Surface Science最新文献_第3页

Facile synthesis of pulsed laser deposited polymorphic WS2 nanolayers and manipulation of layer thickness by tuning laser energy 脉冲激光沉积多晶WS2纳米层的简易合成及激光能量调节对层厚的影响

IF 1.8 4区化学 Q3 CHEMISTRY, PHYSICAL

Surface Science

Pub Date : 2025-11-28 DOI: 10.1016/j.susc.2025.122893

Bidyut Bhattacharjee , Ashwini Kumar Sharma , Gobinda Pradhan

The WS₂ thin layers were deposited on SiO₂ /Si substrate by pulsed laser deposition (PLD). The third harmonic Q switched Nd:YAG (Neodymium-doped Yttrium Aluminum Garnet) laser of 355 nm wavelength and nanosecond pulse duration was used. The laser energy was tuned between 20 mJ to 30 mJ. The influence of the laser energy on the thickness, optical and electrical transport properties of the layers was studied. The A_1g (Γ) & E¹_2g(Γ) Raman peak position difference increased and the I E¹_2g/I A_1g peak intensity ratio decreased with the increase of the laser energy. It indicated the increase in the number of WS₂ layers with the increase of the laser energy. The X-ray diffraction (XRD) showed a mixed polymorphic phase of 2H and 1T WS₂. It also indicated prominent (002) 2H WS₂ peak for 25 mJ and 30 mJ laser energy and an additional 1T WS₂ peak for 20 mJ laser energy. The energy-dispersive X-ray (EDX) analysis showed S (Sulfur) deficient WS₂ layers. The spectroscopic ellipsometry (SE) was used to determine layer thickness, bandgap, electrical conductivity and carrier mobility of the layers. The SE fitted results showed WS₂ layer thickness of 0.7 nm, 1.4 nm & 2.0 nm for laser energy of 20 mJ, 25 mJ & 30 mJ, respectively. The SE fitted data showed that the conductivity and the bandgap decreased with the increase of the laser energy. The uniqueness of the study lies on low laser energy investigation of PLD and optical and electrical characterization of WS₂ layers by SE.

采用脉冲激光沉积（PLD）技术在SiO2 /Si衬底上制备了WS2薄层。采用三次谐波调Q Nd:YAG（掺钕钇铝石榴石）激光器，波长为355nm，脉冲时间为纳秒。激光能量在20mj到30mj之间调谐。研究了激光能量对膜层厚度、光输运和电输运性质的影响。随着激光能量的增加，A1g （Γ） & E12g（Γ）拉曼峰位置差增大，ie12g / ia1g峰强度比减小。结果表明，随着激光能量的增加，WS2层数增加。x射线衍射（XRD）结果显示为2H和1T WS2混合多晶相。在25 mJ和30 mJ激光能量下，有一个突出的（002）2H WS2峰，在20 mJ激光能量下有一个额外的1T WS2峰。能量色散x射线（EDX）分析显示WS2层缺乏S（硫）。利用椭圆偏振光谱（SE）测定了层的厚度、带隙、电导率和载流子迁移率。SE拟合结果显示，当激光能量为20 mJ、25 mJ和30 mJ时，WS2层厚度分别为0.7 nm、1.4 nm和2.0 nm。SE拟合数据表明，电导率和带隙随激光能量的增加而减小。本研究的独特之处在于PLD的低激光能量研究和WS2层的光电特性。

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引用次数: 0

Quantum-engineered metal-doped and vacancy-modified GaS Monolayers for efficient SO₂ gas sensing: insights from adsorption, electronic structure, and recovery dynamics 用于高效二氧化硫气体传感的量子工程金属掺杂和空位修饰气体单层：从吸附，电子结构和恢复动力学的见解

