Non-oxidative dehydrogenation of propane to propene over Pt-Sn/Al[subscript 2]O[subscript 3] catalys
Explore the source record for details and available documents.
Gao, Xiaofeng↗
SEARCH · Engineering Papers
Results for “Pt-Sn”
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.
Selective Catalytic Behavior Induced by Crystal–Phase Transformation in Well–Defined Bimetallic Pt–Sn Nanocrystals
The Pt-Sn bimetallic system is a much studied and commercially used catalyst for propane dehydrogenation. The traditionally prepared catalyst, however, suffers from inhomogeneity and phase separation of the active Pt–Sn phase. Colloidal chemistry offers a route for the synthesis of Pt–Sn bimetallic nanoparticles (NPs) in a systematic, well-defined, tailored fashion over conventional methods. Here, the successful synthesis of well-defined ≈2 nm Pt, PtSn, and Pt 3 Sn nanocrystals with distinct crystallographic phases is reported; hexagonal close packing (hcp) PtSn and fcc Pt 3 Sn show different activity and stability depending on the hydrogen-rich or poor environment in the feed. Moreover, face centred cubic (fcc) Pt 3 Sn/Al 2 O 3 , which exhibited the highest stability compared to hcp PtSn, shows a unique phase transformation from an fcc phase to an L1 2 -ordered superlattice. Contrary to PtSn, H 2 cofeeding has no effect on the Pt 3 Sn deactivation rate. Finally, the results reveal structural dependency of the probe reaction, propane dehydrogenation, and provide a fundamental understanding of the structure–performance relationship on emerging bimetallic systems.
36 MATERIALS SCIENCE↗
Stable and selective catalysts for propane dehydrogenation operating at thermodynamic limit
Hitting the limits on propene synthesis The greater abundance of propane from shale gas has spurred efforts to use it as a propylene feedstock. Direct dehydrogenation catalysts consisting of platinum–tin alloy nanoparticles supported on alumina often must run with hydrogen dilution to avoid carbon buildup and excess tin to avoid alloy segregation. Motagamwala et al. report that platinum–tin nanoparticles interact more weakly with a silica support and the metals thus do not segregate. The use of undiluted reactants allowed the reaction to run near the thermodynamically limit of about 67% conversion with a selectivity to propylene of more than 99%. This catalyst also does not build up carbon and could run up to 30 hours without deactivation. Science , abg7894, this issue p. 217
Science & Technology - Other Topics↗
Materials Data on SnPt by Materials Project
PtSn crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Pt2- is bonded in a 6-coordinate geometry to two equivalent Pt2- and six equivalent Sn2+ atoms. Both Pt–Pt bond lengths are 2.76 Å. All Pt–Sn bond lengths are 2.78 Å. Sn2+ is bonded in a 6-coordinate geometry to six equivalent Pt2- atoms.
36 MATERIALS SCIENCE↗
Materials Data on Sn2Pt by Materials Project
PtSn2 is Fluorite structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Pt is bonded in a body-centered cubic geometry to eight equivalent Sn atoms. All Pt–Sn bond lengths are 2.84 Å. Sn is bonded to four equivalent Pt atoms to form a mixture of edge and corner-sharing SnPt4 tetrahedra.
36 MATERIALS SCIENCE↗
Materials Data on Sn4Pt by Materials Project
PtSn4 crystallizes in the orthorhombic Ccce space group. The structure is two-dimensional and consists of two PtSn4 sheets oriented in the (0, 1, 0) direction. Pt is bonded in a 8-coordinate geometry to eight equivalent Sn atoms. There are four shorter (2.83 Å) and four longer (2.84 Å) Pt–Sn bond lengths. Sn is bonded in a 2-coordinate geometry to two equivalent Pt atoms.
36 MATERIALS SCIENCE↗
Materials Data on SnPt3 by Materials Project
Pt3Sn is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pt+0.67- is bonded to eight equivalent Pt+0.67- and four equivalent Sn2+ atoms to form PtSn4Pt8 cuboctahedra that share corners with twelve equivalent PtSn4Pt8 cuboctahedra, edges with eight equivalent SnPt12 cuboctahedra, edges with sixteen equivalent PtSn4Pt8 cuboctahedra, faces with four equivalent SnPt12 cuboctahedra, and faces with fourteen equivalent PtSn4Pt8 cuboctahedra. All Pt–Pt bond lengths are 2.87 Å. All Pt–Sn bond lengths are 2.87 Å. Sn2+ is bonded to twelve equivalent Pt+0.67- atoms to form SnPt12 cuboctahedra that share corners with twelve equivalent SnPt12 cuboctahedra, edges with twenty-four equivalent PtSn4Pt8 cuboctahedra, faces with six equivalent SnPt12 cuboctahedra, and faces with twelve equivalent PtSn4Pt8 cuboctahedra.
36 MATERIALS SCIENCE↗
Materials Data on Sn3Pt2 by Materials Project
Pt2Sn3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Pt is bonded in a distorted body-centered cubic geometry to one Pt and seven Sn atoms. The Pt–Pt bond length is 2.82 Å. There are a spread of Pt–Sn bond distances ranging from 2.72–2.91 Å. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded to four equivalent Pt atoms to form a mixture of distorted edge and corner-sharing SnPt4 tetrahedra. In the second Sn site, Sn is bonded in a 6-coordinate geometry to six equivalent Pt atoms.
36 MATERIALS SCIENCE↗