Perspective and outlook into green and effective approaches for zeolitic membrane preparation

Due to their well-defined porosity, physical–chemical endurance, and catalytic property, zeolite and zeotype membranes are becoming a more established choice for a broad spectrum of separation ranging from pervaporation, solvent purification, isomer separation, gas mixture separation, as well as hybrid reaction-separation process. However, the high production costs impedes the commercialization of zeolitic membrane. The hydrothermal method commonly used to synthesize zeolites is relatively energy intensive. Besides, conventional zeolitic membrane preparation produces a massive amount of wasted expensive materials and toxic organic structure directing agents. Recently, there has been an influx of research aiming to modify the conventional preparation process into cost-effective and environmentally friendly procedures. This review will discuss the challenges and prospects of the current state-of-the-art green and efficient techniques for zeolitic membrane preparation such as low temperature synthesis, low-cost materials, solvent-free and organic structure directing agents-free synthesis, and recycling mother liquor.