B-N Pairs Enriched Defective Carbon Nanosheets for Ammonia Synthesis with High Efficiency
Chen, C (Chen, Chen)[ 1 ] ; Yan, DF (Yan, Dafeng)[ 1 ] ; Wang, Y (Wang, Yu)[ 2 ] ; Zhou, YY (Zhou, Yangyang)[ 1 ] ; Zou, YQ (Zou, Yuqin)[ 1 ]*; Li, YF (Li, Yafei)[ 2 ]*（李亚飞） ; Wang, SY (Wang, Shuangyin)[ 1 ]*
[ 1 ] Hunan Univ, Coll Chem & Chem Engn, State Key Lab Chem Biosensing & Chemometr, Changsha 410082, Hunan, Peoples R China
[ 2 ] Nanjing Normal Univ, Coll Chem & Mat Sci, Nanjing 210023, Jiangsu, Peoples R China
Electrochemical synthesis has garnered attention as a promising alternative to the traditional Haber-Bosch process to enable the generation of ammonia (NH3) under ambient conditions. Current electrocatalysts for the nitrogen reduction reaction (NRR) to produce NH3 are comprised of noble metals or transitional metals. Here, an efficient metal-free catalyst (BCN) is demonstrated without precious component and can be easily fabricated by pyrolysis of organic precursor. Both theoretical calculations and experiments confirm that the doped BN pairs are the active triggers and the edge carbon atoms near to BN pairs are the active sites toward the NRR. This doping strategy can provide sufficient active sites while retarding the competing hydrogen evolution reaction (HER) process; thus, NRR with high NH3 formation rate (7.75 mu g h(-1) mg(cat.)(-1)) and excellent Faradaic efficiency (13.79%) are achieved at -0.3 V versus reversible hydrogen electrode (RHE), exceeding the performance of most of the metallic catalysts.