Tetramethylguanidine covalently bonded onto silica gel surface as an efficient and reusable catalyst for transesterification of vegetable oil

摘要

A solid base catalyst was obtained through attachment of tetramethylguanidine onto silica gel surface. Infrared spectroscopy, ~(13)C and ~(29)Si nuclear magnetic resonance data are in agreement with the proposed structure. SEM images showed that the catalyst presented high homogeneous spherical particles of 1 μm with surface area of 216.14 ± 34 m~2 g~(-1). The obtained material was used as catalyst in the transesterification of soybean oil for biodiesel production. The catalytic efficiency was followed and the biodiesel conversion presented a yield of 86.73 ± 2.2% at 3 h of reaction. The catalyst was recovered and reused nine times, maintaining about 62% of its catalytic efficiency.