Structure Of Metal Atoms Research Articles

Understanding electron structure of covalent triazine framework embraced with gold nanoparticles for nitrogen reduction to ammonia

Regulating the electron structure and precise loading sites of metal-active sites within the highly conjugated and porous covalent-triazine frameworks (CTFs) is essential to promoting the nitrogen reduction reaction (NRR) performance for electrocatalytic ammonia (NH3) synthesis under ambient conditions. Herein, experimental method and density functional theory (DFT) calculations were conducted to deeply probe the effect on NRR of the modulation of modulating the electron structure and the loading site of gold nanoparticles (Au NPs) in a two-dimensional (2D) CTF. 2D CTF synthesized using melem and hexaketocyclohexane octahydrate as building blocks (denoted as M−HCO−CTF) served as a robust scaffold for loading Au NPs to form an M−HCO−CTF@AuNP hybrid. DFT results uncovered that well-defined Au sites with tunable local structure were the active site for driving the NRR, which can significantly suppress the conversion of H+ into *H adsorption and enhance the nitrogen (N2) adsorption/activation. The overlapped Au (3d) and *N2 (2p) orbitals lowered the free energy of the rate-determining step to form *NNH, thereby accelerating the NRR. The M−HCO−CTF@AuNPs electrocatalyst exhibited a large NH3 yield rate of 66.3 μg h−1 mg−1cat. and a high Faraday efficiency of 31.4 % at − 0.2 V versus reversible hydrogen electrode in 0.1 M HCl, superior to most reported CTF-based ones. This work can provide deep insights into the modulation of the electron structure of metal atoms within a porous organic framework for artificial NH3 synthesis through NRR.

Sophisticated construction of single-atom cobalt catalyst based on microbial hyphae for high-performance hydrogenation

Utilizing biomass as a versatile catalyst building platform holds tremendous promise for catalyst design. In this study, we demonstrate a facile and effective method to fabricate high-performance catalysts using Trichoderma afroharzianum hyphae derived carbon fiber (TAHCF) embedded with Co1-N3P1 active sites for nitroaromatic hydrogenation. This strategy leverages the intrinsic self-assembly and metal ion adsorption capabilities of Trichoderma afroharzianum (TA). During the carbonization process, amino acid-rich fungi undergo transformation into biochar substrates co-doped with functional heteroatoms, facilitating the creation of TAHCF single-atom catalyst. Moreover, the catalytic performance can be further enhanced by tailoring the coordination structure of metal atoms on the carbon substrates. Remarkably, we achieve a high turnover frequency of 1553 h−1 for the hydrogenation of nitrobenzene, along with exceptional conversion and selectivity for various nitro compounds with the metal loading as low as 0.02 wt%. Our study presents a characteristic synthetic method that advances the design of single-atom catalysts by leveraging the inherent structure characteristics of biomass in the pursuit of energy sustainability.

Correlation between Heteroatom Coordination and Hydrogen Evolution for Single‐site Pt on Carbon‐based Nanocages

AbstractThe electrocatalytic performance of single‐site catalysts (SSCs) is closely correlated with the electronic structure of metal atoms. Herein we construct a series of Pt SSCs on heteroatom‐doped hierarchical carbon nanocages, which exhibit increasing hydrogen evolution reaction (HER) activities along S‐doped, P‐doped, undoped and N‐doped supports. Theoretical simulation indicates a multi‐H‐atom adsorption process on Pt SSCs due to the low coordination, and a reasonable descriptor is figured out to evaluate the HER activities. Relative to C‐coordinated Pt, N‐coordinated Pt has higher reactivity due to the electron transfer of N‐to‐Pt, which enriches the density of states of Pt 5d orbital near the Fermi level and facilitates the capturing of protons, just the opposite to the situations for P‐ and S‐coordinated ones. The stable N‐coordinated Pt originates from the kinetic stability throughout the multi‐H‐atom adsorption process. This finding provides a significant guidance for rational design of advanced Pt SSCs on carbon‐based supports.

Correlation between Heteroatom Coordination and Hydrogen Evolution for Single-site Pt on Carbon-based Nanocages.

