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DOE OSTI2020

Materials Data on Co(HO)2 by Materials Project

Co(OH)2 crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of one Co(OH)2 sheet oriented in the (0, 0, 1) direction. Co2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Co–O bond distances ranging from 2.04–2.12 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Co2+ and one H1+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Co2+ and one H1+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Co(HO)2 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Co(HO)2 by Materials Project

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Co(HO)2 by Materials Project

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Co(HO)2 by Materials Project

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Co(HO)2 by Materials Project

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Co(HO)2 by Materials Project

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Co(HO)2 by Materials Project

36 MATERIALS SCIENCE↗

DOE OSTI2025

Active Sites in the Dealuminated Beta Zeolite-Supported Cobalt Catalyst for Non-Oxidative Ethane Dehydrogenation

Dispersed metal species in siliceous zeolites have been actively studied for non-oxidative dehydrogenation of ethane (NDE). Fundamental insights into the dynamics of metal species in zeolites under reaction conditions have rarely been explored. Herein, we report an atomic level understanding of the dynamics and activity of cobalt (Co) sites in dealuminated Beta zeolite (DeAl-BEA) for NDE during induction and reaction conditions with extensive characterization techniques such as diffuse reflectance UV–vis, solid state nuclear magnetic resonance and X-ray photoelectron, X-ray diffraction along with in situ Fourier transform infrared and X-ray absorption spectroscopy. For a catalyst with 0.5 mass % Co loading, tetrahedral Co 2+ mononuclear sites, di-coordinated to the zeolite framework and with two silanol groups in vicinity (i.e., (≡SiO) 2 Co(HO–Si≡) 2 ), form upon exposure to hydrogen during induction and persist through the NDE reaction. Increasing the Co loading to 3.0 mass % yielded Co sites with similar electronic and coordination structures but slightly elongated Co–O bonds. Upon cooling to room temperature, the Co sites persisted in the same coordination environment, though the disappearance of a feature in the Co K-edge near-edge region revealed changes in the active site’s electronic structure coinciding with modest shifts in bond lengths. The electronic structure and activity of (≡SiO) 2 Co(HO–Si≡) 2 sites were studied comparatively to a few other hypothetical Co 2+ coordination structures, using electronic structure calculations and microkinetic simulations. The simulations showed that NDE is controlled by β-hydride elimination following C–H bond activation and that Co-sites possessing flexibility because of neighboring silanol defects are more active. Interestingly, dinuclear Co–O–Co sites (i.e., (≡SiO)Co(HO–Si≡) 2 –O–(HO–Si≡) 2 Co(≡SiO)) were more active than the mononuclear (≡SiO) 2 Co(HO–Si≡) 2 sites because of favorable hydrogen bonding with the vicinal silanol groups. In conclusion, the present study bridges the gap between the knowledge acquired by ex-situ characterizations and the active sites under the reaction conditions in alkane dehydrogenation chemistry.

36 MATERIALS SCIENCE↗

DOE OSTI2022

Kinetics and selectivity of methane oxidation on an IrO 2 (110) film

Undercoordinated, bridging O-atoms (O br ) are highly active as H-acceptors in alkane dehydrogenation on IrO 2 (110) surfaces but transform to HO br groups that are inactive toward hydrocarbons. The low C–H activity and high stability of the HO br groups cause the kinetics and product selectivity during CH 4 oxidation on IrO 2 (110) to depend sensitively on the availability of O br atoms prior to the onset of product desorption. From temperature programmed reaction spectroscopy (TPRS) and kinetic simulations, we identified two O br -coverage regimes that distinguish the kinetics and product formation during CH 4 oxidation on IrO 2 (110). Under excess O br conditions, when the initial O br coverage is greater than that needed to oxidize all the CH 4 to CO 2 and HO br groups, complete CH 4 oxidation is dominant and produces CO 2 in a single TPRS peak between 450 and 500 K. However, under O br -limited conditions, nearly all the initial O br atoms are deactivated by conversion to HO br or abstracted after only a fraction of the initially adsorbed CH 4 oxidizes to CO 2 and CO below 500 K. Thereafter, some of the excess CH x groups abstract H and desorb as CH 4 above ~500 K while the remainder oxidize to CO 2 and CO at a rate that is controlled by the rate at which Obr atoms are regenerated from HObr during the formation of CH 4 and H 2 O products. We also show that chemisorbed O-atoms ('on-top O') on IrO 2 (110) enhance CO 2 production below 500 K by efficiently abstracting H from Obr atoms and thereby increasing the coverage of O br atoms available to completely oxidize CH x groups at low temperature. Furthermore, our results provide new insights for understanding factors which govern the kinetics and selectivity during CH 4 oxidation on IrO 2 (110) surfaces.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2020

