorption intermediates are crucial strategy for boosting the catalytic performance of HER. In this study, RuO2/BaRuO3 (RBRO) heterostructures with abundant oxygen vacancies and lattice distortion were in-situ constructed under a low temperature via the thermal decomposition of gel-precursor. The RBRO heterostructures obtained at 550 °C exhibited the highest HER activity in 1 M KOH, showing an ultra-low overpotential of 16 mV at 10 mA cm−2 and a Tafel slope of 33.37 mV dec−1. Additionally, the material demonstrated remarkable durability, with only 25 mV of degradation in overpotential after 200 h of stability testing at 10 mA cm−2. Density functional theory calculations revealed that the redistribution of charges at the heterojunction interface can optimize the binding energies of H* and OH* and effectively lower the energy barrier of water dissociation. This research offers novel perspectives on surpassing the water dissociation threshold of alkaline HER catalysts by means of a systematic design of heterogeneous interfaces.

A 2D Ba2N Electride for Transition Metal-Free N2 Dissociation under Mild Conditions.

N2 activation is a key step in the industrial synthesis of ammonia and other high-value-added N-containing chemicals, and typically is heavily reliant on transition metal (TM) sites as active centers to reduce the large activation energy barrier for N2 dissociation. In the present work, we report that a 2D electride of Ba2N with anionic electrons in the interlayer spacings works efficiently for TM-free N2 dissociation under mild conditions. The interlayer electrons significantly boost N2 dissociation with a very small activation energy of 35 kJ mol-1, as confirmed by the N2 isotopic exchange reaction. The reaction of anionic electrons with N2 molecules stabilizes (N2)2- anions, the so-called diazenide, in the large interlayer space (∼4.5 Å) sandwiched by 2 cationic slabs of Ba2N as the main intermediate.

Synergistic reaction kinetics of Pt single atoms/MoS2 and nanoparticles for energy-saving hydrogen production assisted by green electrosynthesis of azotetrazolate compound

Overall water splitting (OWS) involves two important half-reactions, namely hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). However, due to the high theoretical overpotential of OER, OWS needs to be realized with high energy consumption. Using anodic oxidation reaction with lower theoretical potential to replace oxygen evolution reaction (OER) can effectively reduce the energy consumption of overall water splitting (OWS) for hydrogen production. Here, we introduce a new oxidation reaction of green electrosynthesis of energetic materials (EMs) and coupled with OWS. The catalyst was prepared by electrodepositing Pt nanoparticles (Pt NPs) and Pt single atoms (Pt SAs) on MoS2 nanosheets, which drives highly-efficient hydrogen production of 35.6 mV to drive 10 mA cm−2. DFT calculations reveal the synergistic mechanism of Pt NPs and Pt SA/MoS2 substrate for promoting hydrogen production, is that the energy barrier of water dissociation was reduced on the Pt NC sites and the produced H* migrated to the adjacent S sites for Heyrovsky step, while the Pt SA sites served as electron regulator for more thermoneutral H* adsorption on S sites, realizing the synergistic reaction kinetics in MoS2/Pt for promoting alkaline HER. Importantly, by integrating the OWS and electrosynthesis of 5,5′-azotetrazole (ZT) EMs, the cell voltage can be significantly reduced to 1.29 V at 10 mA cm−2, realizing low-energy-consumption for hydrogen production. Meanwhile, the green electrosynthesis of ZT is achieved to avoid the hazardous process of traditional preparation methods. This study presents a new strategy for green electrosynthesis of EMs and low-energy-consumption hydrogen production.

Encapsulation of sulfur in MoS2-modified metal-organic framework-derived N, O-codoped carbon host for sodium–sulfur batteries

