Catalytic Methane Decomposition to Hydrogen over a Surface-Protected Core-Shell Ni@SiO2 Catalyst

Methane decomposition is a promising method to obtain COx-free hydrogen. The main difficulty of this process is that the produced carbon would deposit on the active phase of the catalyst, leading to catalyst deactivation. In this study, a core-shell-structured composite catalyst comprising highly active Ni nanoparticles (NP) as core and mesoporous silica as shell is introduced. The silica shells were synthesized by using cetyltrimethylammonium bromide as template and tetraethyl orthosilicate as precursor. Ni NP and Ni@SiO2 were examined as catalysts for hydrogen production by methane decomposition at different temperatures and gas hourly space velocities. The results show that the core-shell catalyst exhibited much better stability in methane decomposition than Ni NP without silica shell and a traditional supported catalyst.