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 Ce_0.9A_0.05Nb_0.05O₂ (A = Y, La, Sc) and Ce_xLa_(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 (p_O2 = 10⁻¹⁵–10⁻¹ atm). Undoped and single element doped ceria (Ce_0.9B_0.1O₂ where B = Y, La, Nb, Hf) served as a reference. At any given set of T and p_O2, the relative reduction extent follows Ce_0.9Hf_0.1O₂ > Ce_0.9Sc_0.05Nb_0.05O₂ > Ce_0.9Y_0.05Nb_0.05O₂ > Ce_xLa_(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. Ce_0.9Y_0.05Nb_0.05O₂ in particular can outperform undoped ceria and reach efficiency values of 31% and 28% for H₂ and CO production, respectively.

中文翻译：

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具有优异氧化还原性能的成对电荷补偿掺杂二氧化铈对H ₂ O和CO _2的太阳热化学分解的热力学

使用三价和五价阳离子的成对电荷补偿掺杂二氧化铈（PCCD）被评估为H ₂ O和CO ₂的热化学分解的氧化还原材料。分子式为Ce _0.9 A _0.05 Nb _0.05 O ₂（A = Y，La，Sc）和Ce _x La _{（1- x）/ 2} Nb _{（1- x）/ 2} O ₂（x = 0.75，0.95）是在热重分析仪中在一定温度（T = 1173–1773 K）和氧气分压（p _{O 2}= 10 ^-15 –10 ^-1 atm）。未掺杂和单元素掺杂的二氧化铈（Ce _0.9 B _0.1 O ₂，其中B = Y，La，Nb，Hf）用作参考。在任何给定的T和p _{O 2}集合下，相对还原程度均遵循Ce _0.9 Hf _0.1 O ₂ > Ce _0.9 Sc _0.05 Nb _0.05 O ₂ > Ce _0.9 Y _0.05 Nb _0.05 O ₂ > Ce _x La _{（1- x）/ 2}铌_{（1- x）/ 2} O ₂ > CeO ₂ >仅三价或五价掺杂的二氧化铈。使用与缺陷建模耦合的Van't Hoff分析确定部分摩尔还原焓，其范围为360至410 kJ mol ^-1。系统效率模型预测，由于这些PCCD材料具有平衡的还原和氧化特性，因此具有实现高太阳能到燃料能量转换效率的潜力。Ce _0.9 Y _0.05 Nb _0.05 O _2的性能尤其优于未掺杂的二氧化铈，并且对于H ₂和CO的生产，效率值分别达到31％和28％。