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At least 703 records · Page 39
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Cu(TeO3)4 by Materials Project

Cu(TeO3)4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. Cu2+ is bonded in a 3-coordinate geometry to six O2- atoms. There are a spread of Cu–O bond distances ranging from 1.96–2.54 Å. There are four inequivalent Te+5.50+ sites. In the first Te+5.50+ site, Te+5.50+ is bonded to six O2- atoms to form corner-sharing TeO6 octahedra. The corner-sharing octahedra tilt angles range from 32–40°. There are a spread of Te–O bond distances ranging from 1.95–2.05 Å. In the second Te+5.50+ site, Te+5.50+ is bonded to six O2- atoms to form corner-sharing TeO6 octahedra. The corner-sharing octahedra tilt angles range from 35–42°. There are a spread of Te–O bond distances ranging from 1.94–2.06 Å. In the third Te+5.50+ site, Te+5.50+ is bonded to six O2- atoms to form corner-sharing TeO6 octahedra. The corner-sharing octahedra tilt angles range from 32–42°. There are a spread of Te–O bond distances ranging from 1.96–2.03 Å. In the fourth Te+5.50+ site, Te+5.50+ is bonded to six O2- atoms to form corner-sharing TeO6 octahedra. The corner-sharing octahedra tilt angles range from 33–41°. There are a spread of Te–O bond distances ranging from 1.94–2.05 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Cu2+ and two Te+5.50+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two Te+5.50+ atoms. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two Te+5.50+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cu2+ and two Te+5.50+ atoms. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Te+5.50+ atoms. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two Te+5.50+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cu2+ and two Te+5.50+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cu2+ and two Te+5.50+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cu2+ and two Te+5.50+ atoms. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Te+5.50+ atoms. In the eleventh O2- site, O2- is bonded in a distorted T-shaped geometry to one Cu2+ and two Te+5.50+ atoms. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two Te+5.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu(PO3)3 by Materials Project

Cu(PO3)3 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. Cu3+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Cu–O bond distances ranging from 1.99–2.09 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CuO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–49°. There are a spread of P–O bond distances ranging from 1.51–1.61 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CuO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–56°. There is two shorter (1.51 Å) and two longer (1.61 Å) P–O bond length. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CuO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 16–45°. There are a spread of P–O bond distances ranging from 1.49–1.62 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu3+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu3+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the seventh O2- site, O2- is bonded in a distorted linear geometry to one Cu3+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cu3+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu(Mo3Se4)2 by Materials Project

Cu(Mo3Se4)2 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Mo+2.50+ is bonded to five Se2- atoms to form a mixture of edge and corner-sharing MoSe5 square pyramids. There are a spread of Mo–Se bond distances ranging from 2.54–2.64 Å. Cu1+ is bonded in a distorted linear geometry to eight Se2- atoms. There are two shorter (2.34 Å) and six longer (3.29 Å) Cu–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 1-coordinate geometry to three equivalent Mo+2.50+ and one Cu1+ atom. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to four equivalent Mo+2.50+ and one Cu1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu(HgN)2 by Materials Project

Cu(HgN)2 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Cu2+ is bonded in a square co-planar geometry to four N3- atoms. There are two shorter (2.09 Å) and two longer (2.10 Å) Cu–N bond lengths. Hg2+ is bonded in a linear geometry to two N3- atoms. There are one shorter (2.23 Å) and one longer (2.24 Å) Hg–N bond lengths. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a square co-planar geometry to two equivalent Cu2+ and two equivalent Hg2+ atoms. In the second N3- site, N3- is bonded in a square co-planar geometry to two equivalent Cu2+ and two equivalent Hg2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu(AgO)2 by Materials Project

Cu(AgO)2 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Ag1+ is bonded in a linear geometry to two O2- atoms. There are one shorter (2.13 Å) and one longer (2.14 Å) Ag–O bond lengths. Cu2+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (2.02 Å) and two longer (2.03 Å) Cu–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a square co-planar geometry to two equivalent Ag1+ and two equivalent Cu2+ atoms. In the second O2- site, O2- is bonded in a square co-planar geometry to two equivalent Ag1+ and two equivalent Cu2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu(SnS2)4 by Materials Project

