Description
One of important application of Activated Carbon is as catalyst
Carrier and promoter, also can be directly as catalyst. As a
carrier, mainly used to carry catalyst, lets catalyst load on its
surface and makes it possess certain physical and chemical
property, carrier itself generally does not have catalytic
activity.
Activated carbon impregnated with metal salts solution can make the
catalyst load on the surface of activated carbon, activated carbons
surface oxidation, acidic functional groups, electron accepting
ability, free radicals, pore structure, chemical structure can
affect the performance of the active component.
Activated carbon has the irregular graphite structure, in which
includes traces of ash, nitrogen, sulfur, hydrogen, oxygen and so
on, these ingredients can have the influence to the catalyst
performance; Ash is an important indicator of support activated
carbon; C-O structure on the surface of activated carbon will
affect oxidizing reaction, halogenating response, adsorption
performance and electricity performance.
Due to activated carbon has abundant pore structure, special
electronic properties, easy to regulate surface groups, high
specific surface area, strong acid-resistant, alkali-resistant and
heat-resistant properties, when used as a catalyst carrier, the
precursor of active component is fully dispersed. Activated carbon
itself has catalytic activity, interaction with active component
can affect the activity and selectivity of the catalyst, and can
save the quantity of active substance. Compare with using metal
alone, when activated carbon carriers trace amounts of transition
metals, hydrogen shows obvious reversible adsorption phenomenon,
this called overflow spillover phenomenon.
Activated carbon includes powder and granule, in the process of
gas-solid reaction, all used granule activated carbon as catalyst
carrier. Although activated carbons specific surface area is very
high, but compare with activated alumina carrier, honeycomb
ceramics carrier and molecular sieve carrier, its mechanical
strength is lower. Therefore, in the production process, commonly
activated carbons strength is controlled above *5%.
Precious metal catalyst includes Pd catalyst, Ru catalyst, rhodium
catalyst, Pt catalyst, etc. As precious metal support, activated
carbon shape can be powder, cylinder, sphere and granule.
The application of activated carbon catalyst carrier:
(1) Isomerization: Ni-Carbon catalyst can let plant oil
isomerization (cottonseed oil, linseed oil, rapeseed oil, etc.),
from non-conjugated oil into conjugated forms;
(2) Hydrogenation, dehydrogenation and dehydrogenation of
aromatization, cyclization and isomerization: Pd-activated carbon
catalyst or Pt-activated carbon catalyst can play this catalytic
role;
(3) Low pressure polymerization of olefins: Activated carbon loads
on Ni, Co or their oxide can let olefin polymerization;
(4) Synthetic fibre: In the production of vinylon, activated carbon
impregnated zinc acetate can let acetylene and acetic acid
synthetise vinyl acetate;
(5) Gum Rosin reprocessing: Activated carbon loads on Pd can
produce hydrogenated rosin and disproportionated rosin;
(6) Synthesis of vinyl chloride: Activated carbon loads on mercuric
chloride can let acetylene and hydrogen chloride synthetise vinyl
chloride.
