Gas sensor

Abstract

An electrochemical gas sensor is provided. The gas sensor includes a first electrode and a second electrode wherein the two electrodes are connected via an ion-conducting material. The first electrode is covered, at least in part, by a first catalytically active material. This top layer permits the catalytic reaction of gases. Thermally and chemically stable catalysts such as SCR or NO x storage catalysts or zeoliths are used as the top layer.

1 .- 29 . (canceled) 
     
     
         30 . An electrochemical gas sensor, comprising:
 a first electrode; and   a second electrode,   wherein the electrodes are connected via an ion-conducting material, and   wherein the first electrode is covered, at least in part, by a first catalytically active material.   
     
     
         31 . The electrochemical gas sensor as claimed in  claim 30 , wherein at least 20% of the first electrode consists of a metal. 
     
     
         32 . The electrochemical gas sensor as claimed in  claim 30 , wherein the electrodes consist of the same material. 
     
     
         33 . The electrochemical gas sensor as claimed in  claim 30 , further comprising a further first electrode that is covered, at least in part, by a second catalytically active material. 
     
     
         34 . The electrochemical gas sensor as claimed in  claim 33 , wherein the first catalytically active material is different to the second catalytically active material. 
     
     
         35 . The electrochemical gas sensor as claimed in  claim 30 , comprising one second electrode. 
     
     
         36 . The electrochemical gas sensor as claimed in  claim 30 , wherein the first catalytically active material exhibits a specific resistance of at least 1 μΩm at temperatures below 800° C. 
     
     
         37 . The electrochemical gas sensor as claimed in  claim 30 , wherein the second electrode is covered, at least in part, by the second catalytically active material. 
     
     
         38 . The electrochemical gas sensor as claimed in  claim 37 , wherein the first catalytically active material is different from the second catalytically active material. 
     
     
         39 . The electrochemical gas sensor as claimed in  claim 30 , wherein the first and/or second catalytic material comprises a SCR catalyst or a NO x  storage catalyst. 
     
     
         40 . The electrochemical gas sensor as claimed in  claim 30 , wherein the first and/or second catalytic material is porous. 
     
     
         41 . The electrochemical gas sensor as claimed in  claim 30 , wherein the second electrode is covered, at least in part, by a protective material. 
     
     
         42 . The electrochemical gas sensor as claimed in  claim 30 , comprising at least a heating element. 
     
     
         43 . The electrochemical gas sensor as claimed in  claim 42 , wherein the heating element is configured such that the first and second electrodes may be heated to different temperatures at the same time. 
     
     
         44 . The electrochemical gas sensor as claimed in  claim 43 , comprising an equipotential layer between the heating element and the first and second electrodes. 
     
     
         45 . The electrochemical gas sensor as claimed in  claim 30 , further comprising a temperature sensor. 
     
     
         46 . The electrochemical gas sensor as claimed in  claim 45 , wherein the temperature sensor and the heating element are formed as a single element. 
     
     
         47 . A combined gas sensor, comprising:
 an electrochemical gas sensor, comprising:
 a first electrode, and 
 a second electrode; and 
   a resistive gas sensor,   wherein the electrodes are connected via an ion-conducting material, and   wherein the first electrode is covered, at least in part, by a first catalytically active material, and   wherein the resistive gas sensor is formed by providing a third electrode in such a way that it is in direct contact with the first catalytic material and is not in direct contact with the first electrode.   
     
     
         48 . A method for producing an electrochemical gas sensor, comprising:
 providing an ion-conducting material;   producing a first electrode in conjunction with the ion-conducting material;   producing a second electrode in conjunction with the ion-conducting material; and   attaching a first catalytic material to the first electrode in such a way that the first electrode is covered by the first catalytic material, at least in part.   
     
     
         49 . The method for operating an electrochemical gas sensor as claimed in  claim 48 , wherein an electrical voltage is determined as a measuring signal between the first electrode and the second electrode.