Simulated production of OH, HO 2 , CH 2 O, and CO 2 during dilute fuel oxidation can predict 1st-stage ignition delays

Chemical kinetics simulations are used to explore whether detailed measurements of relevant chemical species during the oxidation of very dilute fuels (less than 1 Torr partial pressure) in a high-pressure plug flow reactor (PFR) can predict autoignition propensity. We find that for many fuels the timescale for the onset of spontaneous oxidation in dilute fuel/air mixtures in a simple PFR is similar to the 1st-stage ignition delay time (IDT) at stoichiometric engine-relevant conditions. For those fuels that deviate from this simple trend, the deviation is closely related to the peak rate of production of OH, HO 2 , CH 2 O, and CO 2 formed during oxidation. We use these insights to show that an accurate correlation between simulated profiles of these species in a PFR and 1st-stage IDT can be developed using convolutional neural networks. Our simulations suggest that the accuracy of such a correlation is 10–50%, which is appropriate for rapid fuel screening and may be sufficient for predictive fuel performance modeling.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2020

Materials Data on CoH8Se2(ClO4)2 by Materials Project

Co(HO)4H2O2(HSeOCl)2 crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of four water molecules; four HSeOCl clusters; and two Co(HO)4 ribbons oriented in the (1, 0, 0) direction. In each HSeOCl cluster, H1+ is bonded in a single-bond geometry to one Se4+ atom. The H–Se bond length is 1.52 Å. Se4+ is bonded in a distorted trigonal non-coplanar geometry to one H1+, one O2-, and one Cl1- atom. The Se–O bond length is 1.66 Å. The Se–Cl bond length is 2.31 Å. O2- is bonded in a single-bond geometry to one Se4+ atom. Cl1- is bonded in a single-bond geometry to one Se4+ atom. In each Co(HO)4 ribbon, Co2+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are two shorter (1.93 Å) and two longer (2.10 Å) Co–O bond lengths. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.04 Å) and one longer (1.51 Å) H–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to one Co2+ and two H1+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Co2+ and one H1+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ho2Co17 by Materials Project

Ho2Co17 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded in a 12-coordinate geometry to eighteen Co atoms. There are a spread of Ho–Co bond distances ranging from 2.93–3.25 Å. In the second Ho site, Ho is bonded in a 2-coordinate geometry to twenty Co atoms. There are a spread of Ho–Co bond distances ranging from 2.88–3.13 Å. There are four inequivalent Co sites. In the first Co site, Co is bonded in a 2-coordinate geometry to one Ho and thirteen Co atoms. There are a spread of Co–Co bond distances ranging from 2.32–2.67 Å. In the second Co site, Co is bonded to two equivalent Ho and ten Co atoms to form CoHo2Co10 cuboctahedra that share corners with fourteen CoHo2Co10 cuboctahedra, edges with six equivalent CoHo3Co9 cuboctahedra, and faces with ten CoHo2Co10 cuboctahedra. There are four shorter (2.39 Å) and four longer (2.40 Å) Co–Co bond lengths. In the third Co site, Co is bonded in a 12-coordinate geometry to two Ho and ten Co atoms. There are a spread of Co–Co bond distances ranging from 2.34–2.54 Å. In the fourth Co site, Co is bonded to three Ho and nine Co atoms to form a mixture of distorted face, edge, and corner-sharing CoHo3Co9 cuboctahedra. Both Co–Co bond lengths are 2.41 Å.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Fast Advective Water Flow through Nanochannels in Clay Interlayers: Implications for Moisture Transport in Soils and Unconventional Oil/Gas Production

