Synthesis of Ni-based catalysts by hexamethylenetetramine-nitrates solution combustion method for co-production of hydrogen and nanofibrous carbon from methane

Kuvshinov, D. G.; Kurmashov, P. B.; Bannov, A. G.; Popov, M. V.; Kuvshinov, G. G.

Abstract

It was shown that hexamethylenetetramine (HMT)is a new effective fuel for single-step solutions combustion synthesis (SCS)of supported Ni catalysts for methane decomposition into hydrogen and nanofibrous carbon. Several generalized chemical equations reflecting different ideas about combustion of the HMT−Ni(NO 3 ) 2 −Cu(NO 3 ) 2 −Al(NO 3 ) 3 −H 2 O system have been derived. On the basis of those equations the adiabatic combustion temperature (T ad )and the amount of gaseous products (n g )have been calculated depending on the ignition temperature (T 1 ), water content (m), excess fuel coefficient (φ), and the composition of the obtained solid product. The calculations have shown that T ad , depending on m and φ, changes from hundreds to thousands of degrees Kelvin. Increase of Al 2 O 3 content in the catalyst up to 0.6 increases T ad by hundreds of degrees, and that increase of the Ni:NiO ratio up to 0.5 lowers T ad by tens of degrees. Three samples of the supported unreduced 0.97NiO/0.03Al 2 O 3 catalyst were successfully prepared with the help of the SCS method using HMT as the fuel at φ=0.7. Those samples, obtained at reaction mixture preliminary heating rates V = 1, 10, 15 K/min were characterised using XRD, TEM, and SEM, and further tested in a pure methane decomposition reaction (100 L CH4 /h/g cat , 823К, 1 bar). Nanoparticles of metal Ni were found in the SCS products, in contrast to cases when other types of fuel were used with φ

Citation

Kuvshinov, D. G., Kurmashov, P. B., Bannov, A. G., Popov, M. V., & Kuvshinov, G. G. (2019). Synthesis of Ni-based catalysts by hexamethylenetetramine-nitrates solution combustion method for co-production of hydrogen and nanofibrous carbon from methane. International Journal of Hydrogen Energy, 44(31), 16271-16286. https://doi.org/10.1016/j.ijhydene.2019.04.179

• Journal Article Type: Article
• Acceptance Date: Apr 17, 2019
• Online Publication Date: May 18, 2019
• Publication Date: Jun 21, 2019
• Deposit Date: Jun 11, 2019
• Publicly Available Date: May 19, 2020
• Journal: International Journal of Hydrogen Energy
• Print ISSN: 0360-3199
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 44
• Issue: 31
• Pages: 16271-16286
• DOI: https://doi.org/10.1016/j.ijhydene.2019.04.179
• Keywords: Nickel-based catalyst; Solution combustion synthesis; Hexamethylenetetramine; Adiabatic combustion; Methane decomposition; Hydrogen and carbon nanofibers production
• Public URL: https://hull-repository.worktribe.com/output/1974410
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S036031991931612X?via%3Dihub
• Additional Information: ©2019, Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/