Efficient CO2 electroreduction over N-doped hieratically porous carbon derived from petroleum pitch

Abstract

Abstract Developing of economic and efficient catalysts is critical for the application of electroreduction of carbon dioxide to highly valuable chemicals. Herein, we present a facile method to synthesize N-doped hieratically porous carbon through pyrolysis of petroleum pitch followed by ammonia etching. We found mesopores are favored formation by removing of asphaltene from petroleum pitch during the carbonation process. Simultaneously, ammonia etching can not only increase the pyridinic-N content, but also upgrade the ratio of meso- to micro- pores of carbon materials. Using the N-doped hieratically porous carbon as catalyst for carbon dioxide electroreduction, the Faradaic efficiency of carbon monoxide reaches 83% at −0.9 V vs. the reversible hydrogen electrode (RHE) in 0.1 M KHCO3. This superior performance is attributed to the synergistic effects of highly pyridinic-N content in conjunction with the hieratically porous architecture, rendering abundant exposed and accessible active sites for electroreduction of CO2. Our work provides a new strategy for the large-scale preparation of high-performance, low-cost catalysts for CO2 electroreduction.