Thermochemical hydrogen production using Rh/CeO2/g-Al2O3 catalyst by steam reforming of ethanol and water splitting in a packed bed reactor

This study is focused on investigating the dual performance of Rh/CeO2/g-Al2O3 catalyst for steam reforming of ethanol (SRE) and thermochemical water splitting (TCWS) using a packed bed reactor. The catalyst is designed to be thermally stable containing an active phase of Rh and the redox component of CeO2 for oxygen exchange, supported on g-Al2O3. The catalyst has been characterised by SEM, XRD, BET, TPR, TPD, XPS and TGA before testing in the reactor. The optimal temperature for SRE reaction over this catalyst is between 700 degrees C and 800 degrees C to produce high concentrations of hydrogen (-60%), and low CO and CH4. The selectivity towards CO and CH4 is higher at low temperatures and drops with rise in reaction temperature. Further, Rh/CeO2/g-Al2O3 is found to be active for TCWS at relatively low temperatures (<= 1200 degrees C). At temperatures as low as 800 degrees C, this catalyst is especially found suitable for multiple redox cycles, producing a total of 48.9 mmol/gcat in four redox cycles. The catalyst can be employed for large number of redox cycles when the reactor is operated at lower temperatures. Finally, the reaction pathways have been proposed for both SRE and TCWS on Rh/CeO2/g-Al2O3 catalyst. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study focuses on the dual performance of Rh/CeO2/g-Al2O3 catalyst in steam reforming of ethanol (SRE) and thermochemical water splitting (TCWS). The catalyst shows optimal temperature range for high hydrogen production and higher selectivity towards CO and CH4 at low temperatures, and it is also active for TCWS at relatively low temperatures. The proposed reaction pathways for both SRE and TCWS on this catalyst have been presented in the study.