Infiltrate Mesoporous Silica-Aluminosilicate Structure Improves Hydrogen Production via Methane Decomposition over a Nickel-Based Catalyst

Abstract

A potential nickel-supported infiltrate mesoporous silica-aluminosilicate (Ni/SAS) catalyst was developed for improving hydrogen production through methane decomposition reaction. Infiltrate mesoporous silica-aluminosilicate supports with different Si/Al ratios (25, 50, and 100) were synthesized through a sol–gel method, then nickel metal was loaded on the support using an incipient impregnation method. All SAS­(x) supports revealed a bimodal mesoporous structure with pore sizes at 2.7 and 3.9 nm. The aluminum favorably incorporated into the silica framework in the tetrahedral-coordinated position as [AlO4]5– to form an aluminosilicate framework in the structure of SAS(50). The active nickel area of Ni/SAS­(x) catalysts was 1.30–2.27 times higher than that of the Ni/MCM-41 catalyst. Using the Ni/SAS­(x) catalyst in the cracking reaction gave a higher H2 yield than using a Ni-supported silica catalyst. In particular, the H2 yield of the Ni/SAS(50) catalyst was 1.45, 1.11, and 1.29 times higher than that of the Ni/MCM-41 catalyst at 500, 550, and 600 °C, respectively. This performance could be attributed to a promotional effect of the infiltrate aluminosilicate framework as well as the moderate surface acidity, which enhanced the Ni dispersion and interaction between Ni and the SAS support, resulting in the multi-walled carbon nanotube formation via a tip-growth mechanism. Consequently, the active surface of the Ni/SAS(50) catalyst remained constant throughout the methane decomposition reaction.

Effect of Calcination Temperature on Cu-Modified Ni Catalysts Supported on Mesocellular Silica for Methane Decomposition

“…Most CNFs formed on the NiCu/MS(500) and NiCu/MS(800) catalysts through the base-growth mechanism, where the active Ni–Cu metals were partially covered by CNFs, , arising from a strong interaction between Ni–Cu and the MS support (in accordance with the H 2 -TPR results). Therefore, the activity and stability of both catalysts were deactivated during the reaction.…”

“…Notably, the activity and stability of a Ni-based catalyst can be improved by selecting suitable supports and promoters because these supports have a substantial role in the catalytic reaction as they help to increase the metal catalyst dispersion and therefore, improve the activity of catalysts while minimizing the catalyst sintering. Many types of materials such as silica − (SiO 2 ), alumina (Al 2 O 3 ), zeolite, and metal oxides, ,− such as ZrO 2 , MgO, and TiO 2 , have been used as catalyst supports for catalytic methane decomposition. SiO 2 material has been widely used as support because the interaction between metal and silica support is quite weak compared to the other supports in which the metal–support interaction is one of the factors determining the activity and lifetime of the catalyst. ,, Our previous work found that the SiO 2 structure support directly affected activity and stability in the methane decomposition reaction.…”

“…Many types of materials such as silica − (SiO 2 ), alumina (Al 2 O 3 ), zeolite, and metal oxides, ,− such as ZrO 2 , MgO, and TiO 2 , have been used as catalyst supports for catalytic methane decomposition. SiO 2 material has been widely used as support because the interaction between metal and silica support is quite weak compared to the other supports in which the metal–support interaction is one of the factors determining the activity and lifetime of the catalyst. ,, Our previous work found that the SiO 2 structure support directly affected activity and stability in the methane decomposition reaction. Ni supported on bimodal porous silica with mesopore and macropore structures produced higher activity and stability than that of Ni supported on monomodal porous silica with straight and sinusoidal mesopore because a larger pore size of the support enhanced the diffusion of the reactant gas during the reaction.…”

Catalytic methane decomposition to hydrogen and carbon over hydrotalcite‐derivative composition‐uniform and sintering‐resistant Ni‐Fe / Al 2 O 3 alloy catalysts

“…However, the problem is that the active metal particles are easily encapsulated with carbon, causing a rapid deactivation of the catalyst. Therefore, many studies have been devoted to enhancing the catalyst performance 12‐20 …”

“…Therefore, many studies have been devoted to enhancing the catalyst performance. [12][13][14][15][16][17][18][19][20] It has been indicated that the addition of a second metal to the nickel catalyst can improve the catalytic performance of CDM. 21 In this regard, Cu-promoted Ni catalysts have been widely investigated and demonstrated to enhance the catalytic life and carbon yield in CDM.…”