One-pot synthesis of N-doped petroleum coke-based microporous carbon for high-performance CO2 adsorption and supercapacitors

•A simple and efficient one-pot synthesis route was successfully conducted.•Petroleum coke-based microporous carbon exhibits high CO2 uptake (4.25 mmol/g at 25°C and 1 bar) and specific capacitance (233.25 F/g at 0.5A/g).•Ultra-micropores and basic N species are crucial factors for the enhanced CO2 uptake and CO2/N2 selectivity respectively.•Waste resource utilization and global CO2 emission reduction can be realized simultaneously. Waste resource utilization of petroleum coke is crucial for achieving global carbon emission reduction. Herein, a series of N-doped microporous carbons were fabricated from petroleum coke using a one-pot synthesis method. The as-prepared samples had a large specific surface area (up to 2512 m2/g), a moderate-high N content (up to 4.82 at.%), and high population (55%) of ultra-micropores (