Operando Spectroscopic Study of Dynamic Structure of Iron Oxide Catalysts during CO₂ Hydrogenation

Abstract

Understanding of dynamic structure of active sites is of paramounti mportance for rational design of industrialc atalysts. This work revealed the structure evolution of iron active phases for CO 2 hydrogenation over iron-based catalysts. With a combination of operando Ramans pectroscopy and X-ray Diffraction coupled with online gas chromatography,t he panoramic structure evolution of iron oxides (a-Fe 2 O 3 and g-Fe 2 O 3 ) during activation and CO 2 hydrogenation were elaborated, that is, a-

Highly Selective Olefin Production from CO2 Hydrogenation on Iron Catalysts: A Subtle Synergy between Manganese and Sodium Additives

“…X‐ray diffraction (XRD) profiles of the oxide forms of these catalysts (Figure 1 a; obtained from calcination of the corresponding hydroxy‐carbonate precursors at 350 °C) only exhibit diffraction peaks belonging to the α‐Fe 2 O 3 phase (e.g. 2 θ =33.1°, 35.6°, and 40.6°) [5a] . The absence of XRD patterns relevant to Na 2 O or MnO x phases indicates high dispersion of these oxide components in the α‐Fe 2 O 3 bulk matrix, consistent with the uniform distribution of these three metal elements in the FeMnNa catalysts as reflected from the element mapping of their scanning transmission electron microscopy (STEM) images (Figure 1 b–e).…”

Unravelling the metal–support interactions in χ-Fe5C2/MgO catalysts for olefin synthesis directly from syngas

“…3.1 Structure of Fe 2 O 3 /MgO STO has been recognized as a highly phase-sensitive 30,31 and size-dependent 32,33 reaction. In this study, the phase and size of iron species for all the as-prepared precursors are controlled at the same level to rule out the effects of the phase and size on the catalytic performance.…”

Recent advances on the reduction of CO2 to important C2+ oxygenated chemicals and fuels

“…A C C E P T E D M A N U S C R I P T Figure 14. Scheme of structure-performance relationship of α-Fe 2 O 3 and γ-Fe 2 O 3 catalysts for CO 2 hydrogenation during activation and reaction processes [88].…”