Metal oxide semiconductor gas sensors utilising modified zeolite catalysts to improve selectivity

A novel method of improving the selectivity of metal oxide gas sensors has been developed by using catalytically active molecular sieve materials. They have been successfully introduced into a proprietary sensor array. The cracking patterns of linear alkanes over transition metal exchanged zeolites Y have been measured using a zeolite bed/GC/MS experimental set-zip within a temperature range of 300/spl deg/C to 400/spl deg/C. Studies have been carried out regarding the effects of metal loading, zeolite type, material fabrication techniques and operating temperature with regards to catalytic activity and selectivity. The composite sensors, utilising the novel zeolite materials, have been used in a custom built sensor rig that houses 3 dual electrode sensors and can measure real time responses of these sensors to an introduced headspace generated from organic liquids.