Abstract
The catalytic performance of SAPO-34 catalysts which were synthesised hydrothermally under different conditions was investigated in methanol-to-olefins reactions. The significance of template, silicon sources and crystallisation time on catalytic performance, and deactivation of SAPO-34 catalysts, were studied. High methanol conversion and yield of light olefins were obtained over the nano-sized catalyst synthesised with tetraethylammonium hydroxide as template source and tetraethyl orthosilicate as silica source with a crystallisation time of 24 h, owing to its higher crystallinity and smaller crystal size. The SAPO-34 catalysts with larger sizes of crystals deactivate rapidly, while smaller crystals retain their activity for a longer time.