The electrocatalytic performance of single-site catalysts (SSCs) is closely correlated with the electronic structure of metal atoms. Herein we construct a series of Pt SSCs on heteroatom-doped hierarchical carbon nanocages, which exhibit increasing hydrogen evolution reaction (HER) activities along S-doped, P-doped, undoped and N-doped supports. Theoretical simulation indicates a multi-H-atom adsorption process on Pt SSCs due to the low coordination, and a reasonable descriptor is figured out to evaluate the HER activities. Relative to C-coordinated Pt, N-coordinated Pt has higher reactivity due to the electron transfer of N-to-Pt, which enriches the density of states of Pt 5d orbital near the Fermi level and facilitates the capturing of protons, just the opposite to the situations for P- and S-coordinated ones. The stable N-coordinated Pt originates from the kinetic stability throughout the multi-H-atom adsorption process. This finding provides a significant guidance for rational design of advanced Pt SSCs on carbon-based supports.

Efficient detection of carbendazim using an electrochemical sensor for a novel NiFeLDH@HsGY-NH2/MWCNTs heterostructure with lattice-strain.

Carbendazim (CBZ) is widely used for crop protection and its residues threaten human health and the environment. Therefore, developing an effective electrocatalyst is important for the extremely sensitive detection of CBZ. Lattice-strain engineering is an effective strategy to change its electronic structure and ultimately optimize the catalytic performance of materials, which can be used as a modification method to improve the detection performance of electrochemical sensors. Herein, a NiFeLDH@HsGY-NH2/MWCNTs heterojunction with strain effect is prepared by the electrostatic self-assembly method. The structure, morphology, composition, crystallinity and electrochemical performance of NiFeLDH@HsGY-NH2/MWCNTs are analyzed using various instrumental techniques, in which geometric phase analysis (GPA) and X-ray diffraction (XRD) images confirm the lattice-strain generated in NiFeLDH@HsGY-NH2/MWCNTs. The results indicate that the prepared electrochemical sensor exhibited an excellent response for carbendazim (CBZ) in the linear range of 0.05-50.00 μM with a detection limit of 10.00 nM (S/N = 3) under the optimal detection conditions. By analyzing the reasons for the improvement of the catalytic performance of the composite material, it is found that the composite of MWCNTs not only improves the conductivity of NiFeLDH but also regulates the electronic structure of metal atoms through double effects. This study provides new insights into the design of efficient and low-cost catalysts to facilitate electrochemical sensor applications.

Defect Rich Structure Activated 3D Palladium Catalyst for Methanol Oxidation Reaction.

Controlling the structure and properties of catalysts through atomic arrangement is the source of producing a new generation of advanced catalysts. A highly active and stable catalyst in catalytic reactions strongly depends on an ideal arrangement structure of metal atoms. We demonstrated that the introduction of the defect-rich structures, low coordination number (CN), and tensile strain in three-dimensional (3D) urchin-like palladium nanoparticles through chlorine bonded with sp-C in graphdiyne (Pd-UNs/Cl-GDY) can regulate the arrangement of metal atoms in the palladium nanoparticles to form a special structure. In situ Fourier infrared spectroscopy (FTIR) and theoretical calculation results show that Pd-UNs/Cl-GDY catalyst is beneficial to the oxidation and removal of CO intermediates. The Pd-UNs/Cl-GDY for methanol oxidation reaction (MOR) that display high current density (363.6 mA cm-2) and mass activity (3.6 A mgPd-1), 12.0 and 10.9 times higher than Pd nanoparticles, respectively. The Pd-UNs/Cl-GDY catalyst also exhibited robust stability with still retained 95% activity after 2000 cycles. A defects libraries of the face-centered cubic and hexagonal close-packed crystal catalysts (FH-NPs) were synthesized by introducing chlorine in graphdiyne. Such defect-rich structures, low CN, and tensile strain tailoring methods have opened up a new way for the catalytic reaction of MOR.

Defect Rich Structure Activated 3D Palladium Catalyst for Methanol Oxidation Reaction

