Abstract: The invention relates to catalytic coating compositions for surfaces of cookers, ovens, fryers or grills, to a process for the preparation of these coating compositions, and to cookers, ovens, fryers or grills or parts thereof having surfaces provided with the coating compositions according to the invention.

Abstract: The use of zeolites rich in silicic acids having an Si:Al ratio of 1:1 to 100:1 as specific adsorbents for NO.sub.X or CO is proposed. Because of their property of specifically adsorbing NO.sub.X or CO, these zeolites, in particular those zeolites doped with such metals as Ca, Co, Ni, Fe, Cu, Ag, Pt or Ru, and having the above mentioned ratio of Si to Al, are especially suitable for the production of specific NO.sub.X or CO sensors based on semiconductors. Such sensors can be used as sensors for exhaust gases of automotive vehicles, for example.

Abstract: To simplify manufacture and assembly of a temperature-compensated titanium dioxide oxygen sensor, the sensor (9, 9') is applied as a layer on the thermistor body (1), with an electrode (8) interposed; preferably, the thermistor body is densely sintered titanium dioxide, in the form of a closed tube (1, 1') which may have a central opening (FIG. 1: 2) therethrough, with the sensor body being porous titanium dioxide and located either on the inside (FIG. 1) surface of the thermistor body (1) or on the outside (FIG. 2) surface, and supported by the thermistor body, which forms the substrate and support surface for the sensor body.

Abstract: Tin oxide doped with magnesium oxide or niobium pentoxide and prepared as a sintered material is found to be highly sensitive to oxygen partial pressure both in the presence of free oxygen and in the presence of oxidizable gases, such as carbon monoxide or the lower oxides of nitrogen, and even in the presence of mixtures of both, such as in the exhaust gas of an internal combustion engine. The electrical conductivity varies by substantially more than an order of magnitude in response to a change in the oxygen partial pressure of about one-half an order of magnitude. The doped oxides operate as poor catalysts for the oxidation of oxidizable components of the exhaust gases. Chromium oxide doped with tin oxide shows the effect of an excessively good catalysis from the point of view of range of measurement, but is usable to give a sharp indication of the appearance or disappearance of free oxygen in a gas mixture.

Abstract: The present invention provides a catalyst for converting the noxous CO, NO.sub.x and hydrocarbons found in the exhaust gases from internal combustion engines into less harmful gases, and to the method of treating said exhaust gases. The catalyst consists essentially of a solid solution of Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3, and Fe.sub.3 O.sub.4. The catalyst may be extended on a porous carrier such as aluminum oxide or aluminum silicate. The catalyst is particularly suited for treating the exhaust gas from internal combustion engines of motor vehicles.