Operando Cu Aggregation-Induced Spin State Modulation in Fe–Cu Single Atom Catalyst for Enhanced Tandem Electrochemical Nitrate Reduction Reaction - Seongin Hong; Jaewoo Jeong; Euichan Yoo; Dongwoo Shin; Suhwan Yoo; Eunchong Lee; Hyungjun Kim; Hyeyoung Shin; Yun Jeong Hwang (Journal of the American Chemical Society, 2026)