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At least 1,225 records · Page 68

A novel catalytic method for low-energy CO2 capture

High-energy associated with slow absorption-desorption kinetics remains a major challenge of all chemisorption-based CO2 capture technologies, particularly during solvent regeneration. A novel catalytic sorption system, based on aqueous piperidine (C5H10-NH) activated by a deep eutectic solvent (DES), was developed in this research to overcome the challenge.

CO2 capture↗

Cooperative Effects Associated with High Electrolyte Concentrations in Driving the Conversion of CO2 to C2H4 on Copper

Compared to a conventional electrolyte concentration of 1 M HCOOK, the use of a highly concentrated 7.1 M HCOOK electrolyte increases the Faradaic efficiency (FE) ratio of C2H4/CO from 2.2 +- 0.3 to 18.3 +- 4.8 at -1.08 V vs. reversible hydrogen electrode (RHE) on a Cu gas-diffusion electrode. Based on electrochemical analysis and ab initio molecular dynamics (AIMD) simulation, the identity and concentration of the cation and anion play more important roles in controlling the CO2R reaction pathway than the bulk CO2 solubility and the bulk pH of electrolytes. In situ attenuated reflectance surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) suggests that, unlike 1 M HCOOK, the *CO-bridge-binding mode on Cu is dominant in 7.1 M HCOOK electrolyte, which potentially results in less CO release and higher yield of C2H4. This study demonstrates that although we can tailor the electrolyte composition to shift product selectivity, the factors that control the product selectivity are numerous and cannot be distilled down into one correlated property-reactivity relationship.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

CO 2 utilization in built environment via the P CO 2 swing carbonation of alkaline solid wastes with different mineralogy

Carbon mineralization to solid carbonates is one of the reaction pathways that can not only utilize captured CO 2 but also potentially store it in the long term. In this study, the dissolution and carbonation behaviors of alkaline solid wastes (i.e., waste concrete) was investigated. Concrete is one of the main contributors to a large carbon emission in the built environment. Thus, the upcycling of waste concrete via CO 2 utilization has multifaceted environmental benefits including CO 2 emission reduction, waste management and reduced mining. Unlike natural silicate minerals such as olivine and serpentine, alkaline solid wastes including waste concrete are highly reactive, and thus, their dissolution and carbonation behaviors vary significantly. Here, both conventional acid (e.g., hydrochloric acid) and less studied carbonic acid (i.e., CO 2 saturated water) solvent systems were explored to extract Ca from concrete. Non-stoichiometric dissolution behaviors between Ca and Si were confirmed under far-from-equilibrium conditions (0.1 wt% slurry density), and the re-precipitation of the extracted Si was observed at near-equilibrium conditions (5 wt% slurry density), when the Ca extraction was performed at a controlled pH of 3. These experiments, with a wide range of slurry densities, provided valuable insight into Si re-precipitation phenomena and its effect on the mass transfer limitation during concrete dissolution. Next, the use of the partial pressure of CO 2 for the pH swing carbon mineralization process was investigated for concrete, and the results were compared to those of Mg-bearing silicate minerals. In the P CO 2 swing process, the extraction of Ca was significantly limited by the precipitation of the carbonate phase (i.e., calcite), since CO 2 bubbling could not provide a low enough pH condition for concrete–water–CO 2 systems. Furthermore, this study showed that the two-step carbon mineralization via P CO 2 swing, that has been developed for Mg-bearing silicate minerals, may not be viable for highly reactive Ca-bearing silicate materials (e.g., concrete). The precipitated calcium carbonate (PCC) derived from waste concrete via a pH swing process showed very promising results with a high CO 2 utilization potential as an upcycled construction material.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Verification and Validation of Spectral Element Code for Supercritical CO2 Flow in Vertical Heated Tubes

The investigation of heat transfer in supercritical CO2 (sCO2) has garnered considerable attention in recent decades, given sCO2's potential as a promising working fluid for advanced power conversion cycles. Despite previous research efforts, there are still gaps in our understanding of sCO2 heat transfer, particularly in conditions associated with heat transfer deterioration. To delve into sCO2 heat transfer more comprehensively, we propose employing the high-fidelity computational fluid dynamics code NekRS to simulate sCO2 flow using the large eddy simulation technique. Through graphics processing unit acceleration, NekRS achieves a higher computational speed than traditional CPU-based systems. However, before using NekRS in practical applications involving sCO2, it is imperative to perform verification and validation. Here, this paper presents our efforts to verify and validate the NekRS code's capability for simulating sCO2 using heated vertical tubes, where heat transfer deterioration usually happens. To accommodate the unique properties of sCO2, we have modified the NekRS code by integrating third-party property modules, such as REFPROP and PROPATH. Our simulations are compared with experimental and numerical data from the literature, instilling confidence in leveraging NekRS for future engineering applications. Our simulations also reveal that the accuracy of the property module significantly impacts the results, with REFPROP outperforming PROPATH for sCO2 properties. Additionally, we observed that, depending on the flow direction, buoyancy can either enhance or suppress turbulence in sCO2 flow. In upward flow, under certain conditions, the suppressed turbulence leads to heat transfer deterioration, resulting in elevated wall temperatures.

