Tailoring lattice oxygen triggered NiO/Ca9Co12O28 catalysts for sorption-enhanced renewable hydrogen production.

Sorption-enhanced steam reforming of ethanol shows potential of supplying high-quality hydrogen with in situ CO 2 capture, but suffers from sorbent deactivation. This paper describers the design of functionalized x NiO/Ca 9 Co 12 O 28 materials, whose phases can be segregated once triggered by the lattice oxygen consumption via NiO/Ca 9 Co 12 O 28 -O2-→Ni-Co+CaO, thus acting as the catalytic sorbent. Their superiorities are demonstrated in: (i) low-temperature activation via lattice oxygen induction; (ii) recyclability via lattice oxygen replenishment; iii) high-quality hydrogen actuation via in situ CO 2 adsorption. Hydrogen concentration of 95.56 vol% and near-complete ethanol conversion can be achieved. Moreover, stability across 50 repeated cycles without obvious reduction in catalytic reforming and CO 2 adsorption is demonstrated. In situ XRD studies demonstrate the formation of the Ni-Co alloy and the reorganization of the catalytic sorbent. The adsorption energies of ethanol on the surface of Ni(111), Co(111), and Ni-Co(111) were studied by DFT calculations, reaffirming the higher catalytic activity of Ni-Co alloys. [Display omitted] • A series of lattice oxygen triggered NiO/Ca 9 Co 12 O 28 catalysts were fabricated. • Phase segregation and reformation of the catalyst can be proceeded via switch-on-off looping. • Hydrogen concentration of 95.56 vol% and near 100% ethanol conversion can be achieved. • The promotional role of Ni doping on catalytic activity and CO 2 uptake capacity was identified. • DFT results revealed the enhancement of Ni-Co alloy on ethanol activation and CO 2 adsorption. [ABSTRACT FROM AUTHOR]