Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Mn-Ti”

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.

4 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Basal Plane Hydrogen Evolution Activity from Mixed Metal Nitride MXenes Measured by Scanning Electrochemical Microscopy

2D early transition metal carbide and nitride MXenes have intriguing properties for electrochemical energy storage and electrocatalysis. These properties can be manipulated by modifying the basal plane chemistry. Here, mixed transition metal nitride MXenes, M-Ti 4 N 3 T x (M = V, Cr, Mo, or Mn; T x = O and/or OH), are developed by modifying pristine exfoliated Ti 4 N 3 T x MXene with V, Cr, Mo, and Mn salts using a simple solution-based method. The resulting mixed transition metal nitride MXenes contain 6–51% metal loading (cf. Ti) that exhibit rich electrochemistry including highly tunable hydrogen evolution reaction (HER) electrocatalytic activity in a 0.5 m H 2 SO 4 electrolyte as follows: V-Ti 4 N 3 T x > Cr-Ti 4 N 3 T x > Mo-Ti 4 N 3 T x > Mn-Ti 4 N 3 T x > pristine Ti 4 N 3 T x with overpotentials as low as 330 mV at -10 mA cm -2 with a charge-transfer resistance of 70 O. Scanning electrochemical microscopy (SECM) reveals the electrochemical activity of individual MXene flakes. The SECM data corroborate the bulk HER activity trend for M-Ti 4 N 3 T x as well as provide the first experimental evidence that HER results from catalysis on the MXene basal plane. These electrocatalytic results demonstrate a new pathway to tune the electrochemical properties of MXenes for water splitting and related electrochemical applications.

2D materials↗
DOE OSTI2020

Materials Data on TiMn2 by Materials Project

TiMn2 is Hexagonal Laves structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ti is bonded in a 12-coordinate geometry to four equivalent Ti and twelve Mn atoms. There are three shorter (2.91 Å) and one longer (2.92 Å) Ti–Ti bond lengths. All Ti–Mn bond lengths are 2.78 Å. There are two inequivalent Mn sites. In the first Mn site, Mn is bonded to six equivalent Ti and six equivalent Mn atoms to form a mixture of edge, face, and corner-sharing MnTi6Mn6 cuboctahedra. All Mn–Mn bond lengths are 2.41 Å. In the second Mn site, Mn is bonded to six equivalent Ti and six Mn atoms to form a mixture of edge, face, and corner-sharing MnTi6Mn6 cuboctahedra. There are two shorter (2.29 Å) and two longer (2.45 Å) Mn–Mn bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti21Mn25 by Materials Project

