Electroconductive porous inorganic material used as filter or sensor - contains porous inorganic substance, pref. aluminosilicate or aluminium phosphate, and semiconducting metal oxide, pref. tin di:oxide, carbon di:oxide and/or zinc oxide

摘要

Electroconductive porous inorganic material (I) contains porous inorganic substance (II) and 0.1-50 (wt.)% semi-conducting metal oxide (III). Pref. (III) is SnO2, CO2 and/or ZnO. (I) may also contain 0.1-10% oxide of another metal with valency less than 4 and/or 0.1-3% oxide of a metal catalysing the reaction of CO to CO2. (II) is an aluminosilicate or Al phosphate. The metal oxides are applied to the internal surface area or (partly) incorporated in the crystal lattive of (II). (I) is prepd. by coating the internal surface area of (II) with the metal oxides; or by preparing (II) in the presence of the metal oxides or their precursors. USE/ADVANTAGE - (I) is claimed for use as specific adsorption filter or sensor with specific electrical display. It is suitable for all purposes requiring a combination of adsorption and electrical conductivity, e.g. for specific adsorption of CO and NO (contg. small amts., e.g. up to 10 vol.% NO2) from gases contg. O2 and other constituents, e.g. N2. (I) has a resistivity of 10 exp. 6 to 10 exp. 9, esp. 10 exp. 8 to 10 exp. 9 k-ohmmm