Solar thermochemical splitting of CO₂ into separate streams of CO and O₂ with high selectivity, stability, conversion, and efficiency

Abstract

Solar reactor technology for splitting CO2via a 2-step thermochemical redox cycle using concentrated solar radiation.

Modifying La0.6Sr0.4MnO3 Perovskites with Cr Incorporation for Fast Isothermal CO2‐Splitting Kinetics in Solar‐Driven Thermochemical Cycles

“…Each Cr2p spectrum was fitted using spin-orbital doublets centered at 576.1 and 585.9 eV ascribed respectively to Cr2p 3/2 and Cr2p 1/2 of Cr 3+ , spin-orbital doublets centered at 577.1 and 586.8 eV attributed respectively to Cr2p 3/2 and Cr2p 1/2 of Cr 4+ , and spin-orbital doublets centered at 580.0 and 589.5 eV, respectively due to Cr2p 3/2 and Cr2p 1/2 of Cr 6+ . 6 The presence of Cr 6+ has been previously reported in Cr-perovskites under oxidative conditions, [41] which in this case is very minor since SrCrO 4 was not detected by XRD either in the pristine material ( Figure 2 (Figure 8e).…”

“…6 is critical since Mn and Cr ions are the redox-active sites that participate in the oxygen exchange during the thermochemical cycling. 6 is critical since Mn and Cr ions are the redox-active sites that participate in the oxygen exchange during the thermochemical cycling.…”

“…[1,2] The utilization of concentrated solar energy to drive thermochemical cycles of metal oxides represents an attractive way to produce solar fuels via a two-step process through which CO 2 and H 2 O can be transformed into renewable syngas. [6] Exploring alternative materials that provide a higher oxygen release and better splitting kinetics (when compared to that of ceria) is of scientific and technological interest. In the second step, conventionally operated at a lower temperature, the reduced form of the metal oxide uptakes oxygen from CO 2 and H 2 O injected in the solar reactor, inducing splitting of the reactants by filling the oxygen vacancies of the oxide and producing CO and H 2 , commonly referred to as syngas (Equation (2a,b)).…”

Additive‐Manufactured Ordered Porous Structures Made of Ceria for Concentrating Solar Applications

“…The hollow tube along the center line originates from the burning of the 3D‐printed polymer template during sintering and exhibits less sharp edges compared with the RPC using polyurethane foam support. As the ordered and RPC structures were manufactured by the same replica‐based method, using the same ceria slurry, sintering protocol, and dimensions of the strut's inner hollow channel, the thermochemical stability of the ordered structures is expected to be comparable with that of the RPC structure subjected to the temperature‐swing operating conditions of a solar reactor . The cost of manufacturing was not assessed in this study.…”

Thermodynamics of paired charge-compensating doped ceria with superior redox performance for solar thermochemical splitting of H2O and CO2

“…The technical feasibility of this cycle has been experimentally demonstrated with a 5 kW solar reactor, yielding high selectivity, stability, mass conversion and solar-to-fuel energy efficiency. 10 However, due to its relatively low reducibility, pure ceria requires T > 1773 K and p O 2 < 10 mbar to achieve even moderate values of Dd. Doping ceria with tetravalent transition metals such as Zr 4+ (ref.…”