Shaped nanoporous bodies

Abstract

A range of carbon materials can be produced using lignin in combination with synthetic phenolic resins or naturally occurring lingo-cellulosic materials. The lignin, which is essentially a naturally occurring phenolic resin, has a carbon yield on pyrolysis similar to that of the synthetic resins, which aids processing. The lignin can be used as a binder phase for synthetic resin or lignocellulosic materials allowing the production of monolithic carbons from a wide range of precursors, as the primary structural material where the thermal processing is modified by the addition of small quantities of synthetic resin materials or as structure modified in the production of meso/macro porous carbons in either bead, granular or monolithic form. A carbonised monolith is provided comprising mesoporous and/or macroporous carbon particles dispersed in a matrix of microporous carbon particles with voids between the particles defining paths for fluid to flow into and through the structure. The monolith may take the form of a shaped body having walls defining a multiplicity of internal transport channels for fluid flow, the transport channels being directed along the extrusion direction. The monolith may be made by carbonising a shaped phenolic body based on phenolic resin precursors. In a method for producing such a carbonisable shaped resin body solid particles of a first phenolic resin are provided which is partially cured so that the particles are sinterable but do not melt on carbonisation. The particles of the first phenolic resin are mixed with particles of a second phenolic resin that has a greater degree of cure than said first phenolic resin and has a mesoporous and/or macroporous microstructure that is preserved on carbonisation. The resulting mixture is formed into a dough e.g. by mixing the resin particles with methyl cellulose, PEO and water, after which the dough is extruded to form a shaped product and stabilising in its shape by sintering.