A scalable zinc-based coordination network for energy-efficient NF₃/CF₄ separation with unprecedented selectivity.

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Nitrogen trifluoride (NF3) and carbon tetrafluoride (CF4) are essential in semiconductor manufacturing.
• Current separation methods for NF3 and CF4 are ineffective, leading to costly waste and environmental issues.
• The similar physicochemical properties of NF3 and CF4 present a significant separation challenge.

Purpose of the Study:

• To develop an efficient method for separating nitrogen trifluoride (NF3) from carbon tetrafluoride (CF4).
• To address the environmental and economic challenges associated with waste emissions in semiconductor manufacturing.
• To demonstrate the efficacy of a specific metal-organic framework for gas separation.

Main Methods:

• Utilized a zinc-based metal-organic framework (CALF-20) with precisely tuned 4.8 Å pores.
• Employed molecular sieving as the primary separation mechanism.
• Conducted breakthrough experiments and structural/computational studies for characterization.

Main Results:

• CALF-20 achieved exceptional NF3/CF4 separation via molecular sieving.
• A record NF3/CF4 adsorption ratio of 41.1 was observed at 298 K.
• CF4 purity of 99.5% was attained, with preferential adsorption of NF3 due to pore size selectivity.

Conclusions:

• CALF-20 demonstrates superior performance in NF3/CF4 separation, enabling efficient gas purification.
• The developed material offers a cost-effective solution ($12.3/kg) for sustainable semiconductor manufacturing.
• This research provides a practical approach to mitigate waste emissions and environmental impact.