On the promising performance of single Ta atom in efficient nitrogen fixation

Abstract

The electrocatalytic nitrogen reduction reaction (NRR) with atomic Ta catalysts as supported by carbon materials is investigated using a combination of experiments and theoretical calculations. The Ta catalysts were prepared via photodeposition (Ta-GO) and impregnation (Ta-NC), respectively. Surprisingly, the Ta-GO catalyst exhibits excellent NRR efficiency with an ammonia yield rate of 19.97 μ g N H 3 h − 1 m g C a t . − 1 (14.26 m g N H 3 h − 1 m g T a − 1 ) and a Faraday efficiency (FE) of 8.52%. By contrast, the Ta-NC species exhibits lower atomic efficiency (y NH3 = 17.71 μ g N H 3 h − 1 m g C a t . − 1 [3.34 m g N H 3 h − 1 m g T a − 1 ]) but higher NRR selectivity (FE = 17.86%). The reaction mechanisms have been revealed by computation, based on which the electronic origins for the performances of atomic Ta at different coordination environments are discussed. This work demonstrates the potential of Ta to conduct an efficient NRR process, and the promising electronic structure for constructing highly efficient Ta catalysts is discussed. • The Ta catalysts were prepared via photodeposition (Ta-GO) and impregnation (Ta-NC). • The Ta-GO exhibits an ammonia yield of 19.97 μ g N H 3 h − 1 m g C a t . − 1 and an FE of 8.52%. • Ta has the potential as the active center to conduct an efficient NRR process. In the field of ammonia synthesis, the traditional Haber-Bosch process requires high temperature and high pressure, while the hydrogen comes from fossil fuels, thus consuming a large amount of energy and causing environmental pollution. Electrochemical nitrogen reduction reaction (NRR) has been considered as an eco-friendly strategy for an alternative to the Haber-Bosch process under ambient conditions with renewable electricity from solar or wind sources, which is of great significance to the sustainable development of the national economy. The atomic Ta catalysts at different coordination environments as prepared for the NRR process by photodeposition (Ta-GO) and impregnation (Ta-NC), and the electrocatalytic performance has been investigated, which demonstrates the potential of Ta to conduct an efficient NRR process.