Shim, Jaehyuk Lee, Jaewoo Shin, Heejong Mok, Dong Hyeon Heo, Sungeun Paidi, Vinod K. Lee, Byoung-Hoon Lee, Hyeon Seok Yang, Juhyun Shin, Dongho Moon, Jaeho Kim, Kang Jung, Muho Lee, Eungjun Bootharaju, Megalamane S. Kim, Jeong Hyun Park, Subin Kim, Mi-Ju Glatzel, Pieter Yoo, Sung Jong Back, Seoin Lee, Kug-Seung Sung, Yung-Eun Hyeon, Taeghwan 2025-04-09T08:30:44Z 2025-04-09T08:30:44Z 2025-04-09 2025-04 0935-9648 https://pubs.kist.re.kr/handle/201004/152227 Electrochemically generating hydrogen peroxide (H2O2) from oxygen offers a more sustainable and cost-effective alternative to conventional anthraquinone process. In alkaline conditions, H2O2 is unstable as HO2-, and in neutral electrolytes, alkali cation crossover causes system instability. Producing H2O2 in acidic electrolytes ensures enhanced stability and efficiency. However, in acidic conditions, the oxygen reduction reaction mechanism is dominated by the inner-sphere electron transfer pathway, requiring careful consideration of both reaction and mass transfer kinetics. These stringent requirements limit H2O2 production efficiency, typically below 10-20% at industrial-relevant current densities (>300 mA cm(-2)). Using a multiscale approach that combines active site tuning with macrostructure tuning, this work presents an octahedron-like cobalt structure on interconnected hierarchical porous nanofibers, achieving a faradaic efficiency exceeding 80% at 400 mA cm(-2) and stable operation for over 120 h at 100 mA cm(-2). At 300 mA cm(-2), the optimized catalyst demonstrates a cell potential of 2.14 V, resulting in an energy efficiency of 26%. English WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Efficient H2O2 Electrosynthesis in Acidic media via Multiscale Catalyst Optimization Article 10.1002/adma.202418489 1 Advanced Materials, v.37, no.17 Advanced Materials 37 17 N scie scopus 001447081800001 2-s2.0-105000480071 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article OXYGEN REDUCTION HYDROGEN-PEROXIDE ELECTRON-TRANSFER ATOM SPECTROSCOPY hydrogen peroxide production inner-sphere electron transfer pathway multi-level tuning strategy octahedron-like cobalt structure H2O2 treatment