Self-Optimization of Continuous Flow Electrochemical Synthesis Using Fourier Transform Infrared Spectroscopy and Gas Chromatography

Ke, Jie; Gao, Chuang; Folgueiras-Amador, Ana A.; Jolley, Katherine E.; de Frutos, Oscar; Mateos, Carlos; Rincón, Juan A.; Brown, Richard C.D.; Poliakoff, Martyn; George, Michael W.

Abstract

A continuous-flow electrochemical synthesis platform has been developed to enable self-optimization of reaction conditions of organic electrochemical reactions using attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) and gas chromatography (GC) as online real-time monitoring techniques. We have overcome the challenges in using ATR FT-IR as the downstream analytical methods imposed when a large amount of hydrogen gas is produced from the counter electrode by designing two types of gas–liquid separators (GLS) for analysis of the product mixture flowing from the electrochemical reactor. In particular, we report an integrated GLS with an ATR FT-IR probe at the reactor outlet to give a facile and low-cost solution to determining the concentrations of products in gas–liquid two-phase flow. This approach provides a reliable method for quantifying low-volatile analytes, which can be problematic to be monitored by GC. Two electrochemical reactions the methoxylation of 1-formylpyrrolidine and the oxidation of 3-bromobenzyl alcohol were investigated to demonstrate that the optimal conditions can be located within the pre-defined multi-dimensional reaction parameter spaces without intervention of the operator by using the stable noisy optimization by branch and FIT (SNOBFIT) algorithm.

Citation

Ke, J., Gao, C., Folgueiras-Amador, A. A., Jolley, K. E., de Frutos, O., Mateos, C., …George, M. W. (2022). Self-Optimization of Continuous Flow Electrochemical Synthesis Using Fourier Transform Infrared Spectroscopy and Gas Chromatography. Applied Spectroscopy, 76(1), 38-50. https://doi.org/10.1177/00037028211059848

• Journal Article Type: Article
• Acceptance Date: Aug 23, 2021
• Online Publication Date: Dec 15, 2021
• Publication Date: Jan 1, 2022
• Deposit Date: Jan 26, 2022
• Publicly Available Date: Feb 2, 2022
• Journal: Applied Spectroscopy
• Print ISSN: 0003-7028
• Electronic ISSN: 1943-3530
• Publisher: SAGE Publications
• Peer Reviewed: Peer Reviewed
• Volume: 76
• Issue: 1
• Pages: 38-50
• DOI: https://doi.org/10.1177/00037028211059848
• Keywords: Flow chemistry; self-optimization; electrosynthesis; Fourier transform infrared Spectroscopy; FT-IR; gas separation
• Public URL: https://nottingham-repository.worktribe.com/output/7340454
• Publisher URL: https://journals.sagepub.com/doi/10.1177/00037028211059848
• Additional Information: Ke J, Gao C, Folgueiras-Amador AA, et al. Self-Optimization of Continuous Flow Electrochemical Synthesis Using Fourier Transform Infrared Spectroscopy and Gas Chromatography. Applied Spectroscopy. 2022;76(1):38-50. doi:10.1177/00037028211059848