Cu(SnS2)4 is beta indium sulfide-derived structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. Cu2+ is bonded to four equivalent S2- atoms to form CuS4 tetrahedra that share corners with twelve equivalent SnS6 octahedra. The corner-sharing octahedral tilt angles are 57°. All Cu–S bond lengths are 2.33 Å. Sn+3.50+ is bonded to six S2- atoms to form SnS6 octahedra that share corners with three equivalent CuS4 tetrahedra and edges with six equivalent SnS6 octahedra. There are three shorter (2.60 Å) and three longer (2.67 Å) Sn–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Cu2+ and three equivalent Sn+3.50+ atoms. In the second S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent Sn+3.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu(N3Cl)2 by Materials Project

Cu(N3Cl)2 crystallizes in the orthorhombic Fmmm space group. The structure is three-dimensional. Cu2+ is bonded in an octahedral geometry to six N atoms. There are a spread of Cu–N bond distances ranging from 1.87–1.93 Å. There are five inequivalent N sites. In the first N site, N is bonded in a single-bond geometry to one Cu2+ and four equivalent Cl1- atoms. There are three shorter (2.71 Å) and one longer (2.72 Å) N–Cl bond lengths. In the second N site, N is bonded in a single-bond geometry to one Cu2+ and four equivalent Cl1- atoms. All N–Cl bond lengths are 2.70 Å. In the third N site, N is bonded in a single-bond geometry to one Cu2+ and four equivalent Cl1- atoms. All N–Cl bond lengths are 2.70 Å. In the fourth N site, N is bonded in a single-bond geometry to one Cu2+ and four equivalent Cl1- atoms. All N–Cl bond lengths are 2.98 Å. In the fifth N site, N is bonded in a single-bond geometry to one Cu2+ and four equivalent Cl1- atoms. All N–Cl bond lengths are 2.98 Å. Cl1- is bonded in a 8-coordinate geometry to twelve N atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu(AgO)2 by Materials Project

Cu(AgO)2 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Ag1+ is bonded in a 4-coordinate geometry to four equivalent O2- atoms. There are two shorter (2.27 Å) and two longer (2.66 Å) Ag–O bond lengths. Cu2+ is bonded in a square co-planar geometry to four equivalent O2- atoms. All Cu–O bond lengths are 1.97 Å. O2- is bonded to four equivalent Ag1+ and two equivalent Cu2+ atoms to form a mixture of distorted corner and edge-sharing OCu2Ag4 octahedra. The corner-sharing octahedra tilt angles range from 0–10°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Prediction of the Al-rich part of the Al-Cu phase diagram using cluster expansion and statistical mechanics

In this work, the thermodynamic properties of α-Al and other phases (GP zones, θ'', θ' and θ) in the Al-rich part of the Al-Cu system have been obtained by means of the cluster expansion formalism in combination with statistical mechanics. This information was used to build the Al-rich part of the Al-Cu phase-diagram taking into account vibrational entropic contributions for θ', as those of the other phases were negligible. The simulation predictions of the phase boundaries between α-Al and either θ'', θ' or θ phases as a function of temperature are in good agreement with experimental data and extend the phase boundaries to a wider temperature range. The DFT calculations reveal the presence of a number of metastable Guinier-Preston-zone type configurations that may coexist with α-Al and θ'' at low temperatures. They also demonstrate that θ' is the stable phase below 550K but it is replaced by θ above this temperature due to the vibrational entropic contribution to the Gibbs energy of θ'. This work shows how the combination of cluster expansion and statistical mechanics can be used to expand our knowledge of the phase diagram of metallic alloys and to provide Gibbs free energies of different phases that can be used as input in mesoscale simulations of precipitation.

36 MATERIALS SCIENCE↗
DOE OSTI2024

The many faces of θ' -Al 2 Cu precipitates: Energetics of pristine and solute segregated Al/ θ' semi-coherent interfaces

θ'-Al 2 Cu precipitates in Al-Cu alloys have various distorted octagon shapes, which can be explained by the competition between {100} and {110} type semi-coherent interfaces with the Al matrix. While most prior studies on the semi-coherent Al/θ' interfaces have focused on the {100} orientation, little is known about the {110} interface. We have investigated the energetics of pristine and solute-segregated {110} semi-coherent Al/θ' interfaces with advanced characterization and first-principles studies. We report interfacial, strain, and solute segregation energetics of the {110} Al/θ' semi-coherent interface for 39 elements and compared them with previously reported values of the {100} interface. We discuss the atomic features and atomic local structures to identify similarities and differences between the two types of Al/θ' semi-coherent interfaces. Here, the isotropy in pristine Al/θ' semi-coherent interfacial energy and the anisotropy resulting from solute segregation provide insight into the formation of different types of θ' precipitate “faces” reported in the literature.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Electrosynthesis of high purity ethylene using high-index facet Cu 2 O nanocrystals electrocatalyst

