III International Conference

PP-II-71The acidity, measured by two cycles adsorption of ammonia and temperatureprogrammeddesorption of NH 3, was the highest for MCF-et-ph-SO 3 H.Catalytic activity of materials was tested in esterification of butanol with acetic acid in astirred batch system at 348 K. The molar ratio of acetic acid:butanol was 1:1. Directly, beforeusing catalysts were dried at 473 K. The amount of catalyst used in the reaction was 1 wt%.Products of reaction were analyzed by a GC HP 5890 Series II with a TCD detector. GC and1 H NMR analysis confirmed that no by-products were formed.The highest conversions of acetic acid (ca. 70 %) after 6 h were obtained for samplesfunctionalized with -et-ph-SO 3 H groups (Fig. 1A), which is in accord with the measuredacidity. The catalyst can be used repeatedly without significant loss of the activity duringseveral catalytic cycles (Fig. 1B). We have found that the amount of the functional groups inthe range of 1 or 1.5 mmol/g has no affect on the catalytic activity of materials.Only a small decrease in surface area was observed after six catalytic cycles, while thevalues of pore volume and pore size were quite well preserved.Conversion [%]807060504030A23456Conversion [%]7060504030B12620101201000 50 100 150 200 250 300 350 400Time [min]00 50 100 150 200 250 300 350 400Time [min]Fig. 1. Conversion of acetic acid vs. time. A: 1 – without catalyst; 2 – H 2 SO 4 ; 3 – MCF-et-ph-SO 3 H; 4 – MCFph-SO3 H(a); 5 – MCF-ph-SO 3 H(b); 6 – MCF-propyl SO 3 H; sulfonation by chlorosulfonic acid (a), oleum (b).B: after 1, 2 and 6 catalytic cycles for MCF-et-ph-SO 3 H.295