1 Supporting Information Synthesis of Birnessite in the Presence of Phosphate, Silicate or Sulfate Qian Wang, † Xianya Liao, † Wenqian Xu, ‡ Yang Ren, § Kenneth J. Livi, ┴ and Mengqiang Zhu *, † † Department of Ecosystem Science and Management, University of Wyoming, Laramie, Wyoming 82071, United States ‡ Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, United States § X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States ┴ Materials Characterization and Processing Center, Department of Materials Science and Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, United States *Corresponding author: Mengqiang Zhu Phone: 307-766-5523 E-mail: mzhu6@uwyo.edu