Room-temperature sodium–sulfur batteries (RT Na-S) are promising energy storage systems with high energy densities and low costs. Nevertheless, drawbacks, including the limited cycle life and sluggish redox kinetics of sodium polysulfides, hinder their implementation. Herein, a heterostructure of MoS2 nanosheets coated on a metal–organic framework (MOF)-derived N, O-codoped flower-like carbon matrix (NOC) was designed as a sulfur host for advanced RT Na-S batteries. The NOC@MoS2 hierarchical host provided a sufficient space to guarantee a high sulfur loading and confinement for the volume expansion of sulfur during the charge/discharge process. According to first-principle calculations, the NOC@MoS2 composite exhibited metallic conductivity because electronic states crossed the Fermi level, which indicates that the introduction of NOC significantly improved the electronic conductivity of MoS2. Furthermore, electron transfer from MoS2 to the O-doped carbon sites was observed owing to the strong electronegativity of O, which can effectively increase the Lewis acidity of MoS2 and weaken the sodium–sulfur bonds in sodium polysulfides after adsorption on the cathode, leading to reductions in the Na2S dissociation energy barrier and Gibbs free energy for the rate-limiting step of the sulfur reduction process. Therefore, with the synthetic effects of MoS2 and N, O-codoped carbon, the obtained cathode exhibited a superior electrochemical performance.

Theoretical investigation of adsorption and dissociation behaviors of H2O molecules on the surfaces of Transition-metal doped γ-graphyne

The characteristics of adsorption and dissociation of H2O molecules on the surfaces of γ-graphyne doped with transition metal atoms (TM-GY) were explored by the first-principles calculation. Transition metal single-atom could be confined firmly at the center of acetylene ring, and it is difficult to migrate to the adjacent center of benzene ring because of the very high diffusion energy barrier. The positions of doped atoms on the TM-GY surfaces could be used as active sites, and H2O molecules on the Sc/Ti/V/Cr/Mn/Fe-GY surfaces all are a typical chemical adsorption. All possible reaction pathways for H2O molecules dissociation on TM-GY surfaces were evaluated. Adsorbed H2O molecules on TM-GY surfaces are more likely to be dissociated into OH and H along the path1 with a lower reaction energy barrier (less than 1.248 eV). Especially, for V/Cr-GY surface, the dissociation energy barrier is as low as 0.317/0.312 eV, this process is exothermic along with a large amount of energy releasing of about 1.524/1.709 eV. Therefore, stable doped substrate together with the lower dissociation barrier promises that TM-GY may serve as a high efficiency catalyst for H2O dissociation.

Titanium-doped copper oxide/ruthenium heterostructure constructed on Cu3Ti nanosheet for efficient hydrogen evolution reaction in alkaline media

Platinum group metals (Pt, Ru, Ir, etc.) are the most active catalysts for acidic hydrogen evolution reaction (HER), yet they cannot deliver satisfactory performance in alkaline media owing to the high energy barrier of water dissociation. Here, we report the outstanding alkaline HER performance of Cu3Ti-supported Ti-doped CuO/Ru (Cu3Ti@CTO/Ru) heterostructure catalysts, which were fabricated simply by an impregnation-heat treatment method. Density functional theory calculation results indicate that the energy barriers of both water dissociation and hydrogen desorption at CTO/Ru heterointerface are significantly reduced relative to Ru catalyst alone. As a result, the Cu3Ti@CTO/Ru catalyst at the optimum Ru loading amount achieves a low overpotential of 34 mV at the current density of 10 mA cm−2 and an ultra-low Tafel slope of 29 mV dec-1 in 1 M KOH, outperforming the benchmark 20% Pt/C catalyst. This study provides new insight into the development of advanced alkaline HER catalysts.

Greatly Boosting Seawater Hydrogen Evolution by Surface Amorphization and Morphology Engineering on MoO2/Ni3(PO4)2

AbstractHydrogen production through seawater electrolysis faces several challenges, one of which involves the development of electrocatalysts with high catalytic performance. Here, surface amorphization and morphology engineering are combined to design a novel electrocatalyst for highly‐efficient hydrogen evolution reaction (HER). The surface‐amorphized MoO2/Ni3(PO4)2 microcolumns supported on nickel foam (SA‐MoO2/Ni3(PO4)2/NF) display remarkable performance with low overpotentials of 34 and 46 mV at a current density of 10 mA cm−2 in 1 m KOH and alkaline seawater, respectively. In addition, the alkaline electrolysis cell (AEC) integrated with SA‐MoO2/Ni3(PO4)2/NF as the cathode and Ni foam as the anode achieves a current density of 100 mA cm−2 at 1.87 V in 6 m KOH seawater at 60 °C, superior to that of industrial NiMo electrode as cathode (2.05 V). DFT calculations demonstrate that the surface amorphous layer (MoOx) improves the hydrogen adsorption energy of sample and reduces the energy barrier of water dissociation. It is found that substantial improvement in catalytic performance stems from the synergistic effect between surface amorphization and unique microcolumn morphology. These findings may provide insights into combining surface amorphization and morphology engineering strategies to enhance catalytic performance and pave the way for the development of highly efficient seawater HER electrocatalysts.

