Iridium-Catalyzed Dehydrogenation in a Continuous Flow Reactor for Practical On-Board Hydrogen Generation From Liquid Organic Hydrogen Carriers

Alexey V Polukeev; Reine Wallenberg; Jens Uhlig; Christian P Hulteberg; Ola F Wendt

doi:10.1002/cssc.202200085

Iridium-Catalyzed Dehydrogenation in a Continuous Flow Reactor for Practical On-Board Hydrogen Generation From Liquid Organic Hydrogen Carriers

ChemSusChem. 2022 Apr 22;15(8):e202200085. doi: 10.1002/cssc.202200085. Epub 2022 Mar 25.

Authors

Alexey V Polukeev¹, Reine Wallenberg^{1

2}, Jens Uhlig³, Christian P Hulteberg⁴, Ola F Wendt¹

Affiliations

¹ Centre for Analysis and Synthesis, Department of Chemistry, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden.
² National Center for HREM, Department of Chemistry, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden.
³ Division of Chemical Physics, Department of Chemistry, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden.
⁴ Department of Chemical Engineering, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden.

Abstract

To enable the large-scale use of hydrogen fuel cells for mobility applications, convenient methods for on-board hydrogen storage and release are required. A promising approach is liquid organic hydrogen carriers (LOHCs), since these are safe, available on a large scale, and compatible with existing refueling infrastructure. Usually, LOHC dehydrogenation is carried out in batch-type reactors by transition metals and their complexes and suffers from slow H₂ release kinetics and/or inability to reach high energy density by weight, owing to low conversion or the need to dilute the reaction mixture. In this study, a continuous flow reactor is used in combination with a heterogenized iridium pincer complex, which enables a tremendous increase in LOHC dehydrogenation rates. Thus, dehydrogenation of isopropanol is performed in a regime that, in terms of gravimetric energy density, hydrogen generation rate, and precious metal content, is potentially compatible with applications in a fuel-cell powered car.

Keywords: dehydrogenation; flow chemistry; iridium; liquid organic hydrogen carriers; pincer complexes.

Abstract

Grants and funding