Mechanistic modeling of NO electrochemical reduction in a micro-tubular cell: Effects of CO2/H2O components and electrochemical promotion

A two dimensional model coupling the mass balance and momentum balance processes was developed for a micro-tubular electrochemical cell for NOx reduction. The effect of electrochemical promotion of catalysis (EPOC) on NO decomposition was considered in the kinetic model. The cell was consisted of La0.6Sr0.4Co0.95Cu0.05O3−δ (LSCC)-Ce0.9Gd0.1O1.95 (GDC) catalytic electrode, YSZ electrolyte, Ni-YSZ anode. The model was validated by comparing the simulation results with experimental data from the literature. Parametric simulations were conducted to investigate the effects of CO2 and H2O on the NO conversion performance. Results revealed that the presence of CO2 and H2O are beneficial to the NO reduction. The improvement by H2O was stronger than that by CO2. The effects of temperature on NO conversion were investigated. The distributions of the gas compositions along the channel and catalytic electrode were discussed to analyze the inner diffusion and reaction processes. Gas flow rate was another influential factor and low gas velocity was advantageous for the NOx reduction reaction kinetics.