Promotional role of NiCu alloy in catalytic performance and carbon properties for CO₂-free H₂ production from thermocatalytic decomposition of methane

Abstract

Thermocatalytic decomposition (TCD) of methane produces CO2-free hydrogen and valuable co-product, solid carbon. In this study, a series of Ni-Cu/CNT catalysts, prepared with varying Ni/Cu metal ratios and synthesis methods,...

Balancing act: influence of Cu content in NiCu/C catalysts for methane decomposition

“…Several explanations for the influence of Cu are reported in literature, such as improved methane adsorption, 15,17,23,26 promoting carbon diffusion by an increased lattice constant, 23 or stabilization of larger particles 27 which provides more sustainable growth. 27,38 Also, a dilution effect is mentioned: by the presence of inactive Cu at the catalyst surface, fewer active surface sites are available. Consequently, the reaction rate becomes slower.…”

“…9,36,37 Xu et al reported stabilization of larger particles as a cause for the improved activity 27 since they facilitate a more steady growth. 27,38 Turaeva et al noticed that the electronic structure, especially the position of the top of the d-band with respect to the Fermi level is of key importance for nanostructure growth, 9 which is changed by alloying Ni with Cu. 39 To understand overall macroscopic observations on the influence of catalyst composition on catalytic performance, it is essential to also have a closer look at the individual particles.…”

“…Especially, bimetallic Ni-Cu catalysts have received much attention. 10,14,15,[23][24][25][26][27][28][29][30][31][32][33] NiCu catalysts usually provide higher activities and longer lifetimes than Ni catalysts and their use increases the optimal reaction temperaturewhich allows for higher conversions. 29,31 However, the exact role of Cu and why it is so beneficial is not clear yet, especially not its influence on the individual nanoparticle level.…”

“…23 Carbon solubility might be important and is greatly impacted by changes in the electronic structure. 9,36,37 Xu et al reported stabilization of larger particles as a cause for the improved activity 27 since they facilitate a more steady growth. 27,38 Turaeva et al noticed that the electronic structure, especially the position of the top of the d-band with respect to the Fermi level is of key importance for nanostructure growth, 9 which is changed by alloying Ni with Cu.…”

Synthesis of Ni-Cu-CNF Composite Materials via Carbon Erosion of Ni-Cu Bulk Alloys Prepared by Mechanochemical Alloying

“…However, due to the high temperatures required for the decomposition of hydrocarbons, the process is complicated by the sintering of metal particles and coking (deposition of non-structured carbon). Ultimately, it leads to the deactivation of the catalyst and a significant loss in process efficiency [48][49][50]. Therefore, the development of new approaches to the synthesis of active and stable Ni-Cu catalysts remains an actual problem.…”