TY - JOUR
T1 - Thermodynamics of paired charge-compensating doped ceria with superior redox performance for solar thermochemical splitting of H2O and CO2
AU - Hoes, Marie
AU - Muhich, Christopher L.
AU - Jacot, Roger
AU - Patzke, Greta R.
AU - Steinfeld, Aldo
N1 - Funding Information:
We gratefully acknowledge the nancial support by the Swiss National Science Foundation (Project REDOX – Grant No. 200021_162435), the Swiss State Secretariat for Education, Research and Innovation (Grant No. 15.0330), the EU's Horizon 2020 research and innovation program (Project SUN-to-LIQUID – Grant No. 654408), the European Research Council Advanced Grant (Project SUNFUELS – Grant No. 320541), and the University of Zurich Research Priority Program for Solar Light to Chemical Energy Conversion (LightChEC).
Publisher Copyright:
© 2017 The Royal Society of Chemistry.
PY - 2017
Y1 - 2017
N2 - Paired charge-compensating doped ceria (PCCD) using trivalent and pentavalent cations are evaluated as redox materials for the thermochemical splitting of H2O and CO2. The oxygen nonstoichiometries of PCCD materials with formulas of Ce0.9A0.05Nb0.05O2 (A = Y, La, Sc) and CexLa(1-x)/2Nb(1-x)/2O2 (x = 0.75, 0.95) were measured in a thermogravimetric analyzer over a range of temperatures (T = 1173-1773 K) and oxygen partial pressures (pO2 = 10-15-10-1 atm). Undoped and single element doped ceria (Ce0.9B0.1O2 where B = Y, La, Nb, Hf) served as a reference. At any given set of T and pO2, the relative reduction extent follows Ce0.9Hf0.1O2 > Ce0.9Sc0.05Nb0.05O2 > Ce0.9Y0.05Nb0.05O2 > CexLa(1-x)/2Nb(1-x)/2O2 > CeO2 > solely trivalent or pentavalent doped ceria. The partial molar reduction enthalpies were determined using Van't Hoff analysis coupled to defect modeling and range from 360 to 410 kJ mol-1. A system efficiency model predicts that these PCCD materials have the potential of achieving high solar-to-fuel energy conversion efficiencies because of their balanced reduction and oxidation properties. Ce0.9Y0.05Nb0.05O2 in particular can outperform undoped ceria and reach efficiency values of 31% and 28% for H2 and CO production, respectively.
AB - Paired charge-compensating doped ceria (PCCD) using trivalent and pentavalent cations are evaluated as redox materials for the thermochemical splitting of H2O and CO2. The oxygen nonstoichiometries of PCCD materials with formulas of Ce0.9A0.05Nb0.05O2 (A = Y, La, Sc) and CexLa(1-x)/2Nb(1-x)/2O2 (x = 0.75, 0.95) were measured in a thermogravimetric analyzer over a range of temperatures (T = 1173-1773 K) and oxygen partial pressures (pO2 = 10-15-10-1 atm). Undoped and single element doped ceria (Ce0.9B0.1O2 where B = Y, La, Nb, Hf) served as a reference. At any given set of T and pO2, the relative reduction extent follows Ce0.9Hf0.1O2 > Ce0.9Sc0.05Nb0.05O2 > Ce0.9Y0.05Nb0.05O2 > CexLa(1-x)/2Nb(1-x)/2O2 > CeO2 > solely trivalent or pentavalent doped ceria. The partial molar reduction enthalpies were determined using Van't Hoff analysis coupled to defect modeling and range from 360 to 410 kJ mol-1. A system efficiency model predicts that these PCCD materials have the potential of achieving high solar-to-fuel energy conversion efficiencies because of their balanced reduction and oxidation properties. Ce0.9Y0.05Nb0.05O2 in particular can outperform undoped ceria and reach efficiency values of 31% and 28% for H2 and CO production, respectively.
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U2 - 10.1039/c7ta05824a
DO - 10.1039/c7ta05824a
M3 - Article
AN - SCOPUS:85029648088
SN - 2050-7488
VL - 5
SP - 19476
EP - 19484
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 36
ER -