Abstract: The modified activated coke (AC-N) supported Ni-Ce transition metal catalyst prepared by incipient-wetness impregnation method can simultaneously catalyze the ammonia selective catalytic reduction (NH₃-SCR) reaction and CO oxidation reaction, realizing the removal of NO and CO under low temperature and oxygen-rich conditions. The Ni-Ce /AC-N catalyst can achieve high-efficiency conversion of NO and CO at 175–250 ℃, and the conversion rates of NO and CO are both above 95% in this temperature range. After modified by nitric acid, the active coke support has a stronger interaction with metal components, which is conducive to better dispersion of the active components on the catalyst surface, and improves the specific surface area and redox capacity of the catalyst. The synergistic effect between Ni and Ce results in more Ni²⁺ and Ce³⁺ species on the catalyst surface, which is beneficial to the improvement of catalytic activity.