Regeneration of methane splitting catalysts by interfacial hydrogenation

• Type: Article in International Scientific Journal
• Date: 2024

Authors

Alves, L (Author) Other; Pereira, V (Author) Other; Delgado, S (Author) Other; Atashi, N (Author) Other; Dias, P. (Author) FEUP; Lagarteira, T (Author) Other; Prieto, G (Author) Other; Adélio Mendes (Author) FEUP

Journal

Title: Chemical Engineering Journal

Vol. 500

ISSN: 1385-8947

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 2 Citations

Other information

Authenticus ID: P-017-AHS

DOI: 10.1016/j.cej.2024.157046

Abstract (EN): Methane splitting, also known as decomposition or pyrolysis, has a unique potential to accelerate the transition from the current carbon-based economy towards the foreseen hydrogen economy. Low-temperature catalytic methane splitting systems are unavailable due to fast catalyst deactivation, caused by solid carbon that encapsulates the catalyst. Catalyst regeneration must be performed to reactivate the catalyst and achieve a long-term operational lifetime. This can be accomplished by cyclically refeeding a portion of the produced hydrogen back to the catalyst, which promotes the hydrogenation of carbon atoms, preferentially at the interface between carbon deposits and catalytic nanoparticles. Interfacial hydrogenation ideally breaks the bonds that connect carbon allotrope products to the metal catalyst, causing the former to detach, and freeing the catalytic metal surface for further reaction. In this work, a proof-of-concept of this technology is provided, showing the full regeneration of a bulk-type Ni catalyst during 22 cycles of methane splitting, at 550 degrees C and 1 bar. Furthermore, a commercial SiO2-Al2O3-supported Ni catalyst has been used to study the regenerability of a highly active nanostructured material by interfacial hydrogenation, using different reactor designs. It has been demonstrated that regeneration is beneficial to improve the stability of Ni-based systems, at the applied working conditions. Nevertheless, tip-grown carbon nanotubes were considered as a cause of permanent deactivation, which could not be solved by refeeding hydrogen into the system.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11