Study of K-Li2ZrO3 based sorbents as potential precursors of hybrid materials for the sorption enhanced steam reforming of ethanol

Abstract

In this work, a series of CO2 sorbents based on K-Li2ZrO3 were synthesized with Li/Zr nominal ratios: 1.72, 1.57, 1.45, 1.35 and 1.18. t-Li2ZrO3 along with t-ZrO2 and m-ZrO2 phases were observed by XRD, confirming the generation of the active phase for the CO2 sorption. The CO2 capture properties of the samples were evaluated with low CO2 concentration (15%), under dry and wet conditions. All the sorbents improved their CO2 capture kinetics in the presence of water, this effect being more marked in the sample with nominal Li/Zr=1.18. This sorbent was used as starting material for the synthesis of a potential hybrid material for the SESRE reaction based on Ni and K-Li2ZrO3, which was labeled as NiKLiZr. The presence of Ni would modify the adsorption-reaction pattern, reducing the capture kinetics. However, the hybrid material presented good ethanol conversion and high H2 yielding, even after eight hours of reaction. The good catalytic properties and high CO2 capture efficiency motivated the exploration of this solid in the sorption-enhanced steam reforming of ethanol, including the investigation of the transient period and early reaction stages.