IF 1.8 4区化学 Q3 CHEMISTRY, PHYSICAL

Surface Science

Pub Date : 2025-11-26 DOI: 10.1016/j.susc.2025.122894

Majid Poormohamadi, Hossein Roohi

Efficient detection and removal of sulfur dioxide (SO₂) from the atmosphere are critical for environmental protection and public health. In this work, we employ quantum engineering approaches to explore the potential of metal-doped and vacancy-modified gallium sulfide monolayers (GaSMLs) as reusable and sensitive SO₂ gas sensors. Using Grimme DFT-D approach, we systematically investigate the adsorption energies, charge transfer characteristics, electronic structure changes, work function modifications, and recovery times for SO₂ adsorption on pristine, vacancy-defective, and various metal-doped GaSML configurations. The adsorption energies calculated for GaSMLs (pristine and defective) range from −9.27 to −49.0 kcal/mol for sulfur-site modifications and from −3.0 to −9.59 kcal/mol for gallium-site modifications, demonstrating a wide range of adsorption capabilities that can be systematically modulated through defect engineering. Our results reveal that metal doping at sulfur sites, particularly with Mn, Cr, and Ni, significantly enhances SO₂ adsorption strength, charge transfer, and work function, accompanied by a notable narrowing of the band gap. These doped systems exhibit a balanced recovery time ranging from hundreds to thousands of seconds, suggesting practical reusability with mild external stimuli. Vacancy defects at sulfur sites also offer promising sensor performance with rapid desorption kinetics. Conversely, Fe doping, despite exhibiting the strongest adsorption, results in prohibitively long recovery times, limiting sensor applicability. This integrated analysis identifies Mn, Cr, and Ni-doped GaSMLs as optimal candidates for high-performance, reusable SO₂ sensors, capable of efficient environmental SO₂ clearance. These findings provide valuable insights for the rational design of two-dimensional materials engineered at the quantum level for sustainable gas sensing and pollution control.

有效检测和去除大气中的二氧化硫（SO2）对环境保护和公众健康至关重要。在这项工作中，我们采用量子工程方法来探索金属掺杂和空缺修饰的硫化镓单层（GaSMLs）作为可重复使用和敏感的二氧化硫气体传感器的潜力。利用grime DFT-D方法，我们系统地研究了原始、空位缺陷和各种掺杂金属的GaSML构型对so2吸附的吸附能、电荷转移特性、电子结构变化、功函数修改和恢复时间。计算出的GaSMLs（原始和缺陷）的吸附能范围从- 9.27到- 49.0 kcal/mol的硫位点修饰和- 3.0到- 9.59 kcal/mol的镓位点修饰，表明了广泛的吸附能力，可以通过缺陷工程系统地调节。我们的研究结果表明，在硫位点上掺杂金属，特别是Mn、Cr和Ni，显著提高了so2的吸附强度、电荷转移和功函数，同时显著缩小了带隙。这些掺杂系统表现出数百到数千秒的平衡恢复时间，表明在轻微的外部刺激下实际可重复使用。硫位点的空位缺陷也提供了具有快速解吸动力学的有前途的传感器性能。相反，Fe掺杂尽管表现出最强的吸附，但导致恢复时间过长，限制了传感器的适用性。该综合分析确定Mn， Cr和ni掺杂的gasml是高性能，可重复使用的SO₂传感器的最佳候选材料，能够有效地清除环境中的SO₂。这些发现为在量子水平上合理设计用于可持续气体传感和污染控制的二维材料提供了有价值的见解。

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引用次数: 0

First-principles study of dehydrogenation on group IV elements Si, Ge, or Sn doped MgH2(110) surface IV族元素Si， Ge， Sn掺杂MgH2（110）表面脱氢的第一性原理研究

IF 1.8 4区化学 Q3 CHEMISTRY, PHYSICAL

Surface Science

Pub Date : 2025-11-26 DOI: 10.1016/j.susc.2025.122896

Yuhan Wang, Xingzhou Zhang, Zhiyuheng Li, Yan Li, Nanyu Cheng, Yijing Huang, Yongxin Wang

