A layered double hydroxide nanoflake template layer triggers conversion into a highly compact MIL-53 membrane [IMAGE: BAN YUJIE AND WANG YUECHEN]

Formic acid and acetic acid are pivotal platform chemicals. Distillation-based water/acid separation requires large energy expenditure.

Separation using membranes is identified as a low-carbon technology. Metal-organic frameworks (MOFs) bring tremendous opportunities for membrane separation. Highly compact membranes benefit both separation accuracy and long-term stability. However, the preparation of such membranes for upgrading of corrosive acids is still challenging.

Recently, a research group led by Professor Yang Weishen and Dr. Ban Yujie from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) proposed a “template-guiding growth” method to prepare a highly compact MIL-53 (a class of MOF) membrane.

“This membrane can achieve complete dewatering from formic acid and acetic acid solutions, and save up to 77 percent of the energy consumption compared with traditional distillation,” said Dr. Ban.

This study was published in Angewandte Chemie International Edition on February 22.

The researchers reported that a continuous layer of ZnAl-CO₃ layered double hydroxide nanoflakes on an alumina supported as a template triggered chemical self-conversion to MIL-53 membrane.

In this process, the template guided MIL-53 crystals to replicate its imprint out-of-plane (stage 1) and modulated the availability of alumina from the alumina support for in-plane growth of MIL-53 (stage 2). The membrane could realize nearly complete dewatering from formic acid and acetic acid solutions and maintain stability in a continuous pervaporation.

For more information, please contact:

Professor & Dr. Yang Weishen

E-mail: yangws@dicp.ac.cn

Dalian Institute of Chemical Physics (DICP),

Chinese Academy of Sciences

Source: Dalian Institute of Chemical Physics (DICP),

Chinese Academy of Sciences