Synthesis, characterization and catalytic properties of monodispersed nano-sphere silica sulfuric acid

In this research, the first report on synthesis of nano-sphere silica sulfuric acid (NS-SSA) as new catalyst was reported. The catalyst was prepared by the reaction of nano-sphere silica with chlorosulfonic acid at room temperature. The catalyst has been identified using various techniques (XRD, SEM, TEM, EDX, TGA, FT-IR) and results were shown that it was a spherical shape and its particle size was between 60 and 90 nm. The catalyst can be easily recovered and reused for seventeen reaction cycles for protection of amines without considerable loss of activity. It was found that the catalyst can be efficiently in large scale and we examined some reactions in scales of 50 and 100 mmol. Also, this method has some advantages such as high TOF of catalyst, chemoselectivity, easy work-up and short reaction time.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (160 K)Download as PowerPoint slideHighlights► Synthesis of nano-sphere silica sulfuric acid (NS-SSA). ► Application of nano-sphere silica sulfuric acid in the protection of amines. ► Catalysis under room temperature and solvent free medium. ► Easy work-up, chemoselectivity, 17 cycles recovery, the large scale reaction.