Researchers have been developing novel environment-friendly NH3-SCR catalysts for controlling NO_x emission from fossil fuel combustion. Fe doped CeO₂ catalysts with nanorod, nanocube and nanopolyhedron shape were synthesized and sulfation was conducted on porous nanorod simultaneously. Their NO_x conversions were in sequence of sulfated porous nanorod (S-FeCeO_x) > nanorod (R-FeCeO_x) > nanopolyhedron (P-FeCeO_x) > nanocube (C-FeCeO_x) and presented distinct morphology dependence. S-FeCeO_x catalyst possessed above 95 % NO_x conversion and nearly 100 % N₂ selectivity in very high gas hourly space velocity of 240, 000 mL·g^-1·h^-1 at 275-400 °C. The sequence of BET specific surface area was: P-FeCeO_x > R-FeCeO_x > S-FeCeO_x > C-FeCeO_x and thus the change of physical adsorption capacity may be not the main reason for high SCR catalytic activity of S-FeCeO_x and R-FeCeO_x. Fe doping and sulfation induced porous nanorod shape with preferentially exposed {110} faces, most oxygen vacancy defect sites and highest surface chemisorbed oxygen ratio, which contributed to the highest NO_x conversion of S-FeCeO_x. Fe doping mainly increased strong acid sites, and surface sulfate species significantly increased Bronsted acid sites promoting NH₃ adsorption and suppressed NOx adsorption on S-FeCeO_x catalyst, beneficial to both high NO_x conversion and low N₂O formation on it. R-FeCeO_x catalyst mainly followed Langmuir-Hinshelwood mechanism, while SCR reaction mechanism was changed by sulfation and S-FeCeO_x catalyst mainly followed Eley-Rideal mechanism.