Polyu Discovers Two Nano Extra-Large-Pore Zeolite Catalysts Using Advanced Materials Development Strategy
Zeolites with crystalline porous structures are the core catalysts in petroleum refining and fine chemical industries. However, current industrial zeolites are large crystal bulk and have small micropores, limiting their applications for decades in the efficient processing of large molecules. Nano extra-large-pore zeolites are the ideal solution to this end but are rather challenging to develop. Now, researchers of The Hong Kong Polytechnic University (PolyU) have pioneered an effective strategy to accelerate the discovery of such zeolites, advancing not only fundamental zeolite sciences but also industrial catalysis.
The effective phase identification and structure determination pose a major obstacle to the development of all new materials. Dr. LIN Cong, Research Assistant Professor of the Department of Applied Biology and Chemical Technology at PolyU, and his research team worked with collaborators from Nanjing University and Research Institute of Petroleum Processing at SINOPEC, and have developed a universally feasible strategy to overcome this critical challenge. By integrating state-of-the-art microcrystal electron diffraction (MicroED) with combinatorial chemistry, they achieved high-throughput screening and efficient synthesis optimization to accelerate the development of nano extra-large-pore zeolites. The findings have been published in the international journal Science.
The researchers first tested a wide range of compositions for zeolite synthesis and characterized the resultants in parallel using a combinatorial approach. Then, with high-throughput MicroED, they completed rapid phase elucidation and structure determination within multiphase polycrystalline samples, enabling efficient screening of new zeolites. Based on the results, synthetic parameters were pertinently optimized towards pure zeolites. Benefiting from this powerful strategy, two nano extra-large-pore zeolites were developed.
The two new zeolites both exhibit nano morphologies, i.e., ultra-thin nanosheets or nanorods, which significantly shortens the diffusion lengths of large molecules and improves accessibility to active catalytic sites. More importantly, they feature complex, three-dimensional, and interconnected pore structures, with the main extra-large 22-membered-ring pores far exceeding most existing zeolites in pore sizes, offering ample space to further the diffusion and conversion of large molecules.
In fluid catalytic cracking of heavy oil composed of large molecules, the two zeolites demonstrate superior performance over industrial counterparts, with higher heavy-oil conversion, higher yields of high-value fuels (i.e., gasoline and diesel, accounting for over 50% of total products), and less coking. These catalytic capabilities underscore the potential of these two zeolites as efficient heterogeneous catalysts.
This study marks a significant breakthrough in zeolite sciences, helping overcome the long-standing barriers in zeolite development while unlocking the potential of nano extra-large-pore zeolites in industrial catalysis. The proposed strategy with advanced MicroED also opens up new avenues for the development and in-depth structural understanding of new materials.
Dr. Lin said, “Our work will motivate continued innovation and advancement in new materials discovery, not limited to zeolites. We are also confident that leveraging our effective strategy, more nano extra-large-pore zeolites characterized by complex structures and catalytic activity will be rapidly developed.”
Moving forward, the research team will continue working on the fundamental explorations of new zeolites and their potential in catalysis. Furthermore, with the extensive networks and research strengths of the PolyU-Daya Bay Technology and Innovation Research Institute, the team will also seek collaborations with domestic petrochemical industries to accelerate the commercialization of these new zeolites.
