Narrowing the mesopore size distribution in hierarchical TS-1 zeolite by surfactant-assisted reorganization

Synthesis of nanostructured catalysts by surfactant-templating of large-pore zeolites

“…2,7 In recent years, a number of strategies have been introduced in the eld of the synthesis of well-dened hierarchical zeolites containing micro-, meso-and macro-pores, such as the so-called bottom-up and top-down approaches. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] These approaches for improving the accessibility of active sites and transport efficiency rely upon the presence of a hierarchy of pores in the zeolite crystals, which are referred to as mesostructured or hierarchical zeolites. The bottom-up procedure is based on employing either hard or so templates, such as carbon nanotubes, polymers, and organic structure directing agents to generate secondary mesopores in the range 2-50 nm.…”

Recent Advances in synthesis and Application of Hierarchical Zeolite

“…Mesoporosity can be effectively introduced into zeolitic structure using mild conditions (e.g., dilute Na OH solution, low temperature and short time) together with a cationic surfactant such as cetyltrimethylammonium bromide or chloride (CTAB or CTAC), i.e., recrystallization of microporous zeolites to micro-mesoporous ones or meso-structuring of zeolites. This process prevents dissolution of the crystals by providing interactions between the surfactant and the zeolite, and almost complete recovery is achieved as a result of reorganization of the zeolite lattice around surfactant micelles [11,12,13].…”

Catalytic upgrading of bio‐oils by esterification

“…The majority of zeolites are highly microporous, which raises issues pertaining to mass transport limitations for bulky substrates imposed by their lack of porosity beyond the micropore region. There has been much interest in the development of zeolites with either hierarchical pore networks or larger more accessible pore diameters . Introduction of a hierarchical pore structure within zeolites can be achieved via one of two methods, templating and/or desilication; the former being part of the synthetic procedure for making the zeolite, the latter being a post‐synthetic modification .…”