AbstractControlling the structure and properties of catalysts through atomic arrangement is the source of producing a new generation of advanced catalysts. A highly active and stable catalyst in catalytic reactions strongly depends on an ideal arrangement structure of metal atoms. We demonstrated that the introduction of the defect‐rich structures, low coordination number (CN), and tensile strain in three‐dimensional (3D) urchin‐like palladium nanoparticles through chlorine bonded with sp‐C in graphdiyne (Pd‐UNs/Cl‐GDY) can regulate the arrangement of metal atoms in the palladium nanoparticles to form a special structure. In situ Fourier infrared spectroscopy (FTIR) and theoretical calculation results show that Pd‐UNs/Cl‐GDY catalyst is beneficial to the oxidation and removal of CO intermediates. The Pd‐UNs/Cl‐GDY for methanol oxidation reaction (MOR) that display high current density (363.6 mA cm−2) and mass activity (3.6 A mgPd−1), 12.0 and 10.9 times higher than Pd nanoparticles, respectively. The Pd‐UNs/Cl‐GDY catalyst also exhibited robust stability with still retained 95 % activity after 2000 cycles. A defects libraries of the face‐centered cubic and hexagonal close‐packed crystal catalysts (FH‐NPs) were synthesized by introducing chlorine in graphdiyne. Such defect‐rich structures, low CN, and tensile strain tailoring methods have opened up a new way for the catalytic reaction of MOR.

Regulating the electronic structure through charge redistribution in dense single-atom catalysts for enhanced alkene epoxidation

Inter-site interaction in densely populated single-atom catalysts has been demonstrated to have a crucial role in regulating the electronic structure of metal atoms, and consequently their catalytic performances. We herein report a general and facile strategy for the synthesis of several densely populated single-atom catalysts. Taking cobalt as an example, we further produce a series of Co single-atom catalysts with varying loadings to investigate the influence of density on regulating the electronic structure and catalytic performance in alkene epoxidation with O2. Interestingly, the turnover frequency and mass-specific activity are significantly enhanced by 10 times and 30 times with increasing Co loading from 5.4 wt% to 21.2 wt% in trans-stilbene epoxidation, respectively. Further theoretical studies reveal that the electronic structure of densely populated Co atoms is altered through charge redistribution, resulting in less Bader charger and higher d-band center, which are demonstrated to be more beneficial for the activation of O2 and trans-stilbene. The present study demonstrates a new finding about the site interaction in densely populated single-atom catalysts, shedding insight on how density affects the electronic structure and catalytic performance for alkene epoxidation.

Quantum capacitance modulation of MXenes by metal atoms adsorption

Researchers are committed to finding high-quality electrode materials to improve the performance of supercapacitors. MXenes material has attracted much attention due to its abundant functional groups on the surface. In this paper, the adsorption of H, O, F and OH groups on the surface of Ti3C2 and Ti2C was studied through first-principles calculation. It was found that the optimal adsorption site is directly above the Ti atoms of the middle layer (or the third layer). Al atom shows the best adsorption effect in the adsorption structure of metal atoms. In addition, metal atoms adsorbed on the surface of Ti3C2 and Ti2C structures terminated by F groups were also constructed. Ti3C2F2 adsorbed by Ca atom has obvious advantages under positive potential with the highest quantum capacitance value of 488.153 μF/cm2, which can be used as an ideal cathode material for supercapacitors. Moreover, Li atom adsorbed Ti2CF2 exhibits superior quantum capacitance characteristics at the negative potential.

Engineering Pt Coordination Environment with Atomically Dispersed Transition Metal Sites Toward Superior Hydrogen Evolution

AbstractMetal single‐atom (SA) catalysts have attracted immense attention due to the high catalytic efficiency given by the desired coordination environment of each metal atom. Yet, engineering the local electronic structure of SAs and multi‐atoms (MAs) still remains a challenge. Herein, an atomically dispersed catalyst comprised of Pt SAs, Pt‐Pt/V dual‐atoms, and small clusters supported on a vanadium and nitrogen co‐doped carbon (VNC) (denoted as Pt@VNC) surface is synthesized. In the Pt@VNC, both V and Pt atoms are evenly distributed on the surface of N‐doped carbon, while a few Pt atoms are linked to other Pt atoms via V, forming Pt clusters. The coordination structures of Pt atoms are modulated upon introducing atomically dispersed V sites (which generate small‐sized Pt clusters) and V2O5 clusters, showing extraordinary activity for the hydrogen evolution reaction (HER). Benefiting from the low charge transfer resistance, i.e., fast reaction kinetics, due to the synergistic effect of SAs and clusters, the Pt@VNC demonstrates superior catalytic efficiency and robust durability for the HER. It requires an overpotential of only 5 mV at a current density of 10 mA cm−2 and shows 15 times larger mass activity than the commercial 20 wt.% Pt/C catalyst. This novel catalyst‐design strategy paves a new way for maximizing catalytic efficiency by optimizing the coordination structure of metal atoms.

