Understanding relationship of sepiolite structure tailoring and the catalytic behaviors in glycerol steam reforming over Co/sepiolite derived Co-phyllosilicate catalyst

Bio-glycerol Steam reforming over green and economical Co/sepiolite (SEP) catalysts was a promising strategy to hydrogen production. The activation pretreatment of SEP played a vital role for boosting catalytic behavior of Co/SEP. This work originally explored a full activation of SEP by molten NaOH for tailoring the physicochemical properties of Co-based catalysts prepared by urea precipitation method. Differing from the acid pickling/calcination and molten NaNO3 activation, the molten NaOH treatment enhanced surface area of SEP by desilicication/dealumination effect and further improved the exposure of framework Si and its surface 'reactivity'. According to the characterization results of N-2 adsorption-desorption, XRD, TEM, H-2-TPR, CO/CO2-TPD and XPS, it was found that the feathered Co-phyllosilicate formed on Co/SEP-NaOH catalyst, which enhanced the metal-support interaction, surface area and basic/metallic sites. In contrast, the molten NaNO3 treatment facilitated the transformation of SEP into loughlinite and it was adverse to metal dispersion. Therefore, Co/SEP-NaOH catalyst possessed the highest conversion (92%) and H-2 yield (68%) during the activity test at 600 degrees C and the superior resistance to amorphous coke. Additionally, DFT analysis was introduced to simulate the process of glycerol adsorption and decomposition and demonstrated the Co-CoO interface as the primary reaction sites for the catalytic process. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Treatment with molten NaOH can enhance the surface area of SEP and improve its surface reactivity, leading to better catalytic performance in bio-glycerol steam reforming.