The dehydrogenation on group IV elements Si, Ge, or Sn doped MgH₂(110) surface was investigated by first-principles calculations. In addition, the dopant site preference was determined by comparing the total energies of different doping site systems. The results showed that Si and Ge prefer to occupy interstitial sites, while Sn prefers to replace one Mg atom. The electronic structure and density of states show that the doping of Si, Ge, or Sn significantly weakens the Mg-H bond on the surface of MgH₂(110), and the band gap of the system is reduced, leading to structural instability. Finally, the calculated results of dehydrogenation energy and activation energy barrier indicated that Ge best improves the thermodynamics and hydrogen desorption kinetics of the MgH₂(110) surface, followed by Si and Sn.

采用第一性原理计算方法研究了IV族元素Si、Ge、Sn掺杂MgH2（110）表面的脱氢现象。此外，通过比较不同掺杂位点体系的总能量，确定了掺杂位点的偏好。结果表明，Si和Ge倾向于占据间隙位，而Sn倾向于取代一个Mg原子。电子结构和态密度表明，Si、Ge或Sn的掺杂显著削弱了MgH2表面的Mg-H键（110），使体系带隙减小，导致结构不稳定。最后，脱氢能和活化能势垒的计算结果表明，Ge对MgH2（110）表面热力学和氢脱附动力学的改善效果最好，其次是Si和Sn。

引用次数: 0

First-principles calculations of Ti doping-induced charge transfer between NOx and MoS2 to enhance gas-sensitive sensing performance Ti掺杂诱导NOx和MoS2之间电荷转移以提高气敏传感性能的第一性原理计算

IF 1.8 4区化学 Q3 CHEMISTRY, PHYSICAL

Surface Science

Pub Date : 2025-11-25 DOI: 10.1016/j.susc.2025.122895

Tong Liu , Enqiang Hao , Xujie Wang , Congcong Zhu , Kaiyue Wang

The low-concentration adsorption of nitrogen oxide (NO_x) gases on traditional gas-sensitive materials poses significant challenges for the development of gas sensor devices. Two-dimensional materials, represented by transition metal sulfides, are regarded as one of the most promising candidates for next-generation gas-sensitive materials. In this study, we constructed a two-dimensional MoS₂ monolayer structure with strong hybridization capability via d-orbital transition metal Ti substitution doping (Ti–MoS₂). By modulating the electronic structure and bonding coordination between Ti and the MoS₂ matrix, we aimed to achieve highly efficient adsorption of NO_x. Based on density functional theory (DFT) calculations, we systematically compared and analyzed the energy band structures, charge density distributions, adsorption properties, and sensitivity of four gas molecules (NO₂, NO, CO, and CO₂) within the MoS₂ adsorption system before and after Ti doping. The results demonstrate that strong interactions and favorable charge transfer occur between the gas molecules and the substrate upon Ti doping, leading to significantly enhanced adsorption performance for all four gas molecules on the Ti–MoS₂ monolayer. In particular, the adsorption energies for NO₂ and NO increased by 2 to 4 times. Furthermore, using orbital hybridization theory and bonding theory, we deeply analyzed the influence of Ti doping on the energy bands and orbital hybridization, elucidating the interaction mechanism between Ti–MoS₂ and nitrogen oxides. This work provides a feasible strategy for enhancing the NO_x capture performance of two-dimensional molybdenum-based material systems.

