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Title: Multiscale Morphology of Nanoporous Copper Made from Intermetallic Phases

Authors:
 [1]; ORCiD logo; ;  [1]; ;  [1]; ORCiD logo; ;  [1]
  1. Nanoscale Synthesis and Characterization Laboratory, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Integrated Mesoscale Architectures for Sustainable Catalysis (IMASC)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1389016
DOE Contract Number:
SC0012573
Resource Type:
Journal Article
Resource Relation:
Journal Name: ACS Applied Materials and Interfaces; Journal Volume: 9; Journal Issue: 30; Related Information: IMASC partners with Harvard University (lead); Fritz Haber Institute; Lawrence Berkeley National Laboratory; Lawrence Livermore National Laboratory; University of Kansas; Tufts University
Country of Publication:
United States
Language:
English
Subject:
catalysis (heterogeneous), mesostructured materials, materials and chemistry by design, synthesis (novel materials)

Citation Formats

Egle, Tobias, Barroo, Cédric, Janvelyan, Nare, Baumgaertel, Andreas C., Akey, Austin J., Biener, Monika M., Friend, Cynthia M., Bell, David C., and Biener, Juergen. Multiscale Morphology of Nanoporous Copper Made from Intermetallic Phases. United States: N. p., 2017. Web. doi:10.1021/acsami.7b05648.
Egle, Tobias, Barroo, Cédric, Janvelyan, Nare, Baumgaertel, Andreas C., Akey, Austin J., Biener, Monika M., Friend, Cynthia M., Bell, David C., & Biener, Juergen. Multiscale Morphology of Nanoporous Copper Made from Intermetallic Phases. United States. doi:10.1021/acsami.7b05648.
Egle, Tobias, Barroo, Cédric, Janvelyan, Nare, Baumgaertel, Andreas C., Akey, Austin J., Biener, Monika M., Friend, Cynthia M., Bell, David C., and Biener, Juergen. 2017. "Multiscale Morphology of Nanoporous Copper Made from Intermetallic Phases". United States. doi:10.1021/acsami.7b05648.
@article{osti_1389016,
title = {Multiscale Morphology of Nanoporous Copper Made from Intermetallic Phases},
author = {Egle, Tobias and Barroo, Cédric and Janvelyan, Nare and Baumgaertel, Andreas C. and Akey, Austin J. and Biener, Monika M. and Friend, Cynthia M. and Bell, David C. and Biener, Juergen},
abstractNote = {},
doi = {10.1021/acsami.7b05648},
journal = {ACS Applied Materials and Interfaces},
number = 30,
volume = 9,
place = {United States},
year = 2017,
month = 7
}
  • Many application-relevant properties of nanoporous metals critically depend on their multiscale architecture. For example, the intrinsically high step-edge density of curved surfaces at the nanoscale provides highly reactive sites for catalysis, whereas the macroscale pore and grain morphology determines the macroscopic properties, such as mass transport, electrical conductivity, or mechanical properties. Here, in this work, we systematically study the effects of alloy composition and dealloying conditions on the multiscale morphology of nanoporous copper (np-Cu) made from various commercial Zn–Cu precursor alloys. Using a combination of X-ray diffraction, electron backscatter diffraction, and focused ion beam cross-sectional analysis, our results reveal thatmore » the macroscopic grain structure of the starting alloy surprisingly survives the dealloying process, despite a change in crystal structure from body-centered cubic (Zn–Cu starting alloy) to face-centered cubic (Cu). The nanoscale structure can be controlled by the acid used for dealloying with HCl leading to a larger and more faceted ligament morphology compared to that of H 3PO 4. Finally, anhydrous ethanol dehydrogenation was used as a probe reaction to test the effect of the nanoscale ligament morphology on the apparent activation energy of the reaction.« less
  • A multiscale model was developed to simulate the formation of Fe-rich intermetallics and pores in quaternary Al-Si-Cu-Fe alloys. At the microscale, the multicomponent diffusion equations were solved for multiphase (liquid-solid-gas) materials via a finite difference framework to predict microstructure formation. A fast and robust decentered plate algorithm was developed to simulate the strong anisotropy of the solid/liquid interfacial energy for the Fe-rich intermetallic phase. The growth of porosity was controlled by local pressure drop due to solidification and interactions with surrounding solid phases, in addition to hydrogen diffusion. The microscale model was implemented as a subroutine in a commercial finitemore » element package, producing a coupled multiscale model. This allows the influence of varying casting conditions on the Fe-rich intermetallics, the pores, and their interactions to be predicted. Synchrotron x-ray tomography experiments were performed to validate the model by comparing the three-dimensional morphology and size distribution of Fe-rich intermetallics as a function of Fe content. Large platelike Fe-rich {beta} intermetallics were successfully simulated by the multiscale model and their influence on pore size distribution in shape castings was predicted as a function of casting conditions.« less
