A simple method for the production of highly ordered porous carbon materials with increased hydrogen uptake capacities

Abstract

The synthesis, characterization and hydrogen uptake of porous carbons generated by heat treatment was investigated using various zeolites and mesoporous silicas as hard templates. The effect of heat treatment on the structural order, textural properties and hydrogen uptake capacities of porous carbons templated from the model zeolite EMC-2 in a temperature range of 600–800 °C during chemical vapour deposition were studied in details. The heat treatment improved the structural order of replicated microporous carbons, significantly increased both total and microporous surface area and pore volume, and remarkably increased the hydrogen uptake capacity. The optimized heat treatment conditions were at 900 °C for 3 h. The heat treatment at high temperatures was found to be a simple and general approach to synthesize well-ordered microporous carbons from different zeolite templates, using various carbon precursors and through different synthesis methods. The microporous carbons possessed a high surface area and pore volume with increased microporosity and therefore exhibited improved hydrogen storage capacities up to 5.85 wt% at 20 bar and −196 °C. The heat treatment, however, has no obvious effect on the textural properties and hydrogen uptake capacities for mesoporous carbons templated from mesoporous silicas.