Direct syntheses of a promising industrial organic–inorganic hybrid silica containing methanesulphonate

• Sulphonic groups are anchored on silica by the Si–O–Al–O–S covalent bond.
• Tetraethoxysilane is hydrolysed by formic acid in the absence of water.
• No structure-directing agents are used, and no wastewater is discharged.

A simple procedure was developed for the synthesis of sulphonic group-functionalised silica material (SAM) under formic acid conditions without the presence of surfactant species or precursors. The organic–inorganic hybrid materials exhibited high catalytic activity and excellent thermal stability in the alkylation of aromatics with olefins. Pyridine-FTIR indicated that SAM has abundant Lewis acid sites, especially weak acid sites. 29Si and 27Al MAS NMR confirmed that aluminium methanesulphonate was anchored on the surface of the silica matrix by the covalent bond of Si–O–Al.

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