Selective Pathway of Nitrogen Reduction Controlled by Symmetry Breaking in BiErRu 2 O 7 Pyrochlores

The production of ammonia (NH 3 ) from nitrogen (N 2 ) in mild electrochemical conditions is of prime importance to obtaining sustainable fertilizers and carbon-free energy conversion, which strongly depends on the electronic occupation state at reactive sites. Herein, the structural symmetry breaking is regulated to rearrange spin electron configuration in an effort to optimize the reaction pathway of nitrogen reduction. The structure distortion is achieved in multistage-coupled BiErRu 2 O 7 pyrochlores by controlling the bonding interaction from Bi-6s lone pair electrons. The results demonstrate that the structural symmetry breaking can effectively optimize the bonding interaction and charge transfer between active sites and reactants, finally leading to the selection of reaction pathway from N 2 to NH 3 . Graphical Abstract The structural symmetry breaking is regulated to rearrange spin electron configuration in multistage-coupled BiErRu 2 O 7 pyrochlores, which can effectively optimize the bonding interaction and charge transfer between active sites and reactants, finally leading to the selection of reaction pathway from N 2 to NH 3 .