DOI: 10.5281/zenodo.7199930
title: Thermodynamic database and calculator of free energies and potentials for redox reactions involving iron minerals in aqueous media (IMTD)

description: Database of free energies of formation for iron minerals and associated aqueous species, which are used in a tableu style spreadsheet to calculate free energies of redox reactions involving iron minerals, which in turn are used to calculate free energies and formal potentials for these reactions, under specified environmental conditions. The database and calculators were assembled by students and postdocs (Jeff Hudson, Ania Pavitt, Ying Lan, and Miranda Bradley) working under direction of Professor Paul G. Tratnyek at the Oregon Health & Science University, Portland, Oregon, USA. Drew Latta, Thomas Robinson, and Michelle Scherer contributed to the database and extended the calculations. Early versions of this tool were used in several publications, including (i) Fan, D., Y. Lan, P. G. Tratnyek, R. L. Johnson, J. Filip, D. M. O'Carroll, A. N. Garcia, and A. Agrawal. 2017. <em>Environ. Sci. Technol.</em> 51(22): 13070–13085. [DOI: 10.1021/acs.est.7b04177] and (ii) Bradley, M. J., and P. G. Tratnyek. 2019. <em>ACS Earth & Space Chemistry</em> 3(3): 688-699. [DOI: 10.1021/acsearthspacechem.8b00200]. This tool is provided as a spreadsheet in .xlsx format. The file includes six sheets. The first contains background, constants, and calculations that apply throughout the remaining tabs. The second contains free energies of formation from various authoritative sources, and a mechanism for designating “recommend values”. The third contains a tableu that calculates free energies of redox reactions using the recommended free energy of formation and user-specified stoichiometries. The fourth calculates free energies and formal potentials of the redox reactions using the standard potentials, and specific solution conditions. The last tab summarizes previous published formal potentials from a variety of sources. While the database was checked thoroughly, it still is unlikely to be completely accurate. For critical applications, we recommend that you track-down the primary sources (listed on the first tab of the spreadsheet) and use them for data, conditions, and other caveats. Obviously, we do not accept any responsibility for what anyone does with information obtained from this document. In the future, if significantly corrections or additions are made to this document, we may publish it here as new versions. If the contributions of others result in major improvements, we are open to adding new authors to those versions. Feel free to contact us with corrections, suggests, or offers to help. The development of this version of the tool was funded through grants from the Strategic Environmental Research and Development Program (SERDP) and the U.S. Department of Energy.
description: The development of this version of the tool was funded through several research grants from the Strategic Environmental Research and Development Program (SERDP), including grants numbered ER-2308, ER-2619, ER-2620, and ER20-C4-1357. D.E.L.'s contribution was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division through its Geosciences program at Pacific Northwest National Laboratory (PNNL) and a subcontract to the University of Iowa. PNNL is a multiprogram national laboratory operated for the DOE by Battelle Memorial Institute under contract no. DE-AC05-76RL01830.