With the support from the National Natural Science Foundation of China (grants No. 22072065, 21136005, U1662107, 21938011, and 21725603), a breakthrough in the field of carbon capture by heteroatom zeolites was achieved by the collaboration of the group led by Yan Ning’s group from National University of Singapore, Xing Huabin’s group from Zhejiang University and Wang Jun's group from Nanjing Tech University. The research article entitled “Self-assembled iron-containing mordenite monolith for carbon dioxide sieving” was published in Science on July 16, 2021. The link to the paper is: https://science.sciencemag.org/content/373/6552/315

The growing CO₂ emission resulted in serious environmental and climate crisis. Carbon capture, utilization, and storage is an effective way to reduce CO₂ emission and achieve separation and recovery as well as comprehensive utilization, and is of great significance to achieve the goal of peaking carbon dioxide emissions and carbon neutrality. It remains one huge challenge to develop low-cost and efficient carbon capture technology.

To address this issue, Yan's, Xing's and Wang's groups synthesized a heteroatom mordenite monolith by developing a new hydrothermal route. The resulting material can be directly used as a self-assembled adsorbent, showing the record-high volumetric carbon dioxide uptakes and separation efficiency. The adsorbent exhibited excellent size-exclusive molecular sieving of carbon dioxide over nitrogen, methane and argon, which realized the efficient adsorption and separation of carbon dioxide in post-combustion, biogas, and natural gas purification systems. This study is considered a breakthrough in the field of carbon dioxide capture, and it opens the new applications of heteroatomic zeolites in the field of gas adsorption and separation.

Fig. 1. Self-assembled Fe-MOR monolith. A side view and top view of precisely narrowed microchannels (kinetic diameter: 3.3 to 3.4 Å) by occupying isolated tetrahedral Fe species inside the 12-MR MOR microchannel. Blue indicates Si or Al, red is O, light brown is Fe, and gray is C.

Fig. 2. Gas sorption behavior. (A) Comparison of volumetric CO₂ uptakes at 298 K. (B) Comparison of CO₂/N₂ and CO₂/CH₄ IAST selectivities at 1 bar and 298 K for the binary mixture of CO₂/N₂:15/85 and CO₂/CH₄:50/50, respectively.

(Zhi-Jian Zhao, Jie Fu, Guojun Zhang)