Affiliation:
1. School of Chemistry and Molecular Engineering East China Normal University Shanghai 200241 P. R. China
2. National Synchrotron Radiation Laboratory Key Laboratory of Precision and Intelligent Chemistry School of Nuclear Science and Technology University of Science and Technology of China Hefei 230029 P. R. China
3. Materials Engineering and Centre for Microscopy and Microanalysis University of Queensland Brisbane Queensland 4072 Australia
4. Australian Institute for Bioengineering and Nanotechnology The University of Queensland Brisbane QLD 4072 Australia
5. State Key Laboratory of Petroleum Molecular and Process Engineering SKLPMPE East China Normal University Shanghai 200062 P. R. China
Abstract
AbstractElectrocatalytic nitrate reduction reaction (NO3−RR) is an important route for sustainable NH3 synthesis and environmental remediation. Metal–organic frameworks (MOFs) are one family of promising NO3−RR electrocatalysts, however, there is plenty of room to improve in their performance, calling for new design principles. Herein, a MOF‐on‐MOF heterostructured electrocatalyst with interfacial dual active sites and build‐in electric field is fabricated for efficient NO3−RR to NH3 production. By growing Co‐HHTP (HHTP=2,3,6,7,10,11‐hexahydroxytriphenylene) nanorods on Ni‐BDC (BDC=1,4‐benzenedicarboxylate) nanosheets, experimental and theoretical investigations demonstrate the formation of Ni−O−Co bonds at the interface of MOF‐on‐MOF heterostructure, leading to dual active sites tailed for NO3−RR. The Ni sites facilitate the adsorption and activation of NO3−, while the Co sites boost the H2O decomposition to supply active hydrogen (Hads) for N‐containing intermediates hydrogenation on adjacent Ni sites, cooperatively reducing the energy barriers of NO3−RR process. Together with the accelerated electron transfer enabled by built‐in electric field, remarkable NO3−RR performance is achieved with an NH3 yield rate of 11.46 mg h−1 cm−2 and a Faradaic efficiency of 98.4 %, outperforming most reported MOF‐based electrocatalysts. This work provides new insights into the design of high‐performance NO3−RR electrocatalysts.