2.1.2. Nb2O5 Synthesis Supported on MCM-41 through the Incipient Humidity Impregnation Method (Nb/MC-41-ImpHum)

Impregnation was carried out using 10 mL of an aqueous solution of niobium oxalate in 0.1 M of oxalic acid with which 1.1034 g of the MCM-41 material were impregnated, drop by drop, until the whole solid was humid; the amount of niobium oxolate aggregated was 0.4756, 0.9512, and 1.4268 g to obtain niobium percentages of 10%, 20%, and 30%, respectively, in the mesoporous silica material. The humid solid was air dried at 60 °C and, thereafter, calcined at 550 °C for 6 h.
