1. Department of Chemical System EngineeringFaculty of EngineeringUniversity of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan
2. Christian Doppler Laboratory for Sustainable SynGas ChemistryDepartment of ChemistryUniversity of Cambridge Lensfield Road Cambridge CB2 1EW UK
3. Current affiliation: Center for Energy & Environmental ScienceShinshu University 4-17-1 Wakasato, Nagano-shi Nagano 380-8553 Japan
4. National Synchrotron Radiation LaboratoryCollaborative Innovation Center of Chemistry for Energy MaterialsUniversity of Science & Technology of China Hefei Anhui 230029 P. R. China
5. Center for Energy & Environmental ScienceShinshu University 4-17-1 Wakasato, Nagano-shi Nagano 380-8553 Japan