Selective Single-Site Pd-In Hydrogenation Catalyst for Production of Enhanced Magnetic Resonance Signals using Parahydrogen

Dudari B Burueva; Kirill V Kovtunov; Andrey V Bukhtiyarov; Danila A Barskiy; Igor P Prosvirin; Igor S Mashkovsky; Galina N Baeva; Valerii I Bukhtiyarov; Aleksandr Yu Stakheev; Igor V Koptyug

doi:10.1002/chem.201705644

Selective Single-Site Pd-In Hydrogenation Catalyst for Production of Enhanced Magnetic Resonance Signals using Parahydrogen

Chemistry. 2018 Feb 21;24(11):2547-2553. doi: 10.1002/chem.201705644. Epub 2018 Jan 29.

Authors

Dudari B Burueva^{1

2}, Kirill V Kovtunov^{1

2}, Andrey V Bukhtiyarov³, Danila A Barskiy⁴, Igor P Prosvirin^{2

3}, Igor S Mashkovsky⁵, Galina N Baeva⁵, Valerii I Bukhtiyarov³, Aleksandr Yu Stakheev⁵, Igor V Koptyug^{1

2}

Affiliations

¹ Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, 3A Institutskaya St., 630090, Novosibirsk, Russia.
² Novosibirsk State University, 2 Pirogova St., 630090, Novosibirsk, Russia.
³ Boreskov Institute of Catalysis, SB RAS, 5 Acad. Lavrentiev Pr., 630090, Novosibirsk, Russia.
⁴ Department of Chemistry, University of California at Berkeley, Berkeley, CA, 94720-3220, USA.
⁵ N.D. Zelinsky Institute of Organic Chemistry, RAS, 47 Leninsky Pr., 119991, Moscow, Russia.

PMID: 29322571
DOI: 10.1002/chem.201705644

Abstract

Pd-In/Al₂ O₃ single-site catalyst was able to show high selectivity (up to 98 %) in the gas phase semihydrogenation of propyne. Formation of intermetallic Pd-In compound was studied by XPS during reduction of the catalyst. FTIR-CO spectroscopy confirmed single-site nature of the intermetallic Pd-In phase reduced at high temperature. Utilization of Pd-In/Al₂ O₃ in semihydrogenation of propyne with parahydrogen allowed to produce ≈3400-fold NMR signal enhancement for reaction product propene (polarization=9.3 %), demonstrating the large contribution of pairwise hydrogen addition route. Significant signal enhancement as well as the high catalytic activity of the Pd-In catalyst allowed to acquire ¹ H MR images of flowing hyperpolarized propene gas selectively for protons in CH, CH₂ and CH₃ groups. This observation is unique and can be easily transferred to the development of a useful MRI technique for an in situ investigation of selective semihydrogenation in catalytic reactors.

Keywords: MRI; bimetallic catalysts; heterogeneous hydrogenation; parahydrogen; parahydrogen-induced polