Water-selective zeolite membranes

The yield of many gas-phase industrial reactions is limited by the formation of water as a by-product. Li et al. harnessed the water-sieving properties of NaA zeolite crystals by forming them into continuous defect-free membranes within tube reactors (see the Perspective by Carreon). These membranes can let water pass but reject gases such as hydrogen, carbon monoxide, and carbon dioxide (CO 2 ). When these membranes were used in CO 2 hydrogenation to form methanol with water as a by-product, substantial increases were observed in both the CO 2 conversion and methanol yield.

Science, this issue p. 667; see also p. 624