Here, thermochemical looping splitting of water and carbon dioxide (CO2) with greenhouse-gas-free (GHG-free) energy has the potential to help address the Gt-scale GHG emissions challenge. Reaction thermodynamics largely contributes to the main bottlenecks of cost reduction for thermochemical looping water/CO2 splitting cycle. Here, we analyze thermodynamic driving forces in such cycles with two-phase ternary ferrites as model systems. We find that cation configurational entropy chiefly determines the change of partial molar entropy with oxygen stoichiometry. In addition, our phase diagram analysis accurately predicts the optimal Fe ratio for maximal water/CO2 splitting capacity in thermal reduction and in chemical reduction based cycles, underlining the significance of phase boundary positions. With chemical reduction, >10% CO2 conversion and high oxygen exchange capacity can both be achieved. Furthermore, our reduced Gibbs free energy model illustrates critical thermodynamic factors that influence the water/CO2 splitting capacity. Our research reveals the thermodynamic driving forces underlying the unconventional high-capacity Fe-poor ferrites, further explained via phase diagrams of Fe–Co–O, Fe–Ni–O and Fe–Mg–O. Future materials improvements can be guided by our reduced Gibbs free energy model.
Zhai, Shang, et al. "Thermodynamic guiding principles of high-capacity phase transformation materials for splitting H<sub>2</sub>O and CO<sub>2</sub> by thermochemical looping." Journal of Materials Chemistry. A, vol. 10, no. 7, Jan. 2022. https://doi.org/10.1039/d1ta10391a
Zhai, Shang, Nam, Joonhyun, Sai Gautam, Gopalakrishnan, Lim, Kipil, Rojas, Jimmy, Toney, Michael F., Carter, Emily A., Jung, In-Ho, Chueh, William C., & Majumdar, Arun (2022). Thermodynamic guiding principles of high-capacity phase transformation materials for splitting H<sub>2</sub>O and CO<sub>2</sub> by thermochemical looping. Journal of Materials Chemistry. A, 10(7). https://doi.org/10.1039/d1ta10391a
Zhai, Shang, Nam, Joonhyun, Sai Gautam, Gopalakrishnan, et al., "Thermodynamic guiding principles of high-capacity phase transformation materials for splitting H<sub>2</sub>O and CO<sub>2</sub> by thermochemical looping," Journal of Materials Chemistry. A 10, no. 7 (2022), https://doi.org/10.1039/d1ta10391a
@article{osti_1862336,
author = {Zhai, Shang and Nam, Joonhyun and Sai Gautam, Gopalakrishnan and Lim, Kipil and Rojas, Jimmy and Toney, Michael F. and Carter, Emily A. and Jung, In-Ho and Chueh, William C. and Majumdar, Arun},
title = {Thermodynamic guiding principles of high-capacity phase transformation materials for splitting H<sub>2</sub>O and CO<sub>2</sub> by thermochemical looping},
annote = {Here, thermochemical looping splitting of water and carbon dioxide (CO2) with greenhouse-gas-free (GHG-free) energy has the potential to help address the Gt-scale GHG emissions challenge. Reaction thermodynamics largely contributes to the main bottlenecks of cost reduction for thermochemical looping water/CO2 splitting cycle. Here, we analyze thermodynamic driving forces in such cycles with two-phase ternary ferrites as model systems. We find that cation configurational entropy chiefly determines the change of partial molar entropy with oxygen stoichiometry. In addition, our phase diagram analysis accurately predicts the optimal Fe ratio for maximal water/CO2 splitting capacity in thermal reduction and in chemical reduction based cycles, underlining the significance of phase boundary positions. With chemical reduction, >10% CO2 conversion and high oxygen exchange capacity can both be achieved. Furthermore, our reduced Gibbs free energy model illustrates critical thermodynamic factors that influence the water/CO2 splitting capacity. Our research reveals the thermodynamic driving forces underlying the unconventional high-capacity Fe-poor ferrites, further explained via phase diagrams of Fe–Co–O, Fe–Ni–O and Fe–Mg–O. Future materials improvements can be guided by our reduced Gibbs free energy model.},
doi = {10.1039/d1ta10391a},
url = {https://www.osti.gov/biblio/1862336},
journal = {Journal of Materials Chemistry. A},
issn = {ISSN 2050-7488},
number = {7},
volume = {10},
place = {United States},
publisher = {Royal Society of Chemistry},
year = {2022},
month = {01}}
SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Fuel Cell Technologies Office; USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC), Basic Energy Sciences (BES); Office of Naval Research (ONR); Stanford SUNCAT; Stanford TomKat
Grant/Contract Number:
AC02-76SF00515; EE0008090
OSTI ID:
1862336
Alternate ID(s):
OSTI ID: 1841269 OSTI ID: 1962555
Journal Information:
Journal of Materials Chemistry. A, Journal Name: Journal of Materials Chemistry. A Journal Issue: 7 Vol. 10; ISSN 2050-7488
SolarPACES 2017: International Conference on Concentrating Solar Power and Chemical Energy Systems, AIP Conference Proceedingshttps://doi.org/10.1063/1.5067139
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 368, Issue 1923https://doi.org/10.1098/rsta.2010.0119