NekRS↗

Hestia-SWIFL: hourly anthropogenic fossil fuel CO2 and heat on the 2km WRF grid, version 1.1

The Hestia-SWIFL version 1.1 anthropogenic heat (AH) and fossil fuel CO2 (FFCO2) emissions data product represent emissions due to the combustion of fossil fuel and cement production within the state of Arizona from 2019 to 2022. This product was developed as part of the Southwest Urban Corridor Integrated Field Laboratory (SW-IFL) project, which aims to provide new knowledge and tools that address extreme heat, air quality, climate change and related urban environmental issues by integrating high-resolution observations, modeling, and civic engagement. The emissions are generated using a bottom-up/engineering approach and are tied to results generated by the Vulcan Project version 4, an effort to quantify space/time-resolved FFCO2 & AH emissions for the entire United States landscape. A large number of data sources are combined to best estimate the emissions at fine scales such as air quality emissions data, traffic flow data, building information, sociodemographic information, and fuel statistics. The AH product provides emissions for two emissions sources (transportation and point source emissions) in units of Watts per hour per square meter (W/m2) per year (annual files) or per hour (hourly files). The FFCO2 product provides emissions from nine individual emission sectors as well as the total, and in units of tons of carbon (tC) per grid cell per year or per hour. The output made available here places the native spatial resolution of the Hestia FFCO2 & AH emissions data product (points, lines, and polygons) into a regularized 2km x 2km grid at hourly and annual temporal resolutions, and stored in netCDF files. The exact spatial extent is defined by the ASU Weather Research Forecast (WRF) simulation grid. All data are processed using R/Python pm high-performance computing system. 2-27-2026 updates: Bugs in airport hourly profile (both AH and FFCO2) and building spatial patterns (FFCO2 only) were fixed. Hourly emissions are reprocessed for all years to reflect those changes.

54 ENVIRONMENTAL SCIENCES↗

Materials Data on Na3H5(CO2)4 by Materials Project

Na3H5(CO2)4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing NaO6 octahedra. The corner-sharing octahedra tilt angles range from 72–78°. There are a spread of Na–O bond distances ranging from 2.40–2.55 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing NaO6 octahedra. The corner-sharing octahedra tilt angles range from 72–78°. There are a spread of Na–O bond distances ranging from 2.39–2.53 Å. There are two inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.11 Å. There is one shorter (1.25 Å) and one longer (1.29 Å) C–O bond length. In the second C2+ site, C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.12 Å. There is one shorter (1.26 Å) and one longer (1.27 Å) C–O bond length. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C2+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C2+ atom. In the third H1+ site, H1+ is bonded in a linear geometry to two equivalent O2- atoms. Both H–O bond lengths are 1.22 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to three Na1+ and one C2+ atom to form distorted corner-sharing ONa3C tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Na1+ and one C2+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one C2+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Na1+, one C2+, and one H1+ atom.

36 MATERIALS SCIENCE↗

Materials Data on KH3(CO2)2 by Materials Project

KH3(CO2)2 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.83–3.14 Å. There are two inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.11 Å. There is one shorter (1.24 Å) and one longer (1.30 Å) C–O bond length. In the second C2+ site, C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.11 Å. There is one shorter (1.25 Å) and one longer (1.29 Å) C–O bond length. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.14 Å) and one longer (1.30 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C2+ atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C2+ atom. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to four equivalent K1+ and one C2+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one C2+, and one H1+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent K1+ and one C2+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one C2+ and one H1+ atom.

36 MATERIALS SCIENCE↗

Materials Data on CuH6(CO2)4 by Materials Project

CuH6(CO2)4 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Cu2+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Cu–O bond distances ranging from 1.97–2.52 Å. There are two inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.10 Å. There is one shorter (1.23 Å) and one longer (1.33 Å) C–O bond length. In the second C2+ site, C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.10 Å. There is one shorter (1.27 Å) and one longer (1.28 Å) C–O bond length. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C2+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C2+ atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.73 Å) H–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Cu2+ and one C2+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu2+ and one C2+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one C2+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Cu2+, one C2+, and one H1+ atom.

