New insights on the selective sequestration of gas molecules appearing in Nature Communications

Assistant Professor Jin Shang's work on the design of highly porous materials for the sequestration of gas molecules appears in Nature Communications. By collaborating with Researchers from Australia and USA, Dr Shang and the team clarified for the first time, the mechanism of selective admission of guest molecules into the cage of the porous materials. This is a paradigm shift to what people thought they had understood for a long time, i.e., on the idea of molecular sieving, where gas molecules smaller than the pore openings are admitted. Not entirely true it seems!

Explaining that the achievement is built on Dr Shang’s previous discovery of “molecular trapdoor” mechanism, the introduction of cation bouncers on the door of the pores can keep out undesirable gases like methane while letting in carbon dioxide despite the latter being larger in size. Based on this concept, it is now possible to tune microporous materials to exclusively sequester targeted gas molecules, for example, carbon dioxide from other molecules in the exhaust of coal-fired power plants. As quipped by Dr Shang, "People have long been dreaming of actively controlling such selective guest admission behaviour because of their huge potential applications."

Although the team demonstrated the selective sequestration, storage and release of gases using simple temperature control, the materials can potentially be controlled using other means such as light and electric field. These are promising to the key industrial gas separation applications including the carbon capture and natural gas purification, removal of NOx from roadside emissions, as well as smart gas storage (e.g., hydrogen and methane) without needing sustained gas pressure. As a Principal Investigator of the Joint Laboratory for Energy and Environmental Catalysis, Dr Shang is also exploring their potentials in critical catalytic applications.