Electrochemical CO 2 reduction reaction (eCO2RR) to multi-carbon (C 2+ ) products with copper-based catalysts is often limited by poor selectivity. This challenge arises from the concurrent formation of various intermediates, dictated by the atomic arrangement and electronic properties of surface atoms. In this study, we found that copper (I) oxide (Cu 2 O) nanocrystals with 50 facets (50F-NC), predominantly featuring (211) facets that offers high density of under-coordinated sites, demonstrate superior ethylene (C 2 H 4 ) selectivity of 92% ± 2 with an overall current density of 212 mA/cm 2 at -650 mV vs RHE. Furthermore, after one month of storage in a 1 M KOH electrolyte, this catalyst demonstrated a C 2 H 4 Faradaic efficiency of 87% highlighting its stabile structure under strong alkaline environments. Here, operando electrochemical Raman spectroscopy revealed enhanced CO* intermediate coverage on the 50F-NC catalyst, correlating with improved C-C coupling. SEM, TEM, and XPS analyses, along with DFT calculations, suggested that Cu sites on the (211) facet of 50F-NC and those at the Cu/Cu 2 O interface formed in-situ due to the surface reconstruction during the reaction, are likely active sites for effective C-C coupling and sustained high-rate C 2 H 4 production.

Cu nano particle↗
DOE OSTI2021

Pushing Cu uphill of the volcano curve: Impact of a WC support on the catalytic activity of copper toward the hydrogen evolution reaction

Here, the adsorption of atomic H and H 2 on copper mono- and submonolayers supported on hexagonal WC(0001) surfaces has been investigated using density functional theory with the Perdew–Burke–Ernzerhof exchange correlation functional and D2 van der Waals corrections. Results evidence the impact of the termination of the carbide substrate on fundamental properties of Cu adatoms, and, hence, on the stability of molecular and atomic hydrogen, defining copper's catalytic activity for hydrogen evolution reaction. Using H adsorption energy as a descriptor, catalytic activity of Cu adlayers for hydrogen evolution reaction was estimated using traditional volcano curves and a curve, obtained at low hydrogen coverage. Obtained results evidence that copper adlayers supported on the WC may present a viable low-cost alternative to noble metal-based catalysts, with improved catalytic activity compared to that of copper. This, potentially, can be a useful basis for designing and developing novel functional materials with predetermined catalytic properties.

08 HYDROGEN↗
DOE OSTI2023

Influence of electronic transport on electrochemical performance of (Cu,Mn) 3 O 4 solid oxide fuel cell cathodes

Alkaline Earth free spinel oxides provide a potential benefit over Sr-doped perovskite-based materials commonly used as electrodes in high-temperature electrochemical energy conversion devices, e.g., solid oxide fuel cells (SOFCs). Sr-segregation is a known issue leading to performance degradation. In this study, Cu x Mn 3-x O 4 (x = 1, 1.2, and 1.5) porous electrodes were examined as SOFC cathodes using electrochemical impedance spectroscopy to investigate the oxygen reduction reaction (ORR) kinetics in relation to the material's intrinsic conductivity, the extrinsic electrode structure, and the cell test design. Similar to the electronic conducting (La,Sr)MnO 3 SOFC cathodes, the ORR kinetics of Cu x Mn 3-x O 4 spinel electrodes was governed by the oxygen adsorption and diffusion at the particle surface as well as the charge transfer at the triple phase boundaries. The overall electrode polarization resistance was highly dependent on contact density with the metallic current collector, active material particle connectivity, electrode thickness, and the intrinsic electronic materials conductivity. Here, we describe the importance of effective electronic charge transport parallel to the electrode surface in maximizing the electrochemically active electrode volume and enhancing electrode performance. We discuss an approach to optimize cell and electrode design with respect to active materials properties. This aspect is critical to ensure reliable evaluation of new materials, since laboratory-scale button-cells typically exhibit a high degree of electrode microstructure (e.g. porosity, thickness) and electrical contact density variation from sample to sample.