Water flow in nanometer or sub-nanometer hydrophilic channels bears special importance in diverse fields of science and engineering. However, the nature of such water flow remains elusive. In this work, we report our molecular-modeling results on water flow in a sub-nanometer clay interlayer between two montmorillonite layers. We show that a fast advective flow can be induced by evaporation at one end of the interlayer channel, that is, a large suction pressure created by evaporation (~818 MPa) is able to drive the fast water flow through the channel (~0.88 m/s for a 46 Å-long channel). Scaled up for the pressure gradient to a 2 μm particle, the velocity of water is estimated to be about 95 μm/s, indicating that water can quickly flow through a μm-sized clay particle within seconds. The prediction seems to be confirmed by our thermogravimetric analysis of bentonite hydration and dehydration processes, which indicates that water transport at the early stage of the dehydration is a fast advective process, followed by a slow diffusion process. The possible occurrence of a fast advective water flow in clay interlayers prompts us to reassess water transport in a broad set of natural and engineered systems such as clay swelling/shrinking, moisture transport in soils, water uptake by plants, water imbibition/release in unconventional hydrocarbon reservoirs, and cap rock integrity of supercritical CO 2 storage.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2020

Experimental Evidence of Dioxole Unimolecular Decay Pathway for Isoprene-Derived Criegee Intermediates

Ozonolysis of isoprene, one of the most abundant volatile organic compounds emitted into the Earth’s atmosphere, generates two four-carbon unsaturated Criegee intermediates, methyl vinyl ketone oxide (MVK-oxide) and methacrolein oxide (MACR-oxide). The extended conjugation between the vinyl substituent and carbonyl oxide groups of these Criegee intermediates facilitates rapid electrocyclic ring closures that form 5-membered cyclic peroxides, known as dioxoles. This research discusses the first experimental evidence of this novel decay pathway, which is predicted to be the dominant atmospheric sink for specific conformational forms of MVK-oxide (anti) and MACR-oxide (syn) with the vinyl substituent adjacent to the terminal O atom. The resulting dioxoles are predicted to undergo rapid unimolecular decay to oxygenated hydrocarbon radical products, including acetyl, vinoxy, formyl, and 2-methyl-vinoxy radicals. In the presence of O 2 , these radicals rapidly react to form peroxy radicals (ROO), which quickly decay via carbon-centered radical intermediates (QOOH) to stable carbonyl products that are identified in this work. The carbonyl products are detected under thermal conditions (298 K, 10 torr He) using multiplexed photoionization mass spectrometry (MPIMS). The main products (and associated relative abundances) originating from unimolecular decay of anti-MVK-oxide and subsequent reaction with O 2 are formaldehyde (88 ± 5%), ketene (9 ± 1%) and glyoxal (3 ± 1%). Those identified from the unimolecular decay of syn-MACR-oxide and subsequent reaction of O 2 are acetaldehyde (37 ± 7%), vinyl alcohol (9 ± 1%), methylketene (2 ± 1%), and acrolein (52 ± 5%). In addition to the stable carbonyl products, the secondary peroxy chemistry also generates OH or HO 2 radical co-products.

09 BIOMASS FUELS↗

DOE OSTI2020

Materials Data on Ho12Co5Bi by Materials Project

Ho12Co5Bi crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. there are three inequivalent Ho sites. In the first Ho site, Ho is bonded in a 5-coordinate geometry to four Co and one Bi atom. There are a spread of Ho–Co bond distances ranging from 2.87–3.23 Å. The Ho–Bi bond length is 3.60 Å. In the second Ho site, Ho is bonded in a 4-coordinate geometry to three Co and one Bi atom. There are one shorter (2.67 Å) and two longer (2.84 Å) Ho–Co bond lengths. The Ho–Bi bond length is 3.43 Å. In the third Ho site, Ho is bonded in a 4-coordinate geometry to three Co and one Bi atom. There are a spread of Ho–Co bond distances ranging from 2.67–3.35 Å. The Ho–Bi bond length is 3.40 Å. There are three inequivalent Co sites. In the first Co site, Co is bonded in a 9-coordinate geometry to eight Ho and one Co atom. The Co–Co bond length is 2.34 Å. In the second Co site, Co is bonded in a 2-coordinate geometry to eight Ho and one Co atom. The Co–Co bond length is 2.21 Å. In the third Co site, Co is bonded in a distorted body-centered cubic geometry to eight Ho atoms. Bi is bonded in a cuboctahedral geometry to twelve Ho atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ho6Co2Sn by Materials Project

