Abstract
Sorption-enhanced steam reforming of ethanol shows potential of supplying high-quality hydrogen with in situ CO2 capture, but suffers from sorbent deactivation. This paper describers the design of functionalized xNiO/CagCo_(12)O_(28) materials, whose phases can be segregated once triggered by the lattice oxygen consumption via NiO/Ca9Co_(12)O_(28)-O~(2-)→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; hi) high-quality hydrogen actuation via in situ CO2 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 CO2 adsorption is demonstrated. In situ XKD 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(III), Co(III), and Ni-Co(III) were studied by DFT calculations, reaffirming the higher catalytic activity of Ni-Co alloys.
NSTL