1. Department of Chemistry, Stanford University, Stanford, CA 94305, USA.
2. Department of Microbial and Molecular Systems, Centre for Sustainable Catalysis and Engineering, KU Leuven–University of Leuven, B-3001 Leuven, Belgium.
3. Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA.