Spin-related Cu-Co pair to increase electrochemical ammonia generation on high-entropy oxides

Abstract The electrochemical conversion of nitrate to ammonia is a way to eliminate nitrate pollutant in water. Cu-Co synergistic effect was found to produce excellent performance in ammonia generation. However, few studies have focused on this effect in high-entropy oxides. Here, we report the spin-related Cu-Co synergistic effect on electrochemical nitrate-to-ammonia conversion using high-entropy oxide Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O. In contrast, the Li-incorporated MgCoNiCuZnO exhibits inferior performance. By correlating the electronic structure, we found that the Co spin states are crucial for the Cu-Co synergistic effect for ammonia generation. The Cu-Co pair with a high spin Co in Mg 0.2 Co 0.2 Ni…

• NR
  National Research Foundation
• AF
  Agency for Science, Technology and Research

  Awards: M22K2c0078, A19E9a0103
• NR
  National Research Foundation Singapore
• NS
  National Supercomputing Centre Singapore