title: NMR signal enhancement for hyperpolarized fluids continuously generated in hydrogenation reactions with parahydrogen.
abstract: In the present study we analyze the factors which can lower hyperpolarization of fluids produced in a continuous flow regime by the parahydrogen-induced polarization technique. We use the findings of this analysis to examine the flow rate dependence of propane hyperpolarization produced in the heterogeneous propylene hydrogenation by parahydrogen over Rh/TiO2 catalyst. We have estimated the maximum attainable propane (1)H hyperpolarization yield and the corrected percentage of pairwise hydrogen addition in heterogeneous hydrogenation, which was found to be ∼7%. The approach developed for polarization analysis is useful for the optimization of experimental setup and reaction conditions to obtain maximum hyperpolarization for parahydrogen-based catalyst-free continuously generated fluids applicable in biomedical magnetic resonance imaging.
authors.affiliation: International Tomography Center, Siberian Branch of the Russian Academy of Sciences, 3A Institutskaya Street, Novosibirsk, Russia , 630090.
authors.forename: Danila A
authors.initials: DA
authors.lastname: Barskiy
authors.forename: Oleg G
authors.initials: OG
authors.lastname: Salnikov
authors.forename: Kirill V
authors.initials: KV
authors.lastname: Kovtunov
authors.forename: Igor V
authors.initials: IV
authors.lastname: Koptyug