Magnetic Resonance Imaging in Situ Visualization of an Electrochemical Reaction under Forced Hydrodynamic Conditions

Abstract

Magnetic resonance imaging (MRI) has proven to be a powerful tool for the characterization and investigation of in situ chemical reactions. This is more relevant when dealing with complex systems, where the spatial distribution of the species, partition equilibrium, flow patterns, among other factors have a determining effect over mass transport and therefore over the reaction rate. The advantage of MRI is that it provides spatial information in a noninvasive way and does not require any molecular sensor or sample extraction. In this work, MRI is used to fully characterize an electrochemical reaction under forced hydrodynamic conditions. Reaction rates, flow patterns, and quantitative concentration of the chemical species involved are spatially monitored in situ in a complex system that involves metallic pieces and a heterogeneous cementation reaction. Experimental data are compared with numerical simulations.

Mapping of Lithium-Ion Battery Electrolyte Transport Properties and Limiting Currents with In Situ MRI

“…[10][11][12] Given the complexity and interdependency of the ion transport and intercalation processes in electrochemical systems, it is therefore unsurprising that in situ and operando methods for their study have proliferated and become widely accepted. 13,14 Magnetic resonance imaging (MRI) has been at the forefront of this development, with applications to fuel cells, 15,16 metal-air battery electrolytes, 17 electrodeposition, [18][19][20] and supercapacitors. 21,22 In lithium-ion cells, MRI has been used to study lithium insertion 23,24 and plating, [25][26][27][28] lithium distribution heterogeneity in solid-state electrolytes, 29 and transport processes in liquid electrolytes.…”

Opportunities for Characterizing Geological Flows Using Magnetic Resonance Imaging

“…Prior studies have used MRI to image spatial heterogeneities in reaction and changes in reaction extent over time in liquid reactions flowing through porous media based on chemical shift contrast ( Gladden et al., 2010 ). Other studies have investigated propagating chemical species wave fronts in liquid-phase autocatalytic reactions subject to different flow conditions based on changes in relaxation times of different species and pulse sequences designed to distinguish between relaxation times of the different chemical species ( Britton, 2006 ; Koptyug et al., 2003 ; Serial et al., 2018 ). Gas-phase reactions catalyzed by solid catalysts have also been imaged utilizing parahydrogen induced polarization, a phenomenon in which hyperpolarized hydrogen reacts with an alkene to produce an alkane, and the alkane product has high MRI signal, yet the reactants have insignificant MRI signal ( Bouchard et al., 2008 ).…”