Influence of chemical vapour infiltration conditions of acetylene on the structural and textural properties of EMT-type zeolite nanocasted carbon replica

Ordered microporous carbons were synthesized by the nanocasting process using EMC-2 zeolite (EMT structure type) and acetylene as a mould and a carbon precursor, respectively. In this study, the conditions of the synthesis methods for preparing the ordered microporous carbons were examined. Temperature and duration parameters for the chemical vapour infiltration were optimized to yield an ordered carbon replica that displays up the three XRD diffraction peaks. This faithful replica exhibits also a high micropore volume (1.3-1.4 cm(3)/g) with mainly supermicroporosity, a high specific surface area (> 2900 m(2)/g) and nearly no mesoporosity. The pore size distribution calculated with NLDFT method from nitrogen physisorption data shows three maxima at 0.6, 1.0 and 1.8 nm diameters. The second is due to the zeolite wall dissolution. The first and the third are attributed to different types of default. Compared to the classical two-step procedure, the direct infiltration with acetylene appears an interesting route for the preparation of ordered microporous carbon replicas with high micropore volume.