CAREER: Catalytic Membranes for Integrated CO2 Capture and Conversion

Carbon dioxide (CO2) capture from air is considered an important negative emissions technology to mitigate global warming. Current sorbent-based CO2 capture processes are prohibitively expensive because the sorbent must be regenerated via an energy-intensive step to release the captured CO2. Once released from the sorbent, the captured CO2 must also be compressed and transported to sites for storage, which further reduces efficiency. An ideal CO2 capture technology would be both high-capacity and energy-efficient, while simultaneously converting the waste CO2 stream into a value-added product. This project will advance the fundamental science of integrating CO2 capture with CO2 conversion in a single unit process using a newly-envisioned bifunctional catalytic membrane. The membrane would act as both the CO2 separation and conversion medium, providing an energy- and atom-efficient alternative to sorbent-based CO2 capture, compression, transport, and storage. Such a membrane could revolutionize the way fuels and chemicals are produced, leading to transformative change in the chemical process industries and long-term stimulation of the United States economy. The students supported by this project will receive interdisciplinary training in catalysis, membrane separations, and advanced spectroscopic characterization. This CAREER project will also broaden participation in STEM through outreach activities at Navarre Middle School in South Bend, Indiana, and research opportunities for undergraduate and graduate students from Puerto Rico. This CAREER project aims to advance the fundamental science underlying the integration of CO2 capture and conversion into a single unit, membrane-based process. The envisioned bifunctional CO2 capture and conversion membrane is polymer-based with: (1) amine groups attached to the polymer chain to selectively capture CO2 from air, or concentrated point sources, and facilitate CO2 transport across the membrane; and (2) catalytic groups (e.g. amines, halides, metals) to catalyze conversion of CO2 on the permeate side of the membrane. The research goal of this project is to identify the key factors (mass transport, reaction kinetics, and stability) that limit the overall rate of integrated CO2 capture and conversion. The project will examine cyclic carbonate synthesis as a model CO2 conversion reaction. Knowledge of the rate-limiting factors will be used to develop strategies for circumventing these performance-limiting processes. The project is innovative in its use of unique operando spectroscopy techniques developed by the investigator to probe the structure, performance, and dynamics of the catalytic membranes under realistic operating conditions. The research outcomes will provide foundational knowledge of the kinetics, mechanisms, and stability of the catalytic membrane, which will provide a framework for developing a practical membrane system for integrating CO2 capture with CO2 conversion to a wide range of fuels and chemicals. The research will also advance the state-of-the-art of operando membrane characterization, enhance membranes for CO2 separation, and enhance catalysts for CO2 conversion. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. NSF Award ID: 2619523 | Program: 01002223DB NSF RESEARCH & RELATED ACTIVIT,01002526DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Casey O'Brien | Institution: Texas Tech University, LUBBOCK, TX | Award Amount: $316,536 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2619523 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2619523.html