传统气敏材料对氮氧化物（NOx）气体的低浓度吸附对气体传感器器件的发展提出了重大挑战。以过渡金属硫化物为代表的二维材料被认为是下一代气敏材料最有前途的候选者之一。在本研究中，我们通过d轨道过渡金属Ti取代掺杂（Ti - MoS2）构建了具有强杂化能力的二维MoS2单层结构。通过调节钛与MoS2基体之间的电子结构和键配，我们旨在实现对NOx的高效吸附。基于密度泛函理论（DFT）计算，系统比较和分析了Ti掺杂前后MoS2吸附体系中4种气体分子（NO2、NO、CO和CO2）的能带结构、电荷密度分布、吸附性能和灵敏度。结果表明，Ti掺杂后，气体分子与衬底之间发生了强烈的相互作用和有利的电荷转移，导致四种气体分子在Ti - mos2单层上的吸附性能显著增强。特别是对NO2和NO的吸附能提高了2 ~ 4倍。利用轨道杂化理论和成键理论，深入分析了Ti掺杂对能带和轨道杂化的影响，阐明了Ti - mos2与氮氧化物的相互作用机理。本研究为提高二维钼基材料体系的氮氧化物捕获性能提供了一种可行的策略。

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引用次数: 0

Operando hysteresis of a palladium surface during high-frequency gas-pulsing of ethylene into oxygen 乙烯进入氧气的高频气体脉冲过程中钯表面的操作迟滞

IF 1.8 4区化学 Q3 CHEMISTRY, PHYSICAL

Surface Science

Pub Date : 2025-11-24 DOI: 10.1016/j.susc.2025.122892

Ulrike Küst , Calley Eads , Julia Prumbs , Weijia Wang , Robert Temperton , Alexander Klyushin , Andrey Shavorskiy , Jan Knudsen

Catalytic active phases are often separated from inactive ones by their appearance/removal in heating/cooling experiments. Such experiments can reveal ignition, extinction, and often an associated hysteresis. The corresponding behavior and hysteresis under rapid gas composition changes in the milliseconds regime remain largely unexplored. However, such experiments can potentially be highly rewarding as catalytic properties of surfaces that have not yet equilibrated to the gas phase can be studied. Here, we use time-resolved Ambient Pressure X-ray Photoelectron Spectroscopy (tr-APXPS) to study ethylene oxidation on polycrystalline Pd during modulation of the C₂H₄:O₂ ratio. By combining 10 Hz gas pulsing with 25 kHz spectral acquisition, we track both gas phase and surface chemistry under non-equilibrium conditions and reveal and discuss a pronounced hysteresis.

在加热/冷却实验中，催化活性相通常通过其出现/去除来与非活性相分离。这样的实验可以揭示点火、熄灭以及通常相关的滞后现象。在毫秒级的气体成分快速变化下，相应的行为和滞后在很大程度上仍未被探索。然而，这样的实验可能是非常有益的，因为还没有平衡到气相的表面的催化性能可以被研究。在这里，我们使用时间分辨环境压力x射线光电子能谱（tr-APXPS）研究了C2H4:O2比调制过程中乙烯在多晶Pd上的氧化。通过将10hz气体脉冲与25khz光谱采集相结合，我们在非平衡条件下跟踪气相和表面化学，并揭示和讨论了明显的滞后。

引用次数: 0

The sensing mechanism of metal (Ag, Au, Pd, Pt)-doped WSe2 monolayer for dissolved gases in transformer oil: A first-principle study 金属（Ag, Au, Pd, Pt）掺杂WSe2单层对变压器油中溶解气体的传感机理：第一性原理研究

