Organotemplate-Free Routes for Synthesizing Zeolites

Some zeolites such as ZSM-5 and β that applied widely in industrial processes normally require the presence of organotemplates in their synthesis, which usually results in the pollution of environments and the emission of carbon dioxide and nitrogen oxides. Organotemplate-free routes for synthesizing zeolites are good ways to solve these problems because of the low cost, energy saving, emission reduction, and consequent huge economic benefits. This review describes the novel routes for synthesizing zeolites in the absence of organotemplates published recently, including the synthesis of ECR-1 zeolite by adjusting the starting composition in the gel, the synthesis of ZSM-34 zeolite using zeolite L seeds solution, and the synthesis of β zeolite using β crystals as seeds in the starting gel.