(Cu,Mn)3O4↗
DOE OSTI2023

DFT-based mesoscopic interactions of N adatoms on Cu(100)

The first-principles density functional theory (DFT) method is used to directly calculate the interactions of N atoms of various configurations on Cu(100) surfaces. This allows us to derive a mesoscopic substratemediated interaction model. We find that, for these Cu(100)-supported two-dimensional N clusters, oscillating substrate-mediated interactions obtained from an elastic eigenvector approach including a mesoscopic interacting range (called the mesoscopic model) have reasonable agreement with the DFT results. The DFT periodic boundary conditions are properly mapped into the mesoscopic model. The model is used to analyze the energies of c(2×2) square islands independent of their sizes. Previous experimental studies have shown that, in the low coverage region, N atoms agglomerate to isolated square islands of about 5 nm × 5 nm in size with a c(2×2) structure. With increasing coverage, those islands form regular patterns but do not touch below about 0.4 monolayers. From previous experiments and calculations, the square island pattern shows significant elastic effects which are now confirmed.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2024

Monodisperse Cu Nanoparticles Supported on a Versatile Metal–Organic Framework for Electrocatalytic Reduction of CO 2

Rare-earth metal–organic frameworks (REMOFs) based on polynuclear metal clusters are an emerging class of materials that have shown promise for CO 2 capture and conversion. Here, in this work, copper nanoparticles (CuNPs) were successfully installed on a cluster-based Y(III) MOF to yield a composite material, CuNP-Y-TBAP. The abundance of Cu binding sites on the Y(III) clusters allowed a remarkably high Cu loading to be achieved, and electron microscopy demonstrated that the MOF-supported CuNPs are exceptionally small and monodisperse. CuNP-Y-TBAP was found to be an active heterogeneous catalyst for electrochemical reduction of CO 2 , yielding CO and CH 4 as the primary CO 2 reduction products.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2024

Recovery of p -Hydroxybenzoic Acid from Cu-Catalyzed Alkaline Hydrogen Peroxide Pretreatment of Hybrid Poplar

p-Hydroxybenzoic acid (pHBA) is present in some hardwood biomass feedstocks as an ester attached to the polymeric lignin subunits. Here, we report the isolation and recovery of pHBA from alkaline liquor waste streams obtained from fractionation of hybrid poplar using the “Cu-AHP process”. This process features two stages: alkaline pre-extraction (AP) of the biomass and copper-catalyzed alkaline hydrogen peroxide pretreatment. On a biomass scale of 100 g, 0.5 g of pHBA with a purity of 96% was obtained after decolorization and crystallization. The scalability of the purification process was demonstrated by using liquor obtained from the first-stage AP with 900 g of poplar biomass to afford 3.5 g of crystalline pHBA with 97% purity. Altogether, these results show that pHBA may be isolated and purified from waste streams generated in the two-stage Cu-AHP process without any alteration of the process conditions or impact on carbohydrate and lignin fractionation.

09 BIOMASS FUELS↗
DOE OSTI2022

Contribution of Ryugu-like material to Earth’s volatile inventory by Cu and Zn isotopic analysis

We report initial analyses showed that asteroid Ryugu’s composition is close to CI (Ivuna-like) carbonaceous chondrites (CCs) – the chemically most primitive meteorites, characterized by near-solar abundances for most elements. However, some isotopic signatures (for example, Ti, Cr) overlap with other CC groups, so the details of the link between Ryugu and the CI chondrites are not yet fully clear. Here we show that Ryugu and CI chondrites have the same zinc and copper isotopic composition. As the various chondrite groups have very distinct Zn and Cu isotopic signatures, our results point at a common genetic heritage between Ryugu and CI chondrites, ruling out any affinity with other CC groups. Since Ryugu’s pristine samples match the solar elemental composition for many elements, their Zn and Cu isotopic compositions likely represent the best estimates of the solar composition. Earth’s mass-independent Zn isotopic composition is intermediate between Ryugu/CC and non-carbonaceous chondrites (NCs), suggesting a contribution of Ryugu-like material to Earth’s budgets of Zn and other moderately volatile elements.

58 GEOSCIENCES↗