Platinum electrodes for carbon monoxide detection in air - with lead doping of electrode or electrolyte, increasing sensitivity

摘要

Pb or Pb cpds. are added to Pt electrodes for the electrochemical detection of CO in air or to the electrolyte in which these are placed. The selectivity is increased by a factor of 2, i.e. to 2. 6 mu A/ppm cf. 1.4 m u A/ppm, allowing detection of CO in the 1-10 ppm range. The electrodes are less sensitive, by a factor of ca 10, to interference by other oxidisable substances, esp. hydrocarbons, the relative sensitivity being reduced to 0.07 and 0.043 respectively for C2H4 and NO, cf 0.58 and 0.39 for the undoped Pt electrode, w.r.t. a sensitivity of 1.00 for CO. The Pb doping also prevents damage by atmos. oxidn.