Production of silver-doped analcime by isomorphous substitution technique

Abstract

BACKGROUND: Metal-exchanged zeolites have been reported to have significant limitations on cayalytic activity, such as counterbalancing the negative framework charges and limitation of active space. Alternative methods of incorporating silver ions into the framework of zeolites are therefore necessary. This paper reports on a technique for producing silver doped analcime by isomorphous substitution of silver ion into the framework of analcime. The amount of aluminium in the gel composition was reduced by a factor of 5%, 10% and 20% and an equivalent amount of silver was added to the gel and treated in a conventional manner for zeolite crystallisation. Some of the aluminium in the reaction gel was replaced with the silver. The silver-doped analcime samples where characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-rays (EDX), Fourier transform infrared (FTIR) spectroscopy and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analysis.