Simultaneous decomposition of nitrogen oxides (NO x ) and solid state graphite particles were carried out using a 8 mol% Y 2 O 3 doped ZrO 2 (YSZ) based electrochemical reactor with a nano-structured NO x selective multilayer cathode and an oxidative porous anode. The ceramic electrochemical cell was prepared by screen-printing a Pt and a NiO–YSZ pastes as cathode layers and a 12 CaO7Al 2 O 3 –Pt paste as an anode layer on the YSZ electrolyte, respectively. Simultaneous decomposition of NO x and graphite particles was investigated using the cell with coated graphite particles on the surface of the 12 CaO7Al 2 O 3 –Pt composite anode in 1000 ppm NO x –He gas flow under applying DC voltage at 475 °C. The coated graphite particles at the anode were removed completely with 80% NO x decomposition by electrochemical reactions.