Milling Activation for the Solvent-Free Synthesis of Zeolites. A Practical Guide

Abstract

The paramount challenge of current chemical technology, including catalysis, is meeting the ecological sustainability requirements. The feasible production of zeolites is crucial because they constitute the principal group of heterogeneous catalysts. However, current zeolite manufacturing via hydrothermal synthesis is connected with considerable consumption of water resources, generation of wastewater, and significant equipment costs. Solvent-free strategies have attracted great attention as high-yielding methods for sustainable synthesis, particularly beneficial in terms of water consumption minimization and an outstanding increase in production due to the efficient use of synthesis space capacity. So far, the solvent-free preparation of numerous zeolite materials has been performed with the preceding grinding of reagents in a mortar. The proposed article describes recent advances in the application of automatized milling instead of manual work. Pretreatment automatization makes the entire process well-controlled, less sensitive to human factors, and is significantly more relevant to industrial scale-up. Moreover, the automatized milling activation unlocks opportunities for solvent-free synthesis from a broader range of common reagents, where the manual treatment is not efficient. Possibilities and limitations of the milling methods are discussed on the basis of a comprehensive analysis of parameter optimization, activation mechanisms, and applicability of common reagents used for zeolite production.