Hydrogen transfer pathways under restricted diffusion

Conference · Wed Jan 01 00:00:00 EST 1992

OSTI ID:5925952

Buchanan, III, A C; Britt, P F

The impact of restricted mass transport on the thermal processing of coal is being explored through the study of organic model compounds that are covalently anchored to an inert silica surface. Two-component surfaces are being prepared and pyrolyzed at 375{degrees}C that contain a thermally reactive component (Ph(CH{sub 2}){sub n}Ph, n=2--4) in the presence of a second component that is either thermally inert (biphenyl or naphthalene) or contains reactive C-H bonds (diphenylmethane (DPM) or 9,10-dihydrophenanthrene (DHP)). Reactions are found to be highly sensitive to the spatial distribution of hydrogen donors and nondonors that surround immobilized free-radical intermediates. In the presence of DPM or DHP, rapid serial hydrogen transfer steps allow radical intermediates to migrate across the surface overcoming normal diffusional limitations. Studies with DHP also reveal a minor reaction channel in which strong bond cleavage reactions occur via hydrogen transfer in these diffusionally constrained environments.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5925952
• Report Number(s): CONF-920444-10; ON: DE92007250
• Resource Relation: Conference: American Chemical Society national meeting, San Francisco, CA (United States), 5-10 Apr 1992
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
01 COAL, LIGNITE, AND PEAT
ALKYLATED AROMATICS
PYROLYSIS
CROSS-LINKING
HYDROGEN TRANSFER
RADICALS
REACTION INTERMEDIATES
SILICA
TEMPERATURE RANGE 0400-1000 K
AROMATICS
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
MINERALS
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
POLYMERIZATION
SILICON COMPOUNDS
SILICON OXIDES
TEMPERATURE RANGE
THERMOCHEMICAL PROCESSES
400201* - Chemical & Physicochemical Properties
400800 - Combustion
Pyrolysis
& High-Temperature Chemistry
010409 - Coal
Lignite
& Peat- Pyrolysis & Carbonization- (1987-)