- Award ID(s):
- Publication Date:
- NSF-PAR ID:
- Journal Name:
- Dalton Trans.
- Page Range or eLocation-ID:
- 11233 to 11242
- Sponsoring Org:
- National Science Foundation
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In this study, we present experimental and theoretical results on dissociative electron attachment and dissociative ionisation for the potential FEBID precursor cis -Pt(CO) 2 Cl 2 . UHV surface studies have shown that high purity platinum deposits can be obtained from cis -Pt(CO) 2 Cl 2 . The efficiency and energetics of ligand removal through these processes are discussed and experimental appearance energies are compared to calculated thermochemical thresholds. The present results demonstrate the potential effectiveness of electron-induced reactions in the deposition of this FEBID precursor, and these are discussed in conjunction with surface science studies on this precursor and the design of new FEBID precursors.
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Experimental and Computational Studies of Compression and Deformation Behavior of Hafnium Diboride to 208 GPaThe compression behavior of the hexagonal AlB2 phase of Hafnium Diboride (HfB2) was studied in a diamond anvil cell to a pressure of 208 GPa by axial X-ray diffraction employing platinum as an internal pressure standard. The deformation behavior of HfB2 was studied by radial X-ray diffraction technique to 50 GPa, which allows for measurement of maximum differential stress or compressive yield strength at high pressures. The hydrostatic compression curve deduced from radial X-ray diffraction measurements yielded an ambient-pressure volume V0 = 29.73 Å3/atom and a bulk modulus K0 = 282 GPa. Density functional theory calculations showed ambient-pressure volume V0 = 29.84 Å3/atom and bulk modulus K0 = 262 GPa, which are in good agreement with the hydrostatic experimental values. The measured compressive yield strength approaches 3% of the shear modulus at a pressure of 50 GPa. The theoretical strain-stress calculation shows a maximum shear stress τmax~39 GPa along the (1−10)  direction of the hexagonal lattice of HfB2, which thereby can be an incompressible high strength material for extreme-environment applications.
Tandem In 2 O 3 -Pt/Al 2 O 3 catalyst for coupling of propane dehydrogenation to selective H 2 combustion
Tandem catalysis couples multiple reactions and promises to improve chemical processing, but precise spatiotemporal control over reactive intermediates remains elusive. We used atomic layer deposition to grow In2O3over Pt/Al2O3, and this nanostructure kinetically couples the domains through surface hydrogen atom transfer, resulting in propane dehydrogenation (PDH) to propylene by platinum, then selective hydrogen combustion by In2O3, without excessive hydrocarbon combustion. Other nanostructures, including platinum on In2O3or platinum mixed with In2O3, favor propane combustion because they cannot organize the reactions sequentially. The net effect is rapid and stable oxidative dehydrogenation of propane at high per-pass yields exceeding the PDH equilibrium. Tandem catalysis using this nanoscale overcoating geometry is validated as an opportunity for highly selective catalytic performance in a grand challenge reaction.
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