  • The structure of a new naturally-occurring nanoporous copper silicate of formula Na{sub 2}CaCu{sub 2}Si{sub 8}O{sub 20}·H{sub 2}O (disodium calcium dicopper octasilicate monohydrate) is reported and its relations to synthetic nanoporous “CuSH” compounds are discussed. The new phase is monoclinic C2/m with unit cell parameters a=12.2439(6) Å, b=15.7514(4) Å, c=10.6008(3) Å, β=125.623(2)°, and V=1661.87(10) Å{sup 3} (Z=4). The structure has been refined to R{sub 1}(all)=0.033, wR{sub 2}(all)=0.071, and GoF=1.090. In the double-sheet of SiO{sub 4} tetrahedra, 6{sup 4}8{sup 2} cages connect to form a chequer-board motif within which Na atoms and H{sub 2}O groups occupy channels. Each cage is occupied bymore » 7-coordinated Na atom lying in a mirror plane. An intra-sheet corridor between the 6{sup 4}8{sup 2} cages is occupied by Na in 8-fold cuboidal coordination. The silicate skeleton is highly porous, with obvious channels and pathways for ion migration. The interlayer between double-sheets is occupied by CaO{sub 8}, CuO{sub 5} and NaO{sub 5}(H{sub 2}O) polyhedra. CuO{sub 5} polyhedra occur as rows of edge-sharing Cu{sub 2}O{sub 9} pairs connected by NaO{sub 5}(H{sub 2}O) octahedra and CaO{sub 8} square antiprisms. Both CuO{sub 5} and NaO{sub 5}(H{sub 2}O) polyhedra are features shared with closely-related synthetic “CuSH” phases of interest to the solid-state chemistry community as potential nanoporous catalysts. However, Na{sub 2}CaCu{sub 2}Si{sub 8}O{sub 20}·H{sub 2}O is the only natural representative of this group of structures, and the only one to contain essential Ca. The discovery of Na{sub 2}CaCu{sub 2}Si{sub 8}O{sub 20}·H{sub 2}O points to a new group of CuSH-type phases containing alkaline-earth elements. Its close natural association and structural affinity with wesselsite SrCuSi{sub 4}O{sub 10} suggest the possibility of transformation between CuSH and gillespite-type phases, and thereby a route to synthesising alkaline-earth CuSH derivatives, so widening their potential as nanoporous catalysts. - Graphical abstract: Projection onto (010) of the structure of the natural nanoporous sheet silicate Na{sub 2}CaCu{sub 2}Si{sub 8}O{sub 20}·H{sub 2}O showing the double sheet of corner-linked SiO{sub 4} tetrahedra, intralayer Na and interlayer Na, Ca Cu and H{sub 2}O. Small green sphere Cu, large blue spheres Ca, orange purple and yellow small spheres Na, large grey sphere H{sub 2}O molecules. Bonds from inter/intralayer species to sheets have been omitted for clarity. - Highlights: • A new naturally-occurring nanoporous Cu sheet–silicate containing 6{sup 4}8{sup 2} cages. • A bridge between synthetic nanoporous CuSH phases and gillespite-type.« less
  • Here, we report the fabrication of ultrathin, nanoporous silicon nitride membranes made from templates of regular, nanoscale features in self-assembled block copolymer thin films. The inorganic membranes feature thicknesses less than 50 nm and volume porosities over 30%, with straight-through pores that offer high throughout for gas transport and separation applications. As fabricated, the pores are uniformly around 20 nm in diameter, but they can be controllably and continuously tuned to single-digit nanometer dimensions by atomic layer deposition of conformal coatings. A deviation from expected Knudsen diffusion is revealed for transport characteristics of saturated vapors of organic solvents across themore » membrane, which becomes more significant for membranes of smaller pores. We attribute this to capillary condensation of saturated vapors within membrane pores, which reduces membrane throughput by over 1 order of magnitude but significantly improves the membrane’s selectivity. Between vapors of acetone and ethyl acetate, we measure selectivities as high as 7:1 at ambient pressure and temperature, 4 times more than the Knudsen selectivity.« less
  • The essential trace metal copper has been identified as a pollutant of concern by the Environmental Protection Agency (EPA) because of its widespread occurrence in the environment, often being found in concentrations capable of causing problems in organisms in that ecosystem. In this work, three different nanoporous sorbents containing chelating diamine functionalities were evaluated for Cu2+ adsorption in natural waters; these sorbents are ethylenediamine functionalized self-assembled monolayers on mesoporous supports (EDA-SAMMS®, SAMMS is a registered trademark of Steward Advanced Materials), ethylenediamine functionalized activated carbon (AC-CH2-EDA), and 1,10-Phenanthroline functionalized mesoporous carbon (Phen-FMC). The pH dependence of Cu2+ sorption and the Cu2+more » sorption capacities of sorbents were determined. The Cu2+ adsorption rates and metal ion selectivity of these sorbents were compared to those of commercial sorbents (Chelex-100 ion exchange resin and Darco KB-B activated carbon). All three chelating diamine sorbents showed the excellent Cu2+ removal (~ 95-99%) from river water and sea water over the pH range of 6.0-8.0. Even under acidic conditions (e.g. pH of 3), AC-CH2-EDA and Phen-FMC were able to remove approximately ~49-58% of Cu2+ in sea water. EDA-SAMMS and AC-CH2-EDA demonstrated rapid Cu2+ sorption kinetics (reaching equilibrium within 5 min) and large adsorption capacities (26 and 17 mg Cu/g sorbent, respectively) in sea water. They also showed good selectivity for Cu2+ over other metal ions (e.g. Ca2+, Fe2+, Ni2+, and Zn2+) in sea water.« less