Entrapping metal atom on hexagonal boron nitride monolayer for high performance single-atom-catalyst: Role of vacancy defects and metal support

In recent time, the research on heterogeneous catalysis has witnessed a stunning progress because of the promising future of single atom catalysis (SAC) with higher activity and selectivity. However, the application of such catalyst in industry remained limited because of its contradicting requirement of stabilizing an atom on a support without affecting its atom-like behavior on the other. Therefore, the search is on to find suitable support and ad-atom combination. Here we report the geometry and electronic structure of metal atom embedded hexagonal boron nitride (h-BN) monolayer, with and without vacancy defects, nano-sheet supported on the copper surface. The effect of vacancy defects has been demonstrated by enhanced binding strength of ad-atoms which in turn paves the way for stabilizing the single atom based catalyst support. In particular, the metal atoms are seen to be more stable on the boron vacancy than nitrogen vacancy site. However, opposite trend has been found for Au doped systems. Further calculations of O2 molecular interaction with Ni and Au embedded h-BN have been carried out to demonstrate the catalytic efficiency of these systems.

Accelerating the oxygen adsorption kinetics to regulate the oxygen reduction catalysis via Fe3C nanoparticles coupled with single Fe-N4 sites

• The single-atom Fe catalyst was synthesized by Fe 3 C|Fe-N 4 coupled sites on 1D and 2D doped-carbon structures. • The formed Fe 3 C|Fe-N 4 sites can positively regulate the electronic structure of the Fe center in the catalyst. • DFT calculations indicate that the adjacent Fe 3 C activated single Fe-N 4 sites accelerate the oxygen adsorption kinetics. • The catalyst assembled ZABs manifested a higher power density and better stability than the Pt/C-based ZABs. Manipulating the electronic structure of Fe-N 4 single-sites to accelerate the oxygen adsorption kinetics is a commendable approach to improve the oxygen reduction reaction (ORR) performance of single-atom Fe catalysts but remains a challenge. Here we propose an endogenous regulation strategy to in situ design the single-atom Fe catalyst (Fe 3 C@NCNTs) derived from 1,8-diaminonaphthalene, iron trichloride, and graphitic carbon nitride via Fe-N 4 single-sites strongly coupled with Fe 3 C nanostructures, in which the combination of 1D and 2D doped-carbon structures and the formation of Fe 3 C|Fe-N 4 coupled sites can endow the catalyst with a considerably enhanced electrocatalytic activity and remarkable cycling stability to the ORR in Zn-air batteries. Theoretical calculations further reveal that endogenous Fe 3 C nanostructures can effectively activate the atomically dispersed Fe-N 4 sites, narrowing the energy barriers of the rate-limiting steps of ORR to promote the ORR catalytic performance. This work provides an effective way to in situ tune the electronic structure of metal atoms to boost the ORR performance of single-atom catalysts for electrochemical energy systems.

Modulating the strong metal-support interaction of single-atom catalysts via vicinal structure decoration

Metal-support interaction predominately determines the electronic structure of metal atoms in single-atom catalysts (SACs), largely affecting their catalytic performance. However, directly tuning the metal-support interaction in oxide supported SACs remains challenging. Here, we report a new strategy to subtly regulate the strong covalent metal-support interaction (CMSI) of Pt/CoFe2O4 SACs by a simple water soaking treatment. Detailed studies reveal that the CMSI is weakened by the bonding of H+, generated from water dissociation, onto the interface of Pt-O-Fe, resulting in reduced charge transfer from metal to support and leading to an increase of C-H bond activation in CH4 combustion by more than 50 folds. This strategy is general and can be extended to other CMSI-existed metal-supported catalysts, providing a powerful tool to modulating the catalytic performance of SACs.

Coadsorption of CO and CH4 on the Au doped SnO2 (110) surface: a first principles investigation

We researched the coadsorption of CO and CH4 molecule on the most stable structure of metal atom (Ni, Ag, Au, Rh, Zn, Pt) doped SnO2 (110) surface with the first principle methods. The formation energy results show that the Au/SnO2 (110) surface is the most stable structure. The adsorption energy, bond length, bond angle, density of states, electron population and charge density difference of gas molecule adsorbed on Au/SnO2 (110) surface are researched, which shows that Au/SnO2 (110) surface have excellent adsorption performance to CO and CH4 molecule. The stable adsorption of double CO on Au/SnO2 (110) surface shows that it has practical value. The research of CO and CH4 coadsorption on Au/SnO2 (110) surface shows that the Au/SnO2 (110) surface has stronger adsorption properties to CO than CH4 molecule. Our research indicates that Au/SnO2 is a potential CO sensor material.

