Ultrasonic enhancement of the acidity, surface area and free fatty acids esterification catalytic activity of sulphated ZrO 2 –TiO 2 systems

Synthesis of Ti(SO 4 )O solid acid nano-catalyst and its application for biodiesel production from used cooking oil

“…Several synthetic routes were applied for the preparation of heterogeneous catalysts including sol-gel [24][25][26][27], solvent-free [28,29] and hydrothermal methods [30][31][32][33]. Examples of heterogeneous catalysts include SO /TiO2 [30,[34][35][36][37],, SO /TiO2-SiO2 [38][39][40][41], SrO/SO -ZrO2 [29], SO /ZrO2 [17,[42][43][44], SO /TiO2-ZrO2 [45] and SO /SnO2 [17,46], which were considered for a good catalytic activity for the raw materials containing large amounts of FFA in biodiesel production. Among these, sulphated doped TiO2 is a good example of a solid super-acidic catalyst which is also used in the petrochemical industry and petroleum refining process [24,47] and showed better performances as compared to other sulphated metal oxides.…”

Photocatalytic Degradation of Rhodamine B over Sulfated SiO2-TiO2 Composite by Sulphuric Acid Impregnation Method

“…SO 4 2− /TiO 2 has been studied by many groups (14,(17)(18)(19)(20). Mixed zirconium and titanium sulphated oxides are reported as potential catalysts for the free fatty acids esterification reaction (21). The results demonstrated that the acidity and the surface area of catalysts play an important role in their catalytic performance.…”

Synthesis, Characterization and Catalytic Performance of a Novel Picolinic Acid-12-Molybdophosphoric Acid Hybrid Catalyst

“…9,10 Taking esterification reaction as an example, some heterogeneous acids have gained attention, which included ion exchange resins, zeolites, sulfated oxides, biomass carbon-based solid acid and heteropoly acids (HPAs). 6,[11][12][13][14][15][16][17] HPAs are typical strong Brønsted acids with low volatility, low corrosiveness and flexibility. 11,17 However, as a heterogeneous catalyst, the disadvantages of HPAs lie in their low surface area (1-10 m 2 g -1…”