IF 1.8 4区化学 Q3 CHEMISTRY, PHYSICAL

Surface Science

Pub Date : 2025-11-14 DOI: 10.1016/j.susc.2025.122891

Qing An , Junhua Wang , Ying He , Jianing Zhou , Xiaolan Yang

In the works, the effect of noble metal atoms (Ag, Au, Pd, Pt) as dopants on the behaviour of WSe₂ monolayer for adsorption of four key dissolved gases (C₂H₂, CH₄, CO, H₂) in transformer oil has been studied in depth using density-functional theory (DFT). It is shown that WSe₂ exhibits weak adsorption energies for C₂H₂, CH₄, CO, and H₂ molecules (below -0.02 eV). Calculations revealed that Ag, Au, Pd, and Pt doping significantly enhanced the interactions between gas molecules and the WSe₂ surface. Notably, the adsorption energy for C₂H₂ increased to -1.0 eV, with other molecules also showing marked increases, the adsorption capacity of Ag, Au, Pd, Pt- WSe₂ nanosheets for dissolved gases in transformer oils is in the order of C₂H₂ > CH₄ > H₂> CO, Ag, Au, Pd, and Pt atoms enhance the chemical adsorption capacity of WSe₂ by acting as electron donors and undergoing charge transfer with gas molecules. By calculating recovery times, it is predicted that Ag, Au, Pd, and Pt doped WSe₂ monolayers can detect C₂H₂ gas at 398 K after brief heating (8.17 s, 1.64 s, 6.28 s, and 2.47 s, respectively). This study provides a theoretical reference of significant value for WSe₂ sensors in monitoring dissolved gases generated by internal faults in transformer oil.

本文利用密度泛函理论（DFT）深入研究了贵金属原子（Ag、Au、Pd、Pt）作为掺杂剂对WSe2单层膜吸附变压器油中4种关键溶解气体（C2H2、CH4、CO、H2）行为的影响。结果表明，WSe₂对c2h₂、CH₄、CO和H₂分子（-0.02 eV以下）具有较弱的吸附能。计算表明，Ag、Au、Pd和Pt的掺杂显著增强了气体分子与WSe₂表面的相互作用。Ag、Au、Pd、Pt- WSe₂纳米片对变压器油中溶解气体的吸附能力依次为C2H2 >； CH4 > H2>； CO、Ag、Au、Pd、Pt原子作为电子给体与气体分子发生电荷转移，增强了WSe₂的化学吸附能力。通过计算恢复时间，预测Ag、Au、Pd和Pt掺杂的WSe₂单层在398 K加热后（分别为8.17 s、1.64 s、6.28 s和2.47 s）可以检测到c2h₂气体。本研究为WSe2传感器监测变压器油内部故障产生的溶解气体提供了有重要价值的理论参考。

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引用次数: 0

Surface chemistry of monochloramine catalyzed by Fe(111) 铁（111）催化单氯胺的表面化学

IF 1.8 4区化学 Q3 CHEMISTRY, PHYSICAL

Surface Science

Pub Date : 2025-11-12 DOI: 10.1016/j.susc.2025.122890

Oloruntoba S. Agbelusi , Subash Pandey , Sonam , Neetu Goel , R.M. D. Naveen Tharaka , Journey A. Lopez , Kathryn A. Perrine

Monochloramine (NH₂Cl) is a secondary disinfectant used for water purification and interacts with iron materials in various environments. Iron surfaces undergo reduction-oxidation and corrosion, where zero-valent iron sites are produced at complex interfaces. The initial stages of the reaction of monochloramine (NH₂Cl) have been studied on Fe(111), as a model for iron pipelines and mineral surfaces, at the gas/solid interface in ultra-high vacuum conditions. Using in situ infrared reflection absorption spectroscopy, NH₂Cl was found to adsorb molecularly at -160 °C, by observation of amine vibrational signatures. Auger electron spectroscopy was used to detect the presence of chloride to amine in a 3:1 ratio. Upon annealing, the NH₂Cl multilayer was found to desorb from Fe(111) at -120 °C, and the monolayer also undergoes molecular dissociation. At 34 °C, NH₂Cl primarily binds through the chloride species, thus blocking sites for NH₂ adsorption. Density functional theory computations and X-ray photoelectron spectroscopy confirmed two favorable chemisorbed orientations, both through binding of chloride. Further annealing allowed for chloride desorption before 400 °C, suggesting decomposition. The NH₂Cl is found to undergo a dechlorination mechanism, similar to chlorohydrocarbon reactions on iron surfaces. These findings reveal the mechanism of the chloramine disinfectant on metallic iron interfaces and its role in pipelines and water systems.

