Synthesis of zeolite ferrierite–Role of emulsifiers

Abstract

Synthesis of ferrierite (FER) type zeolite using piperidine as templating agent has been studied in the presence of different types of emulsifier at various concentration levels. Use of cationic emulsifier (cetyl trimethyl ammonium bromide), results in amorphous phase, while with anionic emulsifier (sodium lauryl sulphate or SLS) and non-ionic emulsifier (sorbital mono stearate or Span 60), pure FER phases with close to nano-sized crystallites are obtained. Influence of a new non-ionic emulsifier (benzotriazole) has been investigated in detail. Effects of mode of synthesis (static or stirring), synthesis temperature and ratio of templating agent to benzotriazole are studied. Stirring of the synthesis gel in presence of benzotriazole results in pure FER phase with crystallite size of <500 nm. With the increase in benzotriazole to piperidine ratio, crystallinity of the FER phase reduces exponentially at 150°C due to lower crystallization rate. On the contrary at 170°C the increase in α quartz formation is observed with the increase in the benzotriazole to piperidine ratio.