Search NASA⌕ Search

SEARCH · Search NASA

Results for “N-Ru”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

8 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

LaCeO x coupled N-doped graphene/Ru single-atoms as a binary-site catalyst for efficient hydrogen evolution based on hydrogen spillover

Based on the hydrogen spillover effect, versatile binary-site catalysts are promising for the alkaline hydrogen evolution reaction (HER). In which one site can adsorb and dissociate water, while the neighboring site is favorable for liberating hydrogen. Inspired by these possibilities, oxygen vacancy (O v )-rich LaCeO x coupled N-doped graphene/Ru single-atoms (LaCeO x @NGr/Ru 1 ) was synthesized as an efficient dual-site HER catalyst. It delivered an impressive low overpotential of 22 mV at a current density of 10mAcm –2 and a slight Tafel slope of 40 mV dec –1 in an alkaline medium, outstanding the advanced Ru-based catalysts. Moreover, this promising binary-component catalyst exhibited higher mass activity and longer lasting durability than commercial Pt/C catalyst (20 wt%). Finally, experimental and theoretical investigations provided insights into the HER mechanisms of LaCeO x @NGr/Ru 1 based on three indispensable steps: water adsorption and dissociation on O v -rich LaCeO x , diffusion of generated H* species towards Ce 3+ -N-Ru 1 bridges, and hydrogen evolution on Ru 1 sites.

36 MATERIALS SCIENCE↗
DOE OSTI2026

The presence of Ru metal modifies the behavior of deuterium bound to pyridinic nitrogen in doped graphene-like materials

We used a combination of x-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) to investigate how the presence of a ruthenium (Ru) metal substrate modifies the N-D bond strength of the pyridinic nitrogen species in nitrogen (N)-doped graphene (Gr) on Ru(0001) compared to metal-free highly-oriented pyrolytic graphite (HOPG) substrate. The N-dopants were introduced through low-energy N+/N2+ irradiation. N is embedded in the carbon materials in two predominant configurations: as graphitic N (GN: N substituted in the hexagonal C lattice) and pyridinic N (PN: substitutional N adjacent to a C vacancy). XPS data showed that upon atomic deuterium (D) exposure at 220 K, the PN peak shifted to a higher binding energy by +1.2 eV for HOPG and +1.0 eV for N-doped graphene on Ru(0001), while the GN peak remained unchanged, indicating that the D atoms bound solely to pyridinic N. 85% of PN sites on HOPG can be saturated with D atoms, whereas only ~30% of pyridinic N sites are able to bind D atoms in N-doped Gr/Ru(0001). Our DFT analysis shows that this difference is due to the coordination of PN to Ru atoms, which necessitates bond cleavage of the N-Ru interaction prior to D atom adsorption. D begins desorbing from N-HOPG at ~573 K and is fully desorbed by ~973 K, whereas desorption from N-doped graphene on Ru(0001) begins at ~290 K, with complete desorption observed at ~700 K, indicating that the Ru metal weakens the N-D bond strength. We also studied a high-surface-area, layered, and porous N-doped carbon material, internally labeled NC900, which was synthesized by pyrolysis of glucose and graphitic carbon nitride (g-C3N4) at 1173 K. D exposure caused a +1.1 eV PN peak shift in NC900, with no change in the GN peak. Moreover, the NC900 exhibited the same desorption behavior as HOPG, demonstrating that well-defined model systems can effectively capture the behavior of more complex N-doped carbon materials.

Alupothe Gedara, Buddhika S.↗
DOE OSTI2020

Materials Data on RuN by Materials Project

RuN is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Ru3+ is bonded to six equivalent N3- atoms to form a mixture of distorted face, edge, and corner-sharing RuN6 pentagonal pyramids. All Ru–N bond lengths are 2.18 Å. N3- is bonded to six equivalent Ru3+ atoms to form a mixture of distorted face, edge, and corner-sharing NRu6 pentagonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RuN2 by Materials Project

RuN2 is Marcasite structured and crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. Ru6+ is bonded to six equivalent N3- atoms to form RuN6 octahedra that share corners with eight equivalent RuN6 octahedra, corners with six equivalent NRu3N tetrahedra, and edges with two equivalent RuN6 octahedra. The corner-sharing octahedral tilt angles are 68°. There are two shorter (2.08 Å) and four longer (2.12 Å) Ru–N bond lengths. N3- is bonded to three equivalent Ru6+ and one N3- atom to form distorted NRu3N tetrahedra that share corners with three equivalent RuN6 octahedra, corners with thirteen equivalent NRu3N tetrahedra, and an edgeedge with one NRu3N tetrahedra. The corner-sharing octahedra tilt angles range from 62–66°. The N–N bond length is 1.34 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RuN by Materials Project

RuN is Molybdenum Carbide MAX Phase-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ru3+ is bonded to six equivalent N3- atoms to form a mixture of edge, face, and corner-sharing RuN6 octahedra. The corner-sharing octahedral tilt angles are 47°. All Ru–N bond lengths are 2.16 Å. N3- is bonded to six equivalent Ru3+ atoms to form a mixture of distorted edge and corner-sharing NRu6 pentagonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RuN by Materials Project

RuN is Halite, Rock Salt structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Ru3+ is bonded to six equivalent N3- atoms to form a mixture of edge and corner-sharing RuN6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ru–N bond lengths are 2.17 Å. N3- is bonded to six equivalent Ru3+ atoms to form a mixture of edge and corner-sharing NRu6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RuN by Materials Project

RuN is Zincblende, Sphalerite structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. Ru3+ is bonded to four equivalent N3- atoms to form corner-sharing RuN4 tetrahedra. All Ru–N bond lengths are 1.98 Å. N3- is bonded to four equivalent Ru3+ atoms to form corner-sharing NRu4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RuN2 by Materials Project

RuN2 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Ru6+ is bonded in a body-centered cubic geometry to eight equivalent N3- atoms. All Ru–N bond lengths are 2.25 Å. N3- is bonded in a 5-coordinate geometry to four equivalent Ru6+ and one N3- atom. The N–N bond length is 1.32 Å.

36 MATERIALS SCIENCE↗