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Indexed by:期刊论文

Date of Publication:2018-02-01

Journal:ACS CATALYSIS

Included Journals:ESI热点论文、SCIE、EI、ESI高被引论文

Volume:8

Issue:2

Page Number:1186-1191

ISSN No.:2155-5435

Key Words:nitrogen fixation; ammonia synthesis; electrocatalysis; N-doped porous carbon; heterogeneous catalysis

Abstract:Ammonia has been used in important areas such as agriculture and clean energy. Its synthesis from the electrochemical reduction of N-2 is an attractive alternative to the industrial method that requires high temperature and pressure. Currently, electrochemical N-2 fixation has suffered from slow kinetics due to the difficulty of N-2 adsorption and N  N cleavage. Here, N-doped porous carbon (NPC) is reported as a cost-effective electrocatalyst for ammonia synthesis from electrocatalytic N-2 reduction under ambient conditions, where its N content and species were tuned to enhance N-2 chemical adsorption and N  N cleavage. The resulting NPC was effective for fixing N-2 to ammonia with a high ammonia production rate (1.40 mmol g(-1) h(-1) at-0.9 V vs RHE). Experiments combined with density functional theory calculations revealed pyridinic and pyrrolic N were active sites for ammonia synthesis and their contents were crucial for promoting ammonia production on NPC. The energy-favorable pathway for ammonia synthesis was *N  N -> *NH=NH -> *NH2-NH2 -> 2NH(3).