Journal of Inorganic Materials ›› 2022, Vol. 37 ›› Issue (2): 223-229.DOI: 10.15541/jim20210164

Special Issue: 【虚拟专辑】计算材料 【能源环境】CO2绿色转换

• RESEARCH LETTER • Previous Articles     Next Articles

Thermodynamic and First-principles Assessments of Materials for Solar-driven CO2 Splitting Using Two-step Thermochemical Cycles

FENG Qingying, LIU Dong, ZHANG Ying, FENG Hao, LI Qiang   

  1. School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
  • Received:2021-03-15 Revised:2021-05-20 Published:2022-02-20 Online:2021-06-10
  • Contact: ZHANG Ying, PhD. E-mail: ying.zhang@njust.edu.cn; LI Qiang, professor. E-mail: liqiang@njust.edu.cn
  • About author:FENG Qingying(1996-), female, PhD candidate. E-mail: fqy@njust.edu.cn
  • Supported by:
    Basic Science Center Program for Ordered Energy Conversion of the National Natural Science Foundation of China (51888103); National Natural Science Foundation of China (52006103); Fundamental Research Funds of the Central Universities (30919011403, 30920021137)

Abstract: Carbon-neutral fuel production by solar-driven two-step thermochemical carbon dioxide splitting provides an alternative to fossil fuels as well as mitigates global warming. The success of this technology relies on the advancements of redox materials. Despite the recognition of the entropic effect, usually energy descriptors (enthalpy of formation or energy of oxygen-vacancy formation) were used for computational assessment of material candidates. Here, in the first step, the criteria was derived based on the combination of solid-state change of entropy and formation enthalpy, and was used to thermodynamically assess the viability of material candidates. In the thermodynamic map, a triangular region, featuring large positive solid-state changes of entropy and small enough solid-state changes of formation enthalpy, was found for qualified candidates. Next, a first-principles DFT+U method was presented to fast and reasonably predict the solid-state changes of entropy and formation enthalpy of candidate redox materials, exemplified for pure and Samaria-doped ceria, so that new redox materials can be added to the thermodynamic map. All above results highlight the entropic contributions from polaron-defect vibrational entropy as well as ionic (oxygen vacancies) and electronic (polarons) configurational entropy.

Key words: carbon dioxide splitting, two-step thermochemical cycle, first principles, entropy, solar fuel

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