Electrocatalytic N-2 reduction reaction (NRR) into ammonia (NH3), especially if driven by renewable energy, represents a potentially clean and sustainable strategy for replacing traditional Haber-Bosch process and dealing with climate change effect. However, electrocatalytic NRR process under ambient conditions often suffers from low Faradaic efficiency and high overpotential. Developing newly regulative methods for highly efficient NRR electrocatalysts is of great significance for NH3 synthesis. Here, we propose an interfacial engineering strategy for designing a class of strongly coupled hybrid materials as highly active electrocatalysts for catalytic N-2 fixation. X-ray absorption near-edge spectroscopy (XANES) spectra confirm the successful construction of strong bridging bonds (Co-N/S-C) at the interface between CoSx nanoparticles and NS-G (nitrogen- and sulfur-doped reduced graphene). These bridging bonds can accelerate the reaction kinetics by acting as an electron transport channel, enabling electrocatalytic NRR at a low overpotential. As expected, CoS2/NS-G hybrids show superior NRR activity with a high NH3 Faradaic efficiency of 25.9% at -0.05 V versus reversible hydrogen electrode (RHE). Moreover, this strategy is general and can be extended to a series of other strongly coupled metal sulfide hybrids. This work provides an approach to design advanced materials for ammonia production.
1.Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei 230026, Anhui, Peoples R China 2.Univ Sci & Technol China, Collaborat Innovat Ctr Chem Energy Mat, Hefei 230026, Anhui, Peoples R China 3.Univ Sci & Technol China, Chinese Acad Sci, Key Lab Mech Behav & Design Mat, Hefei 230026, Anhui, Peoples R China 4.Univ Sci & Technol China, Natl Synchrotron Radiat Lab, Hefei 230029, Anhui, Peoples R China
Recommended Citation:
Chen, Pengzuo,Zhang, Nan,Wang, Sibo,et al. Interfacial engineering of cobalt sulfide/graphene hybrids for highly efficient ammonia electrosynthesis[J]. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA,2019-01-01,116(14):6635-6640