Preparation of LaCoO3 catalytic thin film by the sol–gel process and its NO decomposition characteristics

Abstract

LaCoO 3 and LaMnO 3 gel films were deposited by dip-coating technique on yttria-stabilized zirconia (YSZ) substrate using the precursor solution prepared from La(O-i-C 3 H 7 ) 3 , Co(CH 3 COO) 2 or Mn(O-i-C 3 H 7 ) 2 , 2-methoxyethanol, and polyethylene glycol. By heat-treating the gel films, electrochemical cells, LaCoO 3 YSZ LaCoO 3 were fabricated. The effect of polyethylene glycol on the microstructure evolution of LaCoO 3 and LaMnO 3 thin films was investigated and NO decomposition characteristics of LaCoO 3 powders and the electrochemical cells were investigated at 600-800°C. In the absence of oxygen, the LaCoO 3 powder was active both in decomposition of NO and reduction of NO by C 2 H 4 . It was found that they lost their catalytic activity in the presence of 2% oxygen. By applying a direct current to LaCoO 3 /YSZ/LaCoO 3 electrochemical cell, a good NO conversion rate could be obtained at relatively low current value even if excess oxygen is included in the reaction gas mixture.