II International Symposium on Carbon for Catalysis ABSTRACTS

PREPARATION OF CARBON FILMS ON CERAMIC SUPPORTS
PL-2
Tennison S.
MAST Carbon Technology Ltd., Henley Park, England
e-mail: Steve.tennison@mastcarbon.co.uk
Introduction
Polymer derived nanoporous carbons offer many advantages over carbons based on
naturally occurring carbon as catalyst supports. These include precisely controlled pore
structure 1,2 , greatly enhanced reproducibility, high purity and the ability to precisely control
the surface chemistry 3 . In some cases the possibility also exists to produce the materials in a
wide range of physical forms to suit different applications. MAST has spent several years,
through a variety of collaborative projects 4,5 and in house research, developing a family of
phenolic resin derived that can be produced in physical forms from extrudates and beads,
through complex monolithic structures to asymmetric membranes. In the latter case these
membranes can either be pure carbon systems or carbon coated ceramics. One of the major
benefits of the phenolic system is that all of these physical forms exhibit a common pore and
surface structure and therefore similar characteristics when used as catalyst supports. This
presentation will therefore first review the pore, surface chemistry and catalyst characteristics
of the phenolic resin derived carbons and subsequently the production, structure and
performance the carbon-ceramic composite membrane devices based on phenolic resin.
Phenolic Resin Derived Carbons
The pore structure of the phenolic based carbons derives directly from the underlying
polymer structure and is similar for all phenolic precursors. The production of the crosslinked
resin from the novolak or resol precursors gives rise to a phase separation process within the
polymer matrix during crosslinking that leads to the formation of microdomains of highly
crosslinked resin a matrix of less cured resin. Pyrolysis then leads to the loss of the less
crosslinked material leaving a matrix of interlinked, high density nanobeads of 5-10nm
diameter where the resulting pore structure comprises the voids between these beads. It is this
process that give the phenolic derived carbons their unique structure. This phase separation
process also underpins the production of the mesoporous carbons via a secondary phase
separation process.
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