Study of preparation and properties on solid superacid sulfated titania–silica nanomaterials

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.…”

“…It was reported that the high surface acidity of titanium dioxide (SO /TiO2) increased the yield of butyl acetate to about 92.2% in esterification reaction and the selectivity of the catalyst mostly depended on the degree of exposure of reactive crystal facets. Yang et al [40] reported a novel strategy for the preparation of SO /TiO2-SiO2 nano-crystalline solid catalyst. The prepared nano-catalyst had a high surface area of 550m 2 /g compared to SO /TiO2 nano-catalyst.…”

Synthesis of isoamyl salicylate using a novel mesoporous titania superacid as a catalyst

“…In consideration of environmental and economic reasons, many researchers have made great efforts to replace conventional acid catalysts with newer solid superacid catalysts. For the past few decades, many kinds of solid superacid catalysts have been found, and they have been used widely in many areas [2][3][4][5][6][7][8][9]. This is principally attributed to the obvious advantages of solid superacid catalysts, such as their high acid strength, no corrosion for reactors, ease of handing, less expensive, and easy to recover and reuse [1,[10][11][12][13] as compared with traditional liquid acids.…”

“…However, conventional liquid acid H 2 SO 4 used in esterification generates great risks such as difficulty of handing, high waste generation and environmental problems and so on. Recently, in order to solve these problems, many kinds of solid superacids were used in esterification reactions as catalysts and they have exhibited excellent catalytic activities [8,21].…”

Photocatalytic destruction of gaseous toluene by sulfated TiO2 powder

“…This property is applicable to various acid catalytic reactions such as isomerization, cracking alkylation, and esterification [14][15][16][17][18][19]. It has been proposed that the strong acid property is related to sulfate ions, and that high electron negativity of sulfur can induce polarization of neighboring OH groups as was shown in Fig.…”