Enhanced oxygen reduction with carbon-polyhedron-supported discrete cobalt-nitrogen sites for Zn-air batteries

• A general strategy to construct discrete Co-N 4 sites confined in carbon polyhedron. • Porous carbon polyhedron with bumpy exterior boosts the exposure of active sites. • Zn acts as sacrificed “shield” to isolate the adjacent Co atoms from aggregating. • Co-N/ZIF-2 catalyst shows high ORR activity superior to commercial Pt/C. • Zn-air battery exhibits high power density of 260 mW cm −2 and stability in 200 h. The specific structure of metal atoms including coordination environment and dispersibility, together with carbon support architecture in metal-nitrogen-carbon (M−N−C) materials are of great importance for their capabilities to catalyze oxygen reduction reaction (ORR). Herein, we report a novel strategy to achieve highly exposed and atomically isolated Co-N 4 active sites within porous carbon polyhedron with bumpy exterior by pyrolysis of predesigned Zn-modified metal–organic frameworks (MOFs) together with tripolycyanmide, during which Zn is evaporated away at high temperature of 900 °C and leaves free vacancies for N to stabilize Co atoms. The bumpy exterior dramatically enlarges its specific surface area and improves the number of active sites. The local structure of single Co atoms coordinated with N is confirmed by combing spherical aberration correction electron microscopy and X-ray absorption fine structure analyses. Remarkably, the obtained Co-N 4 single sites exhibit a high ORR activity with a half-wave potential of 0.861 V that is superior to commercial Pt/C (0.819 V), as well as excellent performance and stability in Zn-air batteries with a peak power density of 260 mW cm −2 . Our work will endow the opportunities to propagate this approach to develop various single-metal-atom materials.

The regulation of coordination structure between cobalt and nitrogen on graphene for efficient bifunctional electrocatalysis in Zn-air batteries

Electrocatalysts with atomically dispersed metal moieties are of importance in enhancing electrocatalysis for a specific reaction including oxygen reduction. However, it is still challenging to modulate the coordination structure of metal atoms with heteroatoms on carbon supports. Herein, an innovative and facile bridging strategy to regulate the coordination structure of cobalt with nitrogen atoms on reduced graphene oxide (rGO) sheets was developed by the interfacial complexation of amino-rich folic acid with cobalt ions on graphene oxide sheets and the subsequent thermal treatment. Typically, the actual coordination interaction between cobalt and nitrogen species was revealed by using X-ray absorption spectroscopy (XAS), exhibiting the Co-N4 coordination structure well-dispersed on reduced graphene oxide. Such unique structure enables the efficient oxygen reduction and evolution reactions via the favorable adsorption and desorption of intermediates. With the enhanced bifunctional electrocatalytic activities, the fabricated Zn-air battery exhibited the excellent performance with large power density of 319.8 mW cm−2 and good long-term stability (over 300 h). This work establishes the synthesis strategy for bridging metal atom with heteroatom on graphene sheets to enhance the bifunctional electrocatalysis toward Zn-air batteries.

Breaking the Limitation of Scaling Relationship By Dual Functions of Adsorbed O Atom on Non-Metal-Element-Doped Single Atom Catalyst

Carbon-based single atom catalysts (SACs) are considered as one of potential catalysts of oxygen reduction reaction (ORR) because of their low cost, high metal atom availability and good CO or methanol tolerance.[ 1] The structure of M-N4 (M is transition metal, such as Fe and Co) has been proved as main active structure of carbon-based N-doped SACs. The efficient strategies on improving their activity are still in short except changing the kind of metal atom. In this DFT work, the influences of non-metal-elements doping (B, N, Si, P, S) on their ORR catalytic activity are studied by density functional theory (DFT). Previous studies simply owed the improved activity to the changing of electronic structure of metal atom, which is not inaccurate. It is revealed that the B doping leads to metal site losing more electrons and N doping works on the contrary. But limited by the scaling relationship, the ORR performance changes little. Interestingly, we find that the Si/P/S site is preferred to be oxidized during ORR. The P/S site would be taken up by O atom and Si sites would be occupied by OH in oxidization process. We find that the local collaborative structures have a great influence on SACs’ ORR performance, which is ignored for a long time. The results not only help understanding the origin and effect of the local collaborative structure on carbon-based SACs, but also provide a guide to the synthesis of carbon-based SACs. Reference [1] C. Zhu, S. Fu, Q. Shi, D. Du, Y. Lin. Angew. Chem. Int. Ed., 2017, 56, 13944. Acknowledgements This work was supported in part by National Natural Science Foundation of China (21975157) and the National Key Research and Development Program of China (2016YFB0101201 and 2016YFB0101312).

