157Sulfated Inorganic Oxides for Methyl Esters Production
off ratio from 0.3/0.7 on, the conversion does not increase much more if compared
to the one achieved with the sample obtained via traditional sol–gel synthesis. Their
conversions are in fact comparable (see samples USZ_40_0.3_30, USZ_40_0.5_30,
USZ_40_0.7_30, and SZT in Figure 6.8a). The similarity in the catalytic perfor-
mance of these catalysts may be ascribable to the fact that they are characterized
by comparable values of SSA (entries 2, 5, 8, 10 in Table 6.2), and in the case of the
catalysts obtained with pulses, also by comparable acidities (entries 5, 8, 10 in Table
6.2). A high SSA may in fact be disadvantageous for the catalysis of the reaction
here studied. FFA are high ...