@article{5159cab20dc94c56b924eb724fa33e47,
title = "Counter Cations Affect Transport in Aqueous Hydroxide Solutions with Ion Specificity",
abstract = "The anomalously high mobility of hydroxide and hydronium ions in aqueous solutions is related to proton transfer and structural diffusion. The role of counterions in these solutions, however, is often considered to be negligible. Herein, we explore the impact of alkali metal counter cations on hydroxide solvation and mobility. Impedance measurements demonstrate that hydroxide mobility is attenuated by lithium relative to sodium and potassium. These results are explained by ab initio molecular dynamics simulations and experimental vibrational hydration shell spectroscopy, which reveal substantially stronger ion pairing between OH- and Li+ than with other cations. Hydration shell spectra and theoretical vibrational frequency calculations together imply that lithium and sodium cations have different effects on the delocalization of water protons donating a hydrogen bond to hydroxide. Specifically, lithium leads to enhanced proton delocalization compared with sodium. However, proton delocalization and the overall diffusion process are not necessarily correlated. {\textcopyright}",
author = "Drexler, {Chad I.} and Miller, {Tierney C.} and Rogers, {Bradley A.} and Li, {Yuguang C.} and Daly, {Clyde A.} and Tinglu Yang and Corcelli, {Steven A.} and Cremer, {Paul S.}",
note = "Funding Information: P.S.C. thanks the National Science Foundation (CHE-1709735). Funding Information: P.S.C. thanks the National Science Foundation (CHE-1709735) for support. We thank Dor Ben-Amotz for providing the SMCR software in Igor Pro and for insightful discussions in implementing the algorithm. We thank Tawanda Zimudzi and Josh Stapleton of Penn State{\textquoteright}s Materials Characterization Lab for help with the collection of IR data. We thank Thomas E. Mallouk for insightful discussions concerning EIS data and equivalent electrochemical circuit models. S.A.C. thanks the National Science Foundation (CHE-1565471) for support. The authors are grateful for high-performance computing resources and support from the Center for Research Computing at the University of Notre Dame. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1548562. XSEDE resources Bridges at Pittsburgh Supercomputing Center and Comet at San Diego Supercomputer Center were used through allocations TG-CHE180017, TG-TRA140029, and TG-PHY130048. Publisher Copyright: Copyright {\textcopyright} 2019 American Chemical Society.",
year = "2019",
month = may,
day = "1",
doi = "10.1021/jacs.8b13458",
language = "English (US)",
volume = "141",
pages = "6930--6936",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "17",
}