Synthesis of graphene-encapsulated Fe3C/Fe catalyst supported on Sporopollenin exine capsules, and its use for the reverse water gas shift reaction

Malik, Waqas; Tafoya, Jorge Pavel Victoria; Doszczeczko, Szymon; Jorge Sobrido, Ana Belen; Skoulou, Vasiliki; Boa, Andrew N.; Zhang, Qi; Ramirez Reina, Tomas; Volpe, Roberto

Abstract

Bioderived materials have emerged as sustainable catalyst supports for several heterogeneous reactions owing to their naturally occurring hierarchal pore size distribution, high surface area, and thermal and chemical stability. We utilize sporopollenin exine capsules (SpECs), a carbon-rich byproduct of pollen grains, composed primarily of polymerized and cross-linked lipids, to synthesize carbon-encapsulated iron nanoparticles via evaporative precipitation and pyrolytic treatments. The composition and morphology of the macroparticles were influenced by the precursor iron acetate concentration. Most significantly, the formation of crystalline phases (Fe3C, α-Fe, and graphite) detected via X-ray diffraction spectroscopy showed a critical dependence on iron loading. Significantly, the characteristic morphology and structure of the SpECs were largely preserved after high-temperature pyrolysis. Analysis of Brunauer–Emmett–Teller surface area, the D and G bands from Raman spectroscopy, and the relative ratio of the C═C to C–C bonding from high-resolution X-ray photoelectron spectroscopy suggests that porosity, surface area, and degree of graphitization were easily tuned by varying the Fe loading. A mechanism for the formation of crystalline phases and meso-porosity during the pyrolysis process is also proposed. SpEC-Fe10% proved to be highly active and selective for the reverse water–gas shift reaction at high temperatures (>600 °C).

Citation

Malik, W., Tafoya, J. . P. V., Doszczeczko, S., Jorge Sobrido, A. B., Skoulou, V., Boa, A. N., Zhang, Q., Ramirez Reina, T., & Volpe, R. (in press). Synthesis of graphene-encapsulated Fe3C/Fe catalyst supported on Sporopollenin exine capsules, and its use for the reverse water gas shift reaction. ACS Sustainable Chemistry and Engineering,

• Journal Article Type: Article
• Acceptance Date: Sep 28, 2023
• Online Publication Date: Oct 21, 2023
• Deposit Date: Oct 21, 2023
• Publicly Available Date: Oct 24, 2023
• Journal: ACS Sustainable Chemistry & Engineering
• Print ISSN: 2168-0485
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Keywords: Sporopollenin; Iron; Graphitization; Catalyst support and pyrolysis
• Public URL: https://hull-repository.worktribe.com/output/4100666