Appraisal of Ni Species Supported on Porous MgO during Ethanol Steam Reforming by XAS

Abstract

Operando time-resolved X-ray absorption spectroscopy (XAS) was used to determine nickel species supported on porous MgO during the ethanol steam reforming reaction. The Principal Component Analysis (PCA) of the nickel K-edge XAS spectra revealed Ni(OH) 2 , NiMgO, and metallic Ni during the activation and reaction of the catalysts. The Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) method for the timeresolved XAS spectra data permitted to calculate the concentration of species during the activation and reaction steps and to determine the formation of NiMgO and nickel reduction degree. The samples prepared with surfactants, Ni 10 MgO-F127 and Ni 10 MgO-P123, showed less nickel reduction (less than 30 %) but were more active and stable than the reference Ni 10 MgO catalyst, which reduced 52 %. It happened due to the smaller particle size and a larger specific area of the porous supports. The samples synthesized without Pluronic deactivated, and ethanol dehydrogenation became predominant instead of the ethanol steam reforming.

Recent Status in Catalyst Modification Strategies for Hydrogen Production from Ethanol Steam Reforming

“…The strong electrostatic interaction between Ni active phase and SiO 2 is conducive to form smaller Ni particle size and the enhancement of metal-support interaction, thus the Ni/SF-SEA exhibited higher catalytic activity and stability compared with Ni/SF catalysts prepared by impregnation and deposition precipitation methods. [115] The use of surfactant is a favorable et al [113,122] reported nano-crystalline MgO supported Ni catalyst prepared by using pluronic P123 and F127 as structure- [113] Reprinted with permission from Ref. [113] Copyright 2021 Elsevier.…”

“…The use of surfactant is a favorable strategy to realize stable dispersion of active components and formation of mesoporous structure. Recently, Possato et al [113,122] . reported nano‐crystalline MgO supported Ni catalyst prepared by using pluronic P123 and F127 as structure‐directing agent.…”