The reported catalysts showed excellent

The first, more rapid loss occurred between and 130 °C, which was attributed to loss of water and free moisture adsorbed on the catalyst surface. The second weight 'SAR191801' loss region occurred at 240–380 °C; 6–8% weight loss in prothallus region was attributed to the removal of SO3H groups, as this region was absent in the non-sulfonated materials. Following the 2nd region, weight loss continued but at a much slower rate which could be credited to the graphitization of AC ( Fig. 4).