Carbon Nanosphere-Encapsulated Fe Core–Shell Structures for Catalytic CO₂ Hydrogenation

Abstract

We synthesized a unique carbon nanosphere (CNS)encapsulated Fe core−shell catalyst (CNS−Fe) for CO 2 hydrogenation. The synthesized CNS−Fe catalyst exhibited a core−shell structure with a core of ca. 40 nm containing iron species and a shell thickness of ca. 10 nm composed of mainly graphitic carbon. X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and thermogravimetric analysis were used to characterize the fresh and spent CNS−Fe catalysts and reveal a mixture of Fe 3 O 4 , metallic Fe, and Fe 5 C 2 in the core and graphitic carbon as the shell with defect sites. Hydrogen temperature-programmed reduction, X-ray absorption near-edge structure, and extended X-ray absorption fine structure for the fresh CNS−Fe confirmed the composition of the iron species encapsulated in the CNS. The catalytic performance of CNS−Fe was investigated at ambient pressure for CO 2 hydrogenation with hydrocarbons (CH 4 , C 2 −C 4 = , C 2 −C 4 0 ), and CO was observed as the main product.

Harnessing the Synergy of Fe and Co with Carbon Nanofibers for Enhanced CO2 Hydrogenation Performance

“…We further noted that the intensity of the (110) Fe and (510) Fe 5 C 2 peaks was amplified with rising temperatures, indicative of particle growth (Figure A). Concurrently, the increasingly distinct peak at 24.3° confirms the progressive graphitization of carbon beyond 850 °C, specifically representing the (002) plane of graphitized carbon …”

“…All of these catalyst variants were subjected to a reduction and activation process at 350 °C for 2 h in a 50% H 2 stream. This specific set of activation conditions was meticulously chosen based on insights garnered from our previous hydrogen temperature-programmed reduction (H 2 -TPR) studies . By implementing these conditions, we strategically facilitated the partial reduction of surface functional groups present on the carbon material, a step that plays a pivotal role in amplifying the catalytic activity of the system.…”

Nanostructured carbon electrocatalysts for clean energy conversion and storage: A mini review on the structural impact

“…Due to special electronic properties and space limitations, the metal inside the core-shell structure has more catalytic activity than the metal deposited on the surface. For example, the core-shell structure prepared by Weber et al has a graphite-like shell with abundant defect sites, which showed high catalytic performance in HER (Weber et al, 2022).…”

The Effect of Mn, Al Doping on the CO2 Hydrogenation Performance of CaCO3‐Supported Fe‐Based Catalysts

“…[15] The CCH route comprises reverse water gas reaction (RWGS) and Fischer-Tropsch synthesis. [20][21][22] These two reactions use Fe 3 O 4 and FeC x as active catalytic sites, respectively. Although they are two different active sites, both are compounds of Fe, and they can be generated in situ simultaneously after activation.…”

“…This route is friendly for product selectivity, but its CO 2 conversion is generally low [15] . The CCH route comprises reverse water gas reaction (RWGS) and Fischer‐Tropsch synthesis [20–22] . These two reactions use Fe 3 O 4 and FeC x as active catalytic sites, respectively.…”