can be somewhat decreased if sodium hydroxide is used in combination with tetramethylammonium hydroxide the gels are heated under autogenous conditions at temperatures ranging from 100 to 250 u00b0 c preferably from 120 to 200 u00b0 c the ferrierite phase typically crystallizes within 48 hours of heating ferrierite seeds can be added to the gel to decrease the crystallization time in one embodiment a ferrierite zeolite for example cp 914c zeolyst international can be used for seeding in one embodiment the resulting ferrierite product is pure ferrierite and does not contain any other zeolitic or condensed silica impurities the ferrierite has a surface area of at least about 350 m 2 g or even at least about 380 m 2 g the ferrierite crystals have an irregular shape the average crystal size along all crystal dimensions is about or less than 200 nm as determined by scanning electron microscopy u201c sem u201d the resulting ferrierite can be converted to nh 4 form h form or loaded with metals either by impregnation or ion exchange for catalytic conversions of hydrocarbons selective catalytic reduction of nitrogen oxides or catalytic decomposition of nitrous oxide in one embodiment the ferrierite may be used as an inventive catalyst in a method for scr of exhaust gases such as by contacting the gas mixture with the ferrierite composition described herein embodiments of the invention will be further clarified by the following non limiting examples which are intended to be purely exemplary of the invention this example illustrates the synthesis of a small crystal ferrierite according to one embodiment of the present invention the molar composition of the gel was as.