One-step synergistic optimization of hierarchical pore topology and nitrogen dopants in activated coke for efficient catalytic oxidation of nitric oxide

Carbon-catalyzed oxidation represents a promising strategy for nitrogen oxide emission control. Here, we report a new strategy to simultaneously optimize the pore topology and doping environment of activated coke (AC) catalyst through one-step catalytic activation process with nitrogen resource in-situ participation. Dynamic experiments of nitric oxide catalytic oxidation using the prepared activated cokes with controllable pore configurations and doping environment firstly demonstrate that hierarchical pore configuration and nitrogen functional groups can synergistically improve catalytic oxidation activity. Especially, nitrogen-doped hierarchical porous AC catalyst exhibits the highest conversion efficiency (above 70%). Based on density functional theory calculations in combination with control experiments using pyridinic nitrogen and quaternary nitrogen-dominant catalysts, a new activity descriptor of electrophilic Fukui function is proposed and quaternary nitrogen is thereby identified to be the optimal nitrogen doping configuration towards nitric oxide catalytic oxidation. This work provides new insights into the synergistic role of pore topology and nitrogen doping in nitric oxide low-temperature oxidation, giving guidance for designing high-performance carbocatalyst. • N-doped hierarchically activated coke is prepared towards NO catalytic oxidation. • Enhanced activity stems from both hierarchical pore topology and nitrogen dopants. • Electrophilic Fukui function descriptor is proposed to elucidate the activity origin. • Quaternary N is demonstrated to be the most active among various N species.