Electrochemical gas sensor for detecting hydrogen cyanide gas

A method for detecting hydrogen cyanide (HCN), the method comprising:

• receiving an ambient gas into a housing of an HCN sensor, wherein the ambient gas comprises HCN and hydrogen sulfide (H2S), and wherein the HCN sensor comprises a plurality of electrodes in contact with an electrolyte within the housing, wherein the plurality of electrodes comprises a porous working electrode and a counter electrode;
• filtering the H2S gas from the ambient gas;
• applying a voltage potential between the counter electrode and the working electrode;
• contacting the ambient gas with the porous working electrode;
• allowing the ambient gas to diffuse through the porous working electrode to contact the electrolyte;
• generating a current between the porous working electrode and the counter electrode in response to a reaction between the ambient gas and the electrolyte at the surface area of the working electrode;
• and
• determining a concentration of the HCN in the ambient gas based on the current.

An electrochemical hydrogen cyanide (HCN) sensor comprising:

• a housing comprising an opening allowing gas to enter the sensor;
• an electrolyte disposed within the housing;
• a plurality of electrodes in contact with the electrolyte within the housing, wherein the plurality of electrodes comprise a working electrode and a counter electrode, and wherein the electrodes comprise a metal catalytic material;
• and
• a filter operable to cover the opening of the housing, and prevent hydrogen sulfide (H2S) from reaching the electrodes, wherein the filter comprises silver sulfate layered onto a polytetrafluoroethylene (PTFE) support material.