Ti21Mn25 is Frank-Kasper $\mu$ Phase-like structured and crystallizes in the trigonal R-3c space group. The structure is three-dimensional. there are four inequivalent Ti sites. In the first Ti site, Ti is bonded in a 12-coordinate geometry to eight Ti and four Mn atoms. There are a spread of Ti–Ti bond distances ranging from 2.85–2.93 Å. There are two shorter (2.62 Å) and two longer (2.67 Å) Ti–Mn bond lengths. In the second Ti site, Ti is bonded in a 12-coordinate geometry to seven Ti and seven Mn atoms. There are a spread of Ti–Ti bond distances ranging from 2.78–3.22 Å. There are a spread of Ti–Mn bond distances ranging from 2.64–2.78 Å. In the third Ti site, Ti is bonded in a 12-coordinate geometry to four Ti and twelve Mn atoms. There are two shorter (2.87 Å) and one longer (2.91 Å) Ti–Ti bond lengths. There are a spread of Ti–Mn bond distances ranging from 2.73–2.88 Å. In the fourth Ti site, Ti is bonded in a 12-coordinate geometry to six Ti and eight Mn atoms. There are one shorter (2.67 Å) and one longer (2.79 Å) Ti–Ti bond lengths. There are a spread of Ti–Mn bond distances ranging from 2.65–2.94 Å. There are six inequivalent Mn sites. In the first Mn site, Mn is bonded to six equivalent Ti and six Mn atoms to form MnTi6Mn6 cuboctahedra that share corners with twelve MnTi6Mn6 cuboctahedra, edges with four equivalent MnTi7Mn5 cuboctahedra, and faces with sixteen MnTi6Mn6 cuboctahedra. There are a spread of Mn–Mn bond distances ranging from 2.34–2.47 Å. In the second Mn site, Mn is bonded to seven Ti and five Mn atoms to form a mixture of edge, face, and corner-sharing MnTi7Mn5 cuboctahedra. There are a spread of Mn–Mn bond distances ranging from 2.39–2.44 Å. In the third Mn site, Mn is bonded to eight Ti and four Mn atoms to form MnTi8Mn4 cuboctahedra that share corners with eight MnTi7Mn5 cuboctahedra, edges with two equivalent MnTi8Mn4 cuboctahedra, and faces with eight MnTi7Mn5 cuboctahedra. Both Mn–Mn bond lengths are 2.42 Å. In the fourth Mn site, Mn is bonded to seven Ti and five Mn atoms to form distorted MnTi7Mn5 cuboctahedra that share corners with eleven MnTi6Mn6 cuboctahedra, edges with three MnTi7Mn5 cuboctahedra, and faces with thirteen MnTi6Mn6 cuboctahedra. Both Mn–Mn bond lengths are 2.35 Å. In the fifth Mn site, Mn is bonded in a 12-coordinate geometry to seven Ti and five Mn atoms. The Mn–Mn bond length is 2.37 Å. In the sixth Mn site, Mn is bonded to six equivalent Ti and six equivalent Mn atoms to form MnTi6Mn6 cuboctahedra that share edges with six equivalent MnTi7Mn5 cuboctahedra and faces with twenty MnTi6Mn6 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti5Mn7 by Materials Project

Ti5Mn7 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. there are three inequivalent Ti sites. In the first Ti site, Ti is bonded in a 12-coordinate geometry to seven Ti and nine equivalent Mn atoms. There are a spread of Ti–Ti bond distances ranging from 2.83–2.99 Å. There are six shorter (2.82 Å) and three longer (2.91 Å) Ti–Mn bond lengths. In the second Ti site, Ti is bonded in a 12-coordinate geometry to four Ti and twelve Mn atoms. All Ti–Ti bond lengths are 2.93 Å. There are three shorter (2.74 Å) and nine longer (2.81 Å) Ti–Mn bond lengths. In the third Ti site, Ti is bonded to six equivalent Ti and six equivalent Mn atoms to form TiTi6Mn6 cuboctahedra that share corners with twelve equivalent MnTi7Mn5 cuboctahedra, edges with six equivalent TiTi6Mn6 cuboctahedra, and faces with twenty MnTi6Mn6 cuboctahedra. All Ti–Mn bond lengths are 2.49 Å. There are two inequivalent Mn sites. In the first Mn site, Mn is bonded to seven Ti and five Mn atoms to form distorted MnTi7Mn5 cuboctahedra that share corners with two equivalent TiTi6Mn6 cuboctahedra, corners with sixteen MnTi7Mn5 cuboctahedra, edges with six equivalent MnTi7Mn5 cuboctahedra, faces with three equivalent TiTi6Mn6 cuboctahedra, and faces with fifteen MnTi7Mn5 cuboctahedra. There are a spread of Mn–Mn bond distances ranging from 2.31–2.50 Å. In the second Mn site, Mn is bonded to six equivalent Ti and six equivalent Mn atoms to form MnTi6Mn6 cuboctahedra that share corners with twelve equivalent MnTi7Mn5 cuboctahedra, edges with six equivalent MnTi6Mn6 cuboctahedra, faces with two equivalent TiTi6Mn6 cuboctahedra, and faces with eighteen equivalent MnTi7Mn5 cuboctahedra.

36 MATERIALS SCIENCE↗