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

LaCoO3 and LaMnO3 gel films were deposited by dip-coating technique on yttr ia-stabilized zirconia (YSZ) substrate using the precursor solution prepare d from La(O-i-C3H7)(3), Co(CH3COO)(2) or Mn(O-i-C3H7)(2), 2-methoxyethanol, and polyethylene glycol. By heat-treating the gel films, electrochemical c ells, LaCoO3/YSZ/LaCoO3 were fabricated. The effect of polyethylene glycol on the microstructure evolution of LaCoO3 and LaMnO3 thin films was investi gated, and NO decomposition characteristics of LaCoO3 powders and the elect rochemical cells were investigated at 600-800 degreesC. In the absence of o xygen, the LaCoO3 powder was active both in decomposition of NO and reducti on of NO by C2H4. It was found that they lost their catalytic activity in t he presence of 2% oxygen. By applying a direct current to LaCoO3/YSZ/LaCoO3 electrochemical cell, a good NO conversion rate could be obtained at relat ively low current value even if excess oxygen is included in the reaction g as mixture. (C) 2001 Elsevier Science Ltd. All rights reserved.