PHENOLIC-RESIN-DERIVED ACTIVATED CARBONS

A novel binderless preparative route is described for the production o f phenolic-resin-derived carbons for use as catalyst supports and adso rbents. The carbons can be produced in a wide variety of physical form s ranging from simple granules to large monolithic structures. The ful ly interconnected macropore structure of the carbons, which derives fr om the interconnected voids between the primary resin particles, can b e precisely controlled to give a mean macropore size of between around 1 and 50 microns. This then gives rise to very high permeabilities th at can be orders of magnitude higher than conventional porous support materials. The microstructure of the carbons appears to derive from th e void spaces between small (similar to 4 nm) spherical resin domains generated during the initial polymer curing step which gives rise to a very narrow pore distribution with a mean pore size of approximate to 0.8 nm. This is in contrast to earlier studies that suggested the por es reflected voids in a tangled ribbon structure. The high purity of t he carbons (total metals content of <500 ppm) has also allowed a preci se determination of the activation kinetics. This has shown that the a s-produced carbon comprises two domains - a low reactivity skeleton fo rmed from the small resin domains, and a higher reactivity carbon that appears to partially fill the skeletal pore structure and that is sel ectively removed during activation. (C) 1998 Elsevier Science B.V. All rights reserved.