36 MATERIALS SCIENCE↗

Materials Data on CO2 by Materials Project

CO2 is Cyanogen Chloride-derived structured and crystallizes in the tetragonal P4_12_12 space group. The structure is zero-dimensional and consists of four carbon dioxide molecules. C4+ is bonded in a linear geometry to two equivalent O2- atoms. Both C–O bond lengths are 1.17 Å. O2- is bonded in a single-bond geometry to one C4+ atom.

36 MATERIALS SCIENCE↗

Materials Data on CaH2(CO2)2 by Materials Project

CaH2(CO2)2 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Ca2+ is bonded to seven O2- atoms to form distorted edge-sharing CaO7 pentagonal bipyramids. There are a spread of Ca–O bond distances ranging from 2.34–2.58 Å. There are two inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.11 Å. Both C–O bond lengths are 1.27 Å. In the second C2+ site, C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.11 Å. There is one shorter (1.26 Å) and one longer (1.28 Å) C–O bond length. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C2+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C2+ atom. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ca2+ and one C2+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ca2+ and one C2+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ca2+ and one C2+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and one C2+ atom.

36 MATERIALS SCIENCE↗

Materials Data on RbH3(CO2)2 by Materials Project

RbH3(CO2)2 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Rb1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Rb–O bond distances ranging from 2.96–3.22 Å. There are two inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.11 Å. There is one shorter (1.24 Å) and one longer (1.30 Å) C–O bond length. In the second C2+ site, C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.11 Å. There is one shorter (1.25 Å) and one longer (1.29 Å) C–O bond length. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.15 Å) and one longer (1.30 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C2+ atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C2+ atom. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one Rb1+, one C2+, and one H1+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to four equivalent Rb1+ and one C2+ atom. In the third O2- site, O2- is bonded in a water-like geometry to one C2+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Rb1+ and one C2+ atom.

36 MATERIALS SCIENCE↗

Materials Data on SmH3(CO2)3 by Materials Project

SmH3(CO2)3 crystallizes in the trigonal R3m space group. The structure is three-dimensional. Sm3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sm–O bond distances ranging from 2.44–2.59 Å. C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.10 Å. There is one shorter (1.27 Å) and one longer (1.28 Å) C–O bond length. H1+ is bonded in a single-bond geometry to one C2+ atom. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sm3+ and one C2+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Sm3+ and one C2+ atom.