一氯胺（NH2Cl）是一种用于水净化的二级消毒剂，在各种环境中与铁物质相互作用。铁表面经过还原氧化和腐蚀，在复杂的界面上产生零价铁位点。以铁管道和矿物表面为模型，研究了超高真空条件下单氯胺（NH2Cl）在Fe（111）气固界面上反应的初始阶段。利用原位红外反射吸收光谱，通过观察胺的振动特征，发现NH2Cl在-160°C时具有分子吸附。用俄歇电子能谱法以3:1的比例检测氯与胺的存在。退火后，发现多层NH2Cl在-120℃时与Fe（111）脱附，单层NH2Cl也发生分子解离。在34℃时，NH2Cl主要通过氯化物结合，从而阻断了NH2吸附的位点。密度泛函理论计算和x射线光电子能谱证实了两个有利的化学吸收取向，都是通过氯化物的结合。在400°C之前进一步退火使氯化物解吸，表明分解。发现NH2Cl经历脱氯机制，类似于铁表面上的氯烃反应。这些发现揭示了氯胺消毒剂对金属铁界面的作用机理及其在管道和水系统中的作用。

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引用次数: 0

Spatial evolution of the electronic states near a defect in 1T-TaS₂ 1t - ta2缺陷附近电子态的空间演化

IF 1.8 4区化学 Q3 CHEMISTRY, PHYSICAL

Surface Science

Pub Date : 2025-11-11 DOI: 10.1016/j.susc.2025.122888

Yuto Nakashima , Sora Kobayashi , Atsushi Nomura , Hideaki Sakata

The Mott collapse is of significant interest, as it can lead to exotic behaviors such as high-temperature superconductivity, making its underlying mechanisms crucial to understand. The Mott state is realized in 1T-TaS₂, a member of transition metal dichalcogenides, due to in-plane interactions among Ta d-electrons. In this study, we investigated how the Mott state collapsed near an atomic defect in 1T-TaS₂ scanning tunneling microscopy (STM)/scanning tunneling spectroscopy (STS) measurements at 4.2 K. As the STM tip approached the atomic defect, we observed an overall shift of the dI/dV spectra towards positive bias, accompanied by the emergence of spatially localized in-gap states above the Fermi energy. In closer proximity to the defect, the gap structure at the Fermi energy transformed into a single-peak feature. This sequence of spatial evolution in the electronic structure can be interpreted as the Mott collapse in response to the amount of hole doping.

莫特坍缩引起了人们的极大兴趣，因为它可能导致诸如高温超导等奇异行为，因此了解其潜在机制至关重要。由于Ta d电子之间的平面相互作用，在过渡金属二硫族元素1T-TaS 2中实现了Mott态。在这项研究中，我们研究了在4.2 K的1T-TaS 2扫描隧道显微镜(STM)/扫描隧道光谱（STS）测量中，Mott态是如何在原子缺陷附近崩溃的。当STM尖端接近原子缺陷时，我们观察到dI/dV光谱总体上向正偏置偏移，伴随着费米能量以上的空间局域隙态的出现。在更接近缺陷处，费米能量处的间隙结构转变为单峰特征。这种电子结构的空间演化序列可以解释为随空穴掺杂量的变化而发生的Mott塌缩。

引用次数: 0

Hydrogen interlayer adsorption on Ti-functionalized Mg(0001). A density functional theory research 氢在ti功能化Mg（0001）上的层间吸附。密度泛函理论研究

IF 1.8 4区化学 Q3 CHEMISTRY, PHYSICAL

Surface Science

Pub Date : 2025-11-10 DOI: 10.1016/j.susc.2025.122889

Víctor A. Ranea

Hydrogen storage is one of the growing topics in recent years. In the present manuscript, hydrogen adsorption on the pristine and titanium-functionalized Mg(0001) surface is studied applying density functional theory. Ti adsorption between the external layers is more stable than on the surface. Increasing slightly the Titanium coverage, increases the binding energy per Ti atom. Molecular hydrogen interaction with the clean Mg surface is weak (adsorption energy of

\approx

-0.03 eV/H

_{2}

) whereas dissociative adsorption is not stable. However, hydrogen dissociative adsorption between the external layers near adsorbed Titanium atoms, is stable. This indicates the adsorbed Ti atoms enhance the hydrogen storage of the Mg surface. Hydrogen adsorption is less stable as its coverage increases (in the hydrogen low coverage regime). Charge density analysis and activation energy calculations are performed. Titanium-functionalized Mg(0001) surface seems to be a promising material in the topic hydrogen storage.

