POSTECH researchers have unraveled a potential new zeolite expected to be a milestone for the oil refining and petrochemical industries.
(Top left) SBT (blue) and SBS (red) framework types. (Bottom left) Cs-corrected STEM-ADF image of PST-2, a SBS/SBT intergrowth zeolite. (Right) Light olefins (ethylene and propylene) yield and propylene/ethylene ratio in diesel cracking over H-PST-32, H-PST-2, H-USY, and H-beta catalysts. Image Credit: POSTECH.
The study findings were published on July 2nd, 2021, in the journal Science.
The research team headed by Suk Bong Hong, a professor in the Division of Environmental Science and Engineering at POSTECH, used the “multiple inorganic cation” and the “charge density mismatch” synthetic approaches to produce two thermally stable three-dimensional (3D) large-pore (12-ring) zeolites — PST-32 (POSTECH No. 32) and PST-2, the hypothetical SBS/SBT intergrowth structure, respectively.
The researchers determined the structure of the zeolites using powder X-ray diffraction data at the Pohang Accelerator Lab and electron microscopy analysis at the Instituto de Nanociencia y Materiales de Aragon (INMA). Dr. Hwajun Lee of POSTECH and Dr. Jiho Shin of the Petrochemical Catalyst Research Center of the Korea Research Institute of Chemical Technology are the co-first authors of this study.
Zeolites can be described as crystalline microporous aluminosilicate materials that exhibit uniform and well-characterized pore structures that provide an extensive range of commercial applications in catalysis and separation, thanks to their structural and chemical stability.
Zeolite Y, with a cage-based large-pore (12-ring) structure, is an indispensable catalyst in the petrochemical and oil refining processes that generate many kinds of chemical products from crude oil. Zeolite Y-based catalysts are used to make around 40% of the world’s crude oil production into essential products suited for daily life, like gasoline.
Although the recently created PST-32 and PST-2 are structurally similar to zeolite Y, they contain super-cages of different sizes and shapes and exhibit excellent thermal stability. These zeolites also exhibit higher catalytic activity compared to zeolite Y in the reaction to synthesize the chemicals ethylene and propylene, which are fundamental raw materials produced by decomposing diesel, which is losing value as a fuel source.
Considering the fact that zeolite Y-based catalysts account for 10% of the global catalyst market, which is more than 10 billion USD, Science seems to have deemed PST-32 and PST-2 as game-changers that can disrupt the catalyst market, in addition to their scholarly significance.
Suk Bong Hong, Professor, Division of Environmental Science and Engineering, Pohang University of Science and Technology
The research was financially supported by the National Creative Research Initiative Program (2012R1A3A2048833) through the National Research Foundation.
Journal Reference:
Lee, H., et al. (2021) Synthesis of thermally stable SBT and SBS/SBT intergrowth zeolites. Science. doi.org/10.1126/science.abi7208.