36 MATERIALS SCIENCE↗

Materials Data on Co2(GeS)3 by Materials Project

Co2(GeS)3 is Hausmannite-derived structured and crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are four inequivalent Co sites. In the first Co site, Co is bonded to three equivalent Ge and three equivalent S atoms to form CoGe3S3 octahedra that share corners with six equivalent CoGe3S3 octahedra, corners with six GeCo2S2 tetrahedra, and corners with six SCo2Ge2 tetrahedra. The corner-sharing octahedra tilt angles range from 54–59°. All Co–Ge bond lengths are 2.33 Å. All Co–S bond lengths are 2.24 Å. In the second Co site, Co is bonded to three equivalent Ge and three equivalent S atoms to form CoGe3S3 octahedra that share corners with six equivalent CoGe3S3 octahedra, corners with six GeCo2S2 tetrahedra, and corners with six SCo2Ge2 tetrahedra. The corner-sharing octahedra tilt angles range from 54–58°. All Co–Ge bond lengths are 2.33 Å. All Co–S bond lengths are 2.24 Å. In the third Co site, Co is bonded to three Ge and three S atoms to form CoGe3S3 octahedra that share corners with six CoGe3S3 octahedra, corners with six GeCo2S2 tetrahedra, and corners with six SCo2Ge2 tetrahedra. The corner-sharing octahedra tilt angles range from 54–59°. There are two shorter (2.32 Å) and one longer (2.34 Å) Co–Ge bond lengths. There are a spread of Co–S bond distances ranging from 2.24–2.27 Å. In the fourth Co site, Co is bonded to three Ge and three S atoms to form CoGe3S3 octahedra that share corners with six CoGe3S3 octahedra, corners with six GeCo2S2 tetrahedra, and corners with six SCo2Ge2 tetrahedra. The corner-sharing octahedra tilt angles range from 54–59°. There are two shorter (2.32 Å) and one longer (2.34 Å) Co–Ge bond lengths. There are one shorter (2.24 Å) and two longer (2.26 Å) Co–S bond lengths. There are four inequivalent Ge sites. In the first Ge site, Ge is bonded to two Co and two S atoms to form distorted GeCo2S2 tetrahedra that share corners with four CoGe3S3 octahedra, corners with four GeCo2S2 tetrahedra, corners with six SCo2Ge2 tetrahedra, and an edgeedge with one GeCo2S2 tetrahedra. The corner-sharing octahedra tilt angles range from 68–71°. There are one shorter (2.42 Å) and one longer (2.58 Å) Ge–S bond lengths. In the second Ge site, Ge is bonded to two Co and two S atoms to form distorted GeCo2S2 tetrahedra that share corners with four CoGe3S3 octahedra, corners with four GeCo2S2 tetrahedra, corners with six SCo2Ge2 tetrahedra, and an edgeedge with one GeCo2S2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–73°. There are one shorter (2.41 Å) and one longer (2.58 Å) Ge–S bond lengths. In the third Ge site, Ge is bonded to two Co and two S atoms to form distorted GeCo2S2 tetrahedra that share corners with four CoGe3S3 octahedra, corners with four GeCo2S2 tetrahedra, corners with six SCo2Ge2 tetrahedra, and an edgeedge with one GeCo2S2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–73°. There are one shorter (2.42 Å) and one longer (2.58 Å) Ge–S bond lengths. In the fourth Ge site, Ge is bonded to two Co and two S atoms to form distorted GeCo2S2 tetrahedra that share corners with four CoGe3S3 octahedra, corners with four GeCo2S2 tetrahedra, corners with six SCo2Ge2 tetrahedra, and an edgeedge with one GeCo2S2 tetrahedra. The corner-sharing octahedra tilt angles range from 68–72°. There are one shorter (2.42 Å) and one longer (2.60 Å) Ge–S bond lengths. There are four inequivalent S sites. In the first S site, S is bonded to two Co and two Ge atoms to form distorted SCo2Ge2 tetrahedra that share corners with four CoGe3S3 octahedra, corners with four SCo2Ge2 tetrahedra, corners with six GeCo2S2 tetrahedra, and an edgeedge with one SCo2Ge2 tetrahedra. The corner-sharing octahedra tilt angles range from 68–75°. In the second S site, S is bonded to two Co and two Ge atoms to form distorted SCo2Ge2 tetrahedra that share corners with four CoGe3S3 octahedra, corners with four SCo2Ge2 tetrahedra, corners with six GeCo2S2 tetrahedra, and an edgeedge with one SCo2Ge2 tetrahedra. The corner-sharing octahedra tilt angles range from 68–75°. In the third S site, S is bonded to two Co and two Ge atoms to form distorted SCo2Ge2 tetrahedra that share corners with four CoGe3S3 octahedra, corners with four SCo2Ge2 tetrahedra, corners with six GeCo2S2 tetrahedra, and an edgeedge with one SCo2Ge2 tetrahedra. The corner-sharing octahedra tilt angles range from 67–73°. In the fourth S site, S is bonded to two Co and two Ge atoms to form distorted SCo2Ge2 tetrahedra that share corners with four CoGe3S3 octahedra, corners with four SCo2Ge2 tetrahedra, corners with six GeCo2S2 tetrahedra, and an edgeedge with one SCo2Ge2 tetrahedra. The corner-sharing octahedra tilt angles range from 67–73°.

36 MATERIALS SCIENCE↗

Materials Data on Co2(GeTe)3 by Materials Project

Co2(GeTe)3 is Skutterudite-derived structured and crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are two inequivalent Co sites. In the first Co site, Co is bonded to three equivalent Ge and three equivalent Te atoms to form corner-sharing CoGe3Te3 octahedra. The corner-sharing octahedra tilt angles range from 47–58°. All Co–Ge bond lengths are 2.38 Å. All Co–Te bond lengths are 2.52 Å. In the second Co site, Co is bonded to three Ge and three Te atoms to form corner-sharing CoGe3Te3 octahedra. The corner-sharing octahedra tilt angles range from 46–58°. There are a spread of Co–Ge bond distances ranging from 2.35–2.37 Å. There are two shorter (2.54 Å) and one longer (2.56 Å) Co–Te bond lengths. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 4-coordinate geometry to two Co and two equivalent Te atoms. There are one shorter (2.78 Å) and one longer (2.96 Å) Ge–Te bond lengths. In the second Ge site, Ge is bonded in a 4-coordinate geometry to two equivalent Co and two equivalent Te atoms. There are one shorter (2.79 Å) and one longer (2.96 Å) Ge–Te bond lengths. There are two inequivalent Te sites. In the first Te site, Te is bonded in a 4-coordinate geometry to two Co and two equivalent Ge atoms. In the second Te site, Te is bonded in a 4-coordinate geometry to two equivalent Co and two equivalent Ge atoms.

36 MATERIALS SCIENCE↗