Ho6Co2Sn crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. there are three inequivalent Ho sites. In the first Ho site, Ho is bonded in a 4-coordinate geometry to two Co and two Sn atoms. There are one shorter (2.71 Å) and one longer (3.15 Å) Ho–Co bond lengths. There are one shorter (3.07 Å) and one longer (3.31 Å) Ho–Sn bond lengths. In the second Ho site, Ho is bonded in a 5-coordinate geometry to three Co and two Sn atoms. There are two shorter (2.90 Å) and one longer (3.13 Å) Ho–Co bond lengths. There are one shorter (3.20 Å) and one longer (3.62 Å) Ho–Sn bond lengths. In the third Ho site, Ho is bonded in a 4-coordinate geometry to three Co and one Sn atom. There are one shorter (2.72 Å) and two longer (2.85 Å) Ho–Co bond lengths. The Ho–Sn bond length is 3.39 Å. There are two inequivalent Co sites. In the first Co site, Co is bonded in a 2-coordinate geometry to eight Ho and one Co atom. The Co–Co bond length is 2.72 Å. In the second Co site, Co is bonded in a 9-coordinate geometry to eight Ho and one Co atom. The Co–Co bond length is 2.24 Å. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded in a cuboctahedral geometry to twelve Ho atoms. In the second Sn site, Sn is bonded in a body-centered cubic geometry to eight Ho atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ho2Co12Ni5 by Materials Project

Ho2Co12Ni5 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded in a 12-coordinate geometry to eighteen Co atoms. There are a spread of Ho–Co bond distances ranging from 2.94–3.20 Å. In the second Ho site, Ho is bonded in a 2-coordinate geometry to twelve Co and eight Ni atoms. There are six shorter (3.01 Å) and six longer (3.05 Å) Ho–Co bond lengths. There are two shorter (2.80 Å) and six longer (3.12 Å) Ho–Ni bond lengths. There are two inequivalent Co sites. In the first Co site, Co is bonded to two Ho, six Co, and four Ni atoms to form distorted CoHo2Co6Ni4 cuboctahedra that share corners with four equivalent NiHo2Co8Ni2 cuboctahedra, corners with twenty CoHo2Co6Ni4 cuboctahedra, edges with two equivalent NiHo2Co8Ni2 cuboctahedra, edges with three CoHo3Co6Ni3 cuboctahedra, faces with four equivalent NiHo2Co8Ni2 cuboctahedra, and faces with seventeen CoHo2Co6Ni4 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.30–2.53 Å. There are two shorter (2.38 Å) and two longer (2.67 Å) Co–Ni bond lengths. In the second Co site, Co is bonded to three Ho, six Co, and three Ni atoms to form distorted CoHo3Co6Ni3 cuboctahedra that share corners with five equivalent NiHo2Co8Ni2 cuboctahedra, corners with eighteen CoHo3Co6Ni3 cuboctahedra, edges with three equivalent NiHo2Co8Ni2 cuboctahedra, edges with seven CoHo3Co6Ni3 cuboctahedra, faces with two equivalent NiHo2Co8Ni2 cuboctahedra, and faces with eighteen CoHo2Co6Ni4 cuboctahedra. Both Co–Co bond lengths are 2.36 Å. There are two shorter (2.43 Å) and one longer (2.65 Å) Co–Ni bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded to two equivalent Ho, eight Co, and two equivalent Ni atoms to form NiHo2Co8Ni2 cuboctahedra that share corners with four equivalent NiHo2Co8Ni2 cuboctahedra, corners with eighteen CoHo3Co6Ni3 cuboctahedra, edges with ten CoHo3Co6Ni3 cuboctahedra, faces with six equivalent NiHo2Co8Ni2 cuboctahedra, and faces with twelve CoHo2Co6Ni4 cuboctahedra. Both Ni–Ni bond lengths are 2.52 Å. In the second Ni site, Ni is bonded in a 1-coordinate geometry to one Ho, nine Co, and four Ni atoms. The Ni–Ni bond length is 2.42 Å.

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