Promoting Effects of Copper and Iron on Ni/MSN Catalysts for Methane Decomposition

Abstract

Copper and iron-based bimetallic nickel catalysts supported on Mesostructured Silica Nanoparticles (MSNs) with compositions of 50% Ni–5% Cu/MSN and 50% Ni–5% Fe/MSN were prepared using an impregnation method, and they were compared with a monometallic 50% Ni–MSN catalyst for their activity and stability in methane decomposition reaction. The influence of promoters, such as Cu and Fe, at different reaction temperatures (700 °C, 800 °C and 900 °C) was investigated. The results revealed that the Cu and Fe-promoted catalysts significantly increased the hydrogen yield in methane decomposition compared with the unpromoted catalyst. This could be attributed to the formation of Ni–Cu and Ni–Fe bimetallic alloys in the catalysts, respectively, and this favored the stability of the catalysts. With increasing reaction temperature, the hydrogen yield also increased. However, the hydrogen yield and the lifetime of the nickel catalyst were enhanced upon the addition of iron compared to copper at all the reaction temperatures. The analysis conducted over the spent catalysts validated the formation of multi-walled carbon nanotubes with a bamboo-like internal channel over the catalysts along with a high crystallinity and graphitization degree of the carbon produced.

Potassium-promoted Ru-MCM-41 catalyst via in situ loading for effective low-temperature ammonia decomposition

“…4a, the isotherms of all three samples belong to type IV. 45–47 The hysteresis loop of the MCM-41 material is of type H 1 , which is a characteristic of mesoporous materials. 65,66 The 4Ru-MCM-41 and K-4Ru-MCM-41 materials have hysteresis loops of type H 3 , 8 indicating that the catalysts contain mesoporous architectures.…”

“…42–44 Among these materials, MCM-41 has been widely studied due to its two-dimensional structure with interconnected pores. 45 Compared with materials such as MSN 46,47 and SBA-15, 48,49 MCM-41 has the advantages of high thermal stability, large pore size and high specific surface area, 50 which makes MCM-41 one of the best carrier materials.…”

Insights into Reaction Mechanisms in Liquid Metals from Density Functional Theory: CH4 Pyrolysis in BiNiX (X = Cu, Al) Molten Metals as a Case Study

“…Several strategies have been developed to address the coking problem, to control the morphology of the carbon product, and to improve the reactivity of the Ni component. Some of these methods include the careful design of the support material to increase the dispersion of the active metal, , modifying the composition of the catalytic alloys, and employing promoters . Another effective solution to these issues is the use of molten metals and molten salts, which was proposed at the end of the 1990s.…”

“…Some of these methods include the careful design of the support material to increase the dispersion of the active metal, 21,22 modifying the composition of the catalytic alloys, 23 and employing promoters. 24 Another effective solution to these issues is the use of molten metals and molten salts, which was proposed at the end of the 1990s. One of the earliest designs, developed by Steinberg, 25 utilizes molten tin or copper.…”