110th Anniversary: Sustainable Synthesis of Zeolites: From Fundamental Research to Industrial Production

Zeolites, as a class of porous materials with ordered networks of micropores, have been widely used for decades in industrial applications such as catalysis, ion exchange, and adsorption and separation. In general, their syntheses are not sustainable, because hydrothermal synthesis requires the presence of costly and toxic organic templates and a large amount of a solvent such as water; the removal of organic templates by calcination generates large amounts of polluting gases such as NOx and CO2, whereas the use of water as a solvent produces a huge amount of polluted water. This report summarizes sustainable routes for synthesizing zeolites, such as the use of cheap and nontoxic organic templates, organotemplate-free synthesis, solvent-free synthesis, and a combined strategy with the organotemplate-free and solvent-free routes. Furthermore, industrial production of typical zeolites from these sustainable routes is shown, which offers a good opportunity for sustainable production and wide applications of zeolite products in the future.