The medium temperature shift (MTS) microreactor has been proposed in order to decrease the CO content of reformate for fuel cell applications. The Ni-K/CeO2 catalyst is synthesized and coated on stainless-steel plates by electrophoretic deposition (EPD) and then evaluated at 300-390 degrees C. The morphology of the catalyst layers are analyzed by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and three-dimensional (3D) optical microscopy. The FT-IR analysis and conductivity measurements are used for slurry characteristics of different polyethylenimine (PEI) contents. The activity of the catalytic plates inside the microreactor is tested at different gas hourly space velocity (GHSV) values and H2O/CO molar ratio of 3. The CO conversion is raised by increasing the coating time from 1 min to 3 min, and it has an optimum at 140 V for applied voltage (between 30 V and 180 V). Also, it is found that the CO conversion is optimal at a PEI content of 0.3 wt %. Generally, the optimum conditions are achieved at 3 min, 140 V, and 0.3 wt % PEI, which results to 93% and 5.8% (GHSV = 12 000 mL h(-1) goat 71) for CO conversion and CH4 selectivity, respectively. Consequently, the results confirm the fact that the microreactor performance will be enhanced, compared to using a packed-bed reactor.