储氢是近年来日益热门的话题之一。在本手稿中，氢吸附在原始和钛功能化的Mg（0001）表面应用密度泛函理论进行了研究。钛在外层之间的吸附比表面吸附更稳定。稍微增加钛的覆盖率，增加每个钛原子的结合能。分子氢与清洁Mg表面的相互作用较弱（吸附能≈-0.03 eV/H2），而解离吸附不稳定。然而，氢解离吸附在外层附近的钛原子之间，是稳定的。这表明吸附的Ti原子增强了Mg表面的储氢能力。氢的吸附随着其覆盖范围的增加而不稳定（在氢低覆盖范围内）。进行了电荷密度分析和活化能计算。钛功能化的Mg（0001）表面似乎是一种很有前途的储氢材料。

引用次数: 0

Theoretical study of hydrogen activation and reduction of an oxidized maghemite surface, γ-Fe₂O₃, (001) by monovacancy formation: An analysis using density functional theory (DFT) 氧化磁赤铁矿表面γ-Fe₂O₃（001）单空位形成氢活化还原的理论研究：密度泛函理论（DFT）分析

IF 1.8 4区化学 Q3 CHEMISTRY, PHYSICAL

Surface Science

Pub Date : 2025-11-08 DOI: 10.1016/j.susc.2025.122877

Yenner Bentarcurt , Mónica Calatayud , Javier Fernández-Sanz , Jaime Klapp , Fernando Ruette

The theoretical investigation of the H₂ interaction with the stable (001) oxidized maghemite surface revealed the feasibility of physisorption on different O-top and Fe-O bridge sites. Water and O vacancy formations at O-center sites occurred in a single step with energy barriers ranging from 1.65 to 2.20 eV. Two reaction steps were identified for the formation of O vacancies (Ov) on heterolytic two-center sites. In the first step, the H₂ dissociation occurs through an intermediate with OH and Fe-H bonds on the surface, the energy barriers being the range of 0.45–0.87 eV. In the second step, Fe-bonded hydrogen migrates to the nearby O atom, with energy barriers of 0.25–0.65 eV. The formation of an Ov results in a reduction of the surface accompanied by an increase in the d-electron states close to the Fermi level, as indicated by the rise of Fe electronic density. A second H₂ molecule heterolytically dissociated on the reduced surface exhibited similar dissociation energies but higher stability than that on the oxidized surface. The PDOS of the 1s orbitals of H atoms adsorbed on the reduced surface showed that those bonded to Fe atoms were close to the Fermi level, indicating high reactivity toward hydrogenation.

H2与稳定的（001）氧化磁铁矿表面相互作用的理论研究揭示了在不同的o顶和Fe-O桥位上物理吸附的可行性。在O中心位置形成水和O空位是一步完成的，能垒范围在1.65 ~ 2.20 eV之间。确定了在异裂双中心位点上形成O空位（Ov）的两个反应步骤。在第一步中，H2通过具有OH和Fe-H键的中间体进行解离，能垒范围为0.45-0.87 eV。第二步，铁键氢迁移到附近的O原子，能垒在0.25-0.65 eV之间。Ov的形成导致表面的减小，并伴随着接近费米能级的d电子态的增加，如铁电子密度的增加所示。另一个H2分子在还原表面上异解离，表现出与氧化表面相似的解离能，但稳定性更高。还原表面吸附氢原子1s轨道的PDOS表明，与铁原子键合的氢原子的PDOS接近费米能级，对加氢反应具有较高的活性。

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引用次数: 0