Hydrogenated Pyridine‐Pyrrole Nitrogen‐Doped Carbon for High‐Efficiency Electrosynthesis of Hydrogen Peroxide in NaCl Electrolyte
Huarui Xie, Jianjun Fu, Jia Liu, Bin Yang, Pei Kang Shen, Zhi Qun Tian
Abstract
Abstract Developing metal‐free carbon catalysts is critical to achieve the electrosynthesis of hydrogen peroxide (H 2 O 2 ) via two‐electron oxygen reduction reaction (2e − ORR) using seawater as electrolyte. Herein, N‐rich doped carbon (NC) is synthesized by directly pyrolyzing guanine as both N and C sources, which can facilitate the formation of ultrahigh‐N dopant (up to 33.89 at.%), and their ratios. The NC obtained at 700 °C with hydrogenated pyridine‐N and pyrrole‐N (3:2) dopants exhibits a superior selectivity of H 2 O 2 (up to 96%), high mass activity of 545.5 A g −1 at 0.2 V versus RHE and stable production of H 2 O 2 with 16.8 in 0.5 M NaCl. In situ Fourier transform infrared spectrum analysis proves that hydrogenated pyridine‐N and pyrrole‐N dopants play a critical role in constructing metal‐free active sites for the synthesis of H 2 O 2 . Meanwhile, theoretical calculations further reveal that compared to non‐hydrogenated N dopants, hydrogenated pyridine and pyrrole N can tune the projected density of states of 2p z orbitals of their adjacent carbon atoms approaching Fermi Level, enhancing * OOH to H 2 O 2 through 2e − ORR rather than H 2 O via 4e − ORR. This work provides new insights for developing metal‐free catalysts for efficient electrosynthesis of H 2 O 2 using seawater resources as promising electrolytes.