1. Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland21218, United States
2. Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland21218, United States
3. STC-K Intermediate Catalysis MEA, SABIC Technology Center at King Abdullah University of Science and Technology, Thuwal23955, Kingdom of Saudi Arabia
4. Material Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland20899, United States