Turing structuring with multiple nanotwins to engineer efficient and stable catalysts for hydrogen evolution reaction

Low-dimensional nanocrystals with controllable defects or strain modifications are newly emerging active electrocatalysts for hydrogen-energy conversion and utilization; however, a crucial challenge remains in insufficient stability due to spontaneous structural degradation and strain relaxation. Here we report a Turing structuring strategy to activate and stabilize superthin metal nanosheets by incorporating high-density nanotwins. Turing configuration, realized by constrained orientation attachment of nanograins, yields intrinsically stable nanotwin network and straining effects, which synergistically reduce the energy barrier of water dissociation and optimize the hydrogen adsorption free energy for hydrogen evolution reaction. Turing PtNiNb nanocatalyst achieves 23.5 and 3.1 times increase in mass activity and stability index, respectively, compared against commercial 20% Pt/C. The Turing PtNiNb-based anion-exchange-membrane water electrolyser with a low Pt mass loading of 0.05 mg cm−2 demonstrates at least 500 h stability at 1000 mA cm−2, disclosing the stable catalysis. Besides, this new paradigm can be extended to Ir/Pd/Ag-based nanocatalysts, illustrating the universality of Turing-type catalysts.

An Amiable Design of Cobalt Single Atoms as the Active Sites for Oxygen Evolution Reaction in Desalinated Seawater.

Green fuel from water splitting is hardcore for future generations, and the limited source of fresh water (<1%) is a bottleneck. Seawater cannot be used directly as a feedstock in current electrolyzer techniques. Until now single atom catalystswerereported by many synthetic strategies using notorious chemicals and harsh conditions. A cobalt single-atom (CoSA) intruding cobalt oxide ultrasmall nanoparticle (Co3 O4 USNP)-intercalated porous carbon (PC) (CoSA-Co3 O4 @PC) electrocatalystwassynthesized from the waste orange peel as a single feedstock (solvent/template). The extended X-ray absorption fine structure spectroscopy (EXAFS) and theoretical fitting reveal a clear picture of the coordination environment of the CoSA sites (CoSA-Co3 O4 and CoSA-N4 in PC). To impede the direct seawater corrosion and chlorine evolution the seawater has been desalinated (Dseawater) with minimal cost and the obtained PC is used as an adsorbent in this process. CoSA-Co3 O4 @PC shows high oxygen evolution reaction (OER) activity in transitional metal impurity-free (TMIF) 1M KOH and alkaline Dseawater. CoSA-Co3 O4 @PC exhibits mass activity that is 15 times higher than the commercial RuO2 . Theoretical interpretations suggest that the optimized CoSA sites in Co3 O4 USNPs reduce the energy barrier for alkaline water dissociation and simultaneously trigger an excellent OER followed by an adsorbate evolution mechanism (AEM).

Competitive Adsorption Mechanism of Defect‐Induced d‐Orbital Single Electrons in SrRuO3 for Alkaline Hydrogen Evolution Reaction

AbstractIn the alkaline hydrogen evolution reaction (HER), the dissociation energy barrier of water, and the easy adsorption of OH on the catalyst are key factors that limit the catalytic activity. This work proposes a novel competing adsorption mechanism driven by dz2 electrons in the context of the alkaline HER. The high concentration of oxygen vacancies in Co doped SrRuO3 (V‐SRCO) results in the electron filling in the Ru 4dz2 orbital. Under alkaline conditions, the V‐SRCO exhibits a low overpotential of only 57.8 mV with a Tafel slope of 35 mV dec−1. Moreover, it exhibits sustained high activity for 60 h. The high HER activity of V‐SRCO can be attributed to the presence of a single electron in the dz2 orbital, which reduces the energy barrier for water dissociation. More importantly, the active electrons in the dz2 orbital can inject into the antibonding orbitals of OH, creating an unfavorable environment for OH adsorption on the catalyst. This work provides favorable conditions for efficient HER.

