Search for: All records

Structurally stabilized composites are promising for using phase change materials in high‐temperature thermal energy storage (TES). However, conventional skeleton materials, which typically comprise 30–50 wt% of the composite, mainly provide sensible heat storage and contribute minimally to overall energy density. This study introduces a new class of redox‐active oxide‐molten salt (ROMS) composites that overcome this limitation by combining sensible, latent, and thermochemical heat storage in a single particle. Specifically, porous, redox‐active Ca₂AlMnO_5+δ(CAM) complex oxide particles were demonstrated as a suitable support matrix, with the pores filled by eutectic NaCl/CaCl₂salt. X‐ray diffraction confirms excellent phase compatibility between CAM and the salt. Scanning electron microscopy/energy dispersive X‐ray spectroscopy and nano X‐ray tomography show good salt infiltration and wettability within the CAM pores. Thermogravimetric analysis reveals that a 60 wt% CAM/40 wt% salt composite achieves an energy density of 267 kJ kg⁻¹over a narrow 150 °C window, with ≈50 kJ kg⁻¹from thermochemical storage. Additionally, the composite shows higher thermal conductivity than salt alone, enabling faster energy storage and release. ROMS composites thus represent a novel and efficient solution for high‐performance TES. 

This study introduces a new family of redox-active oxide molten salt (ROMS) composites for high-capacity thermal energy storage. Porous perovskite oxides serve as active support materials, facilitating thermochemical energy storage... 

A new family of Isothermal, redox-activated CO₂sorbents were successfully developed using a high-throughput combinatorial approach to facilitate the generation of green hydrogen from biogenic carbonaceous feedstocks. 

Abstract Sorption-enhanced steam reforming (SESR) of toluene (SESRT) using catalytic CO₂sorbents is a promising route to convert the aromatic tar byproducts formed in lignocellulosic biomass gasification into hydrogen (H₂) or H₂-rich syngas. Commonly used sorbents such as CaO are effective in capturing CO₂initially but are prone to lose their sorption capacity over repeated cycles due to sintering at high temperatures. Herein, we present a demonstration of SESRT using A- and B-site doped Sr_1−xA’_xFe_1−yB’_yO_3−δ(A’ = Ba, Ca; B’ = Co) perovskites in a chemical looping scheme. We found that surface impregnation of 5–10 mol% Ni on the perovskite was effective in improving toluene conversion. However, upon cycling, the impregnated Ni tends to migrate into the bulk and lose activity. This prompted the adoption of a dual bed configuration using a pre-bed of NiO/γ–Al₂O₃catalyst upstream of the sorbent. A comparison is made between isothermal operation and a more traditional temperature-swing mode, where for the latter, an average sorption capacity of ∼38% was witnessed over five SESR cycles with H₂-rich product syngas evidenced by a ratio of H₂: CO_x> 4.0. XRD analysis of fresh and cycled samples of Sr_0.25Ba_0.75Fe_0.375Co_0.625O_3-δreveal that this material is an effective phase transition sorbent—capable of cyclically capturing and releasing CO₂without irreversible phase changes occurring. 

Abstract The structural and compositional flexibility of perovskite oxides and their complex yet tunable redox properties offer unique optimization opportunities for thermochemical energy storage (TCES). To improve the relatively inefficient and empirical‐based approaches, a high‐throughput combinatorial approach for accelerated development and optimization of perovskite oxides for TCES is reported here. Specifically, thermodynamic‐based screening criteria are applied to the high‐throughput density functional theory (DFT) simulation results of over 2000 A/B‐site doped SrFeO_3−δ. 61 promising TCES candidates are selected based on the DFT prediction. Of these, 45 materials with pure perovskite phases are thoroughly evaluated. The experimental results support the effectiveness of the high‐throughput approach in determining both the oxygen capacity and the oxidation enthalpy of the perovskite oxides. Many of the screened materials exhibit promising performance under practical operating conditions: Sr_0.875Ba_0.125FeO_3−δexhibits a chemical energy storage density of 85 kJ kg_ABO3⁻¹under an isobaric condition (with air) between 400 and 800 °C whereas Sr_0.125Ca_0.875Fe_0.25Mn_0.75O_3−δdemonstrates an energy density of 157 kJ kg_ABO3⁻¹between 400 °C/0.2 atm O₂and 1100 °C/0.01 atm O₂. An improved set of optimization criteria is also developed, based on a combination of DFT and experimental results, to improve the effectiveness for accelerated development of redox‐active perovskite oxides.