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Title: High-Temperature-Stable and Regenerable Catalysts: Platinum Nanoparticles in Aligned Mesoporous Silica Wells

We report the synthesis, structural characterization, thermal stability study, and regeneration of nanostructured catalysts made of 2.9 nm Pt nanoparticles sandwiched between a 180nm SiO 2 core and a mesoporous SiO 2 shell. The SiO 2 shell consists of 2.5 nm channels that are aligned perpendicular to the surface of the SiO 2 core. The nanostructure mimics Pt nanoparticles that sit in mesoporous SiO 2 wells (Pt@MSWs). By using synchrotron-based small-angle X-ray scattering, we were able to prove the ordered structure of the aligned mesoporous shell. By using high-temperature cyclohexane dehydrogenation as a model reaction, we found that the Pt@MSWs of different well depths showed stable activity at 500°C after the induction period. Conversely, a control catalyst, SiO 2-sphere-supported Pt nanoparticles without a mesoporous SiO 2 shell (Pt/SiO 2), was deactivated. We deliberately deactivated the Pt@MSWs catalyst with a 50nm deep well by using carbon deposition induced by a low H2/cyclohexane ratio. The deactivated Pt@MSWs catalyst was regenerated by calcination at 500°C with 20% O 2 balanced with He. After the regeneration treatments, the activity of the Pt@MSWs catalyst was fully restored. Our results suggest that the nanostructured catalysts—Pt nanoparticles confined inside mesoporous SiO 2 wells—are stable and regenerable formore » treatments and reactions that require high temperatures.« less
Authors:
 [1] ;  [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [1]
  1. Ames Laboratory
  2. Argonne Laboratory
Publication Date:
OSTI Identifier:
1132273
Report Number(s):
IS-J 8187
Journal ID: ISSN 1864-564X
DOE Contract Number:
DE-AC02-07CH11358
Resource Type:
Journal Article
Resource Relation:
Journal Name: ChemSusChem (Online); Journal Volume: 6; Journal Issue: 10
Publisher:
ChemPubSoc Europe
Research Org:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; dehydrogenation; heterogeneous catalysis; mesoporous materials; nanoparticles; platinum