Mechanistic Insight into the Propane Oxidation Dehydrogenation by N2O over Cu-BEA Zeolite with Diverse Active Site Structures

The present work theoretically investigated propane oxidation dehydrogenation by utilizing N2O as an oxidant (N2O-ODHP) over Cu-BEA with three different types of active site, including monomeric Cu ([Cu]+), dimeric Cu ([Cu−Cu]2+), and distant monomeric Cu sites ([Cu]+—[Cu]+). Energetically, we calculated that the monomeric [Cu]+ is favorable for the αH dehydrogenation step (∆E = 0.05 eV), which, however, suffers from high barriers of N2O dissociation and βH dehydrogenation steps of 1.40 and 1.94 eV, respectively. Although the dimeric [Cu−Cu]2+ site with a Cu—Cu distance of 4.91 Å is much more favorable for N2O dissociation (0.95 eV), it still needs to overcome an extremely high barrier (∆E = 2.15 eV) for βH dehydrogenation. Interestingly, the distant [Cu]+—[Cu]+ site with the Cu—Cu distance of 5.82 Å exhibits low energy barriers for N2O dissociation (0.89 eV) and ODHP steps (0.01 and 0.33 eV) due to the synergistic effect of distant [Cu]+. The microkinetic analyses quantitatively verified the superior activity of the distant [Cu]+—[Cu]+ site with a reaction rate being eight to nine orders of magnitude higher than those of the monomeric and the dimeric Cu sites, and this is related to its ready charge-transfer ability, as shown by the partial Density of State (PDOS) analysis and the static charge differential density analysis in this study. Generally, the present work proposes that the distance between the [Cu]+ sites plays a significant and important role in N2O-ODHP over the Cu-based zeolite catalyst and modulates Cu—Cu distance, and this constitutes a promising strategy for highly-efficient Cu-zeolite catalyst design for N2O-ODHP.

Waste biomass-derived N, P co-doping carbon aerogel-coated CoxFe1−xP with modulated electron density for efficient electrooxidation of contaminants

Developing low-cost, green, high-performing electrode materials to address environmental pollutants and the energy crisis is significant but challenging. Herein, the bimetallic iron cobalt phosphide coated in waste biomass-derived N, P co-doping carbon (CoxFe1−xP@NPC) is constructed. Furthermore, the active site density and the water decomposition energy barrier of surface-coated NPC are modulated by optimizing the electronic structure of CoxFe1−xP via doping engineering. The Fe-modulated CoxFe1−xP@NPC exhibits a hierarchical porous self-supporting structure and excellent physical & chemical properties with excellent electrooxidation performance, achieving over 95% removal of TCH within 60 min. The density functional theory (DFT) calculations further confirms that N carries more positive charge and P carries more negative charge in the NPC of CoxFe1−xP@NPC with Fe modulation, which can promote the adsorption and dissociation of water molecules. Of note, Co0.75Fe025P@NPC displays a low water dissociation energy barrier to produce ·OH and a high energy barrier to produce O2 than its counterparts. This study offers new insight into controllable modulation of biomass carbon-based composite electrode catalytic activity for high-efficiency degradation of contaminants.

Cyclodextrin-supported Co(OH)2 Clusters as Electrocatalysts for Efficient and Selective H2 O2 Synthesis.

Co-based material catalysts have shown attractive application prospects in the 2 e- oxygen reduction reaction (ORR). However, for the industrial synthesis of H2 O2 , there is still lack of Co-based catalysts with high production yield rate. Here, novel cyclodextrin-supported Co(OH)2 cluster catalysts were prepared via a mild and facile method. The catalyst exhibited remarkable H2 O2 selectivity (94.2 % ~ 98.2 %), good stability (99 % activity retention after 35 h), and ultra-high H2 O2 production yield rate (5.58 mol gcatalyst -1 h-1 in the H-type electrolytic cell), demonstrating its promising industrial application potential. Density functional theory (DFT) reveals that the cyclodextrin-mediated Co(OH)2 electronic structure optimizes the adsorption of OOH* intermediates and significantly enhances the activation energy barrier for dissociation, leading to the high reactivity and selectivity for the 2 e- ORR. This work offers a valuable and practical strategy to design Co-based electrocatalysts for H2 O2 production.