A facile and green large-scale fabrication of single atom catalysts for high photocatalytic H2 evolution activity

Atomically dispersed metal catalysts, which have maximized atom utilization efficiencies, have demonstrated high activities for the Hydrogen evolution reaction (HER). However, there is a lack of simple strategies for the preparation of Single-atom catalysts (SACs). Herein, we report a clean and robust electrochemical method for synthesizing a series of SACs. This methodology employs a Carbon nitride (CN) suspension in pure water as a bath solution and a pure metal target as an easily removable precursor instead of a strong ionic electrolyte. The simplicity of this system facilities the large-scale production and direct use of SACs without any subsequent processing. The mass loading of metal atoms is precisely adjusted using the applied electric field intensity and the processing time. We demonstrate the atomic dispersion and the coordination structure of metal atoms in the prepared SACs using aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption spectroscopy. The experimental results show that the Ag1/CN SAC exhibits a higher HER activity than that of Pt nanoparticles on CN, even at low mass loadings. For instance, based on metal loading, Ag1/CN exhibits a record-high photocatalytic HER rate of 1688.9 mmol h−1 g−1metal, much higher than that of Pt nanoparticles (328.5 mmol h−1 g−1metal), which confirms the super-high utilization efficiency of Ag atoms. Density functional theory calculations and experiments suggest that this high photocatalytic activity was attributable to a reduced H2 evolution barrier, good proton adsorption and H2 desorption properties. This work provides a novel approach for the synthesis of durable SACs with excellent photocatalytic activities.

Atomic-Scale Tailoring and Molecular-Level Tracking of Oxygen-Containing Tungsten Single-Atom Catalysts with Enhanced Singlet Oxygen Generation.

The local coordination structure of metal atoms in single-atom catalysts (SACs) greatly influences their catalytic performance. And for most SACs, single metal atoms were anchored on carbon materials with N or C coordination. However, the rational design of oxygen-containing SACs and analyzing its structure-performance relationship remain challenging. Herein, we used amino-rich compounds to tailor the metatungstate and fix the W atoms and finally obtained the oxygen-containing W-SACs. The structural evolution of tungsten and its coordination atoms were tracked by electrospray ionization high-definition mass spectrometry. Furthermore, aberration-corrected transmission electron microscopy, X-ray absorption fine-structure spectroscopy, and first-principles calculation results revealed that different from the traditional SACs, the WO2N2 moiety (W coordinated with two O atoms and two N atoms) may be the favored structure for W species. This special structure promoted the energy transfer for enhancing singlet oxygen generation. This work presents an efficient way to prepare more high-efficiency SACs by atomic-scale tailoring and structural evolution tracking at the molecular level.

Neutron scattering study of tantalum monohydride and monodeuteride

Powder samples of TaH0.89 and TaD0.96 are synthesized under a hydrogen (deuterium) pressure of 2.8 GPa and a temperature of 250 °C, then quenched to the liquid nitrogen temperature, recovered to ambient pressure and studied by neutron diffraction (ND) and inelastic neutron scattering (INS). The ND study shows that both hydrogen and deuterium atoms occupy tetrahedral interstitial sites in a distorted body centered cubic (bcc) crystal structure of metal atoms, while the ordering scenarios in TaH0.89 and TaD0.96 are different. Hydrogen and deuterium atoms are ordered in a layered fashion, forming long period superstructures with space groups P4¯ and P222, respectively, so that the unit cells of the crystal structures of TaH0.89 and TaD0.96 are 2×2×7 and 2×2×8 supercells of the initial cubic unit cell. The INS study demonstrates a pronounced “soft” (trumpet-like) anharmonicity of the potential well for H and D atoms.