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

摘要

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 m~2/g）,a moderate-high N content （up to 4.82 at.%）,and high population （55%） of ultra-micropores （＜0.7 nm）.Regulating the N content and ultra-microporosity led to efficient CO2adsorption and separation.At ambient pressure,the optimal N-doped petroleum coke-based microporous carbon exhibited the highest CO2uptake of 4.25 mmol/g at 25°C and 6.57 mmol/g at 0°C.These values are comparable or even better than those of numerous previously reported adsorbents prepared by multistep synthesis,primarily due to the existence of ultra-micropores.The sample exhibited excellent CO2/N2selectivity at25°C owing to the abundant basic pyridinic and pyrrolic N species;and showed superior CO2adsorption-desorption cycling performance,which was maintained at 97%after 10 cycles at25°C.Moreover,petroleum coke-based microporous carbon,with a considerably high specific surface area and hierarchical pore structure,exhibited excellent electrochemical performance over the N-doped sample,maintaining a favorable specific capacitance of 233.25F/g at 0.5 A/g in 6 mol/L KOH aqueous electrolyte.This study provides insight into the influence of N-doping on the porous properties of petroleum coke-based carbon.Furthermore,the as-prepared carbons were found to be promising adsorbents for CO2adsorption,CO2/N2separation and electrochemical application.