Overview and Industrial Assessment of Synthesis Strategies towards Zeolites with Mesopores

Abstract

International audienceWith the necessity for the refining industry to treat heavier feedstocks, there is a clear demand for improved zeolite materials displaying better accessible surface areas and higher pore volumes in order to capitalize on their effectiveness. To this end, over the last decade, there has been an intensification of research on the exploration of new routes to synthesize zeolite materials combining micropores with mesopores. Different synthesis strategies are used for their preparation (i.e., by structure breaking or so-called 'destructive' pathways, or structure building or so-called 'constructive' synthesis pathways). This Review discusses the variety of current synthesis strategies, while emphasizing the strengths and weaknesses of the different routes regarding material characteristics; health, safety, and environment aspects; and synthesis costs

Improved THETA-1 for Light Olefins Oligomerization to Diesel: Influence of Textural and Acidic Properties

“…One procedure for generation of mesopores in high silica zeolites is by controlled desilication in alkaline media [26][27][28][29]. In this case the mesopore formation results from preferential dissolution of Si from the zeolite framework and the Al content of the parent zeolite is known to affect the effectiveness of the treatment [28].…”

Hierarchy concepts: classification and preparation strategies for zeolite containing materials with hierarchical porosity

“…This feature has been utilised to tune (reduce) the catalytic activity of different zeolitic materials, the most prominent being zeolite Y. 88 Dealumination by steaming may also result in extraframework aluminium. These extra-framework species potentially form Lewis acid sites, which can be advantageous in some catalytic reactions.…”

Hierarchically Nanoporous Zeolites and Their Heterogeneous Catalysis: Current Status and Future Perspectives

“…Since the mesopores are generated by the extraction of framework Al that was responsible for zeolite acidity, the dealumination reduces the total number of acid sites. Contrary to the dealumination, mesopores can also be generated by post-desilication method [14,25]. In this route, the mesopores can be produced by base treatment that can leach out the Si species from the zeolite framework, which makes mesopores that are interconnected each other and accessible from the external surface of the zeolite crystal [26,27].…”