Cyclodextrin‐supported Co(OH)2 Clusters as Electrocatalysts for Efficient and Selective H2O2 Synthesis

AbstractCo‐based material catalysts have shown attractive application prospects in the 2 e− oxygen reduction reaction (ORR). However, for the industrial synthesis of H2O2, there is still lack of Co‐based catalysts with high production yield rate. Here, novel cyclodextrin‐supported Co(OH)2 cluster catalysts were prepared via a mild and facile method. The catalyst exhibited remarkable H2O2 selectivity (94.2 % ~ 98.2 %), good stability (99 % activity retention after 35 h), and ultra‐high H2O2 production yield rate (5.58 mol gcatalyst−1 h−1 in the H‐type electrolytic cell), demonstrating its promising industrial application potential. Density functional theory (DFT) reveals that the cyclodextrin‐mediated Co(OH)2 electronic structure optimizes the adsorption of OOH* intermediates and significantly enhances the activation energy barrier for dissociation, leading to the high reactivity and selectivity for the 2 e− ORR. This work offers a valuable and practical strategy to design Co‐based electrocatalysts for H2O2 production.

Ab initio molecular dynamics study of H2 dissociation mechanisms on Cu13 and defective graphene-supported Cu13 clusters: active sites, energy barriers and adsorption states.

Ab initio molecular dynamics calculations were performed to study H2 dissociation mechanisms on Cu13 and defective graphene-supported Cu13 clusters. The study reveals that seven types of corresponding dissociation processes are found on the two clusters. The average dissociation energy barriers are 0.51 eV on the Cu13 cluster and 0.12 eV on the defective graphene-supported Cu13 cluster, which are lowered by ~ 19% and ~ 81% compared with the pristine Cu(111) surface, respectively. Furthermore, compared with the pure Cu13 cluster, the average dissociation energy barrier on the defective graphene-supported Cu13 cluster is substantially reduced by about 76%. The preferred dissociation mechanisms on the two clusters are H2 located at a top-bridge site with the barrier heights of 0.30 eV on the Cu13 cluster and - 0.31 eV on the defective graphene-supported Cu13 cluster. Analysis of the H-Cu bond interactions in the transition states shows that the antibonding-orbital center shifts upwards on the defective graphene-supported Cu13 cluster compared with the one on the Cu13 cluster, which explains the reduction of the dissociation energy barrier. The average adsorption energy of dissociated H atoms is also greatly enhanced on the defective graphene-supported Cu13 cluster, about twice that on pure Cu13.

Ultrafine PtMo Nanocrystals Confined on N‐Doped Carbon Toward Efficient pH‐Universal Hydrogen Evolution Reaction

AbstractPt‐based nanocrystals with tunable electronic structure and optimized atom efficiency are essential for boosting the hydrogen evolution reaction (HER) performance and further industrial application. However, the synthesis of uniform and ordered nanocrystals is still a challenge due to the uncontrollable size growth of metal particles, restricting the active sites toward the desired catalytic activity. Herein, the synthesis of ultrafine bimetal PtMo nanocrystals on N‐doped carbon (PtMo‐NC) through an anchoring‐sites engineering strategy is reported, in which the N‐rich carbon can provide abundant sites to anchor the metal atoms and suppress the over aggregation. The PtMo‐NC catalyst exhibits superior HER performance in both alkaline and acidic conditions, delivering a smaller overpotential (80 mV and 63 mV) at a current density of 100 mA cm−2 in alkaline and acidic media. Theoretical calculations reveal that the introduction of Mo atom into Pt can reduce the energy barrier of water molecule dissociation and optimize the H intermediate absorption strength on Pt sites, thus boosting the catalytic HER performance. This study offers a universal strategy to design ultrafine nanocatalysts to achieve high‐efficiency electrocatalysis.