Dry reforming of methane (DRM) is one promising approach to converting methane and carbon dioxide into chemical feedstock or syngas. However, DRM needs a stable and highly active catalyst for its commercialization. Metal-supported zeolites are widely used for this purpose, due to their microporous structure and chemical stability.
In particular, certain aluminosilicate zeolites with two-dimensional (2D) structures are already established as effective catalysts. However, their synthesis involves a fairly complex and time-consuming series of steps, limiting their widespread commercialization.
Now, researchers from South Korea report the single-step preparation of a new DRM catalyst—a 2D nickel silicate molecular sieve with delaminated MWW layers (Ni-DML) by the simple hydrothermal conversion of a borosilicate MWW precursor with nickel nitrate solution. A paper on their work is published in Applied Catalysis B: Environmental.
The novel synthesis approach involved a simple hydrothermal treatment of a borosilicate precursor with a nickel-containing solution for a period of up to four days at relatively mild temperatures.
Min et al.
The result was a delaminated 2D material framework with active nickel centers that acted as a molecular sieve.
Molecular sieves with highly dispersed nickel species are attractive catalysts for DRM because they allow for the easy molecular diffusion of the relevant gases and are resistant to deactivation caused by coke deposition.— Professor Min Bum Park of Incheon National University, co-corresponding author
The team then characterized the new catalyst and tested for its conversion efficiency and stability in DRM. The results were promising. Ni-DML exhibited extremely high conversions of CH4 and CO2 as well as an extraordinary stability, maintaining its activity for 10 days on stream due to the in-situ formation of metallic nickel clusters from the framework species.
Additionally, it did not require pretreatment steps, such as air calcination and hydrogen reduction.
Hyung-Ki Min, Sungjoon Kweon, Young Woo Kim, Hyejin An, Donghui Jo, Eun Duck Park, Chae-Ho Shin, Min Bum Park (2021) “Atomically dispersed nickel species in a two-dimensional molecular sieve: Origin of high activity and stability in dry reforming of methane,” Applied Catalysis B: Environmental, Volume 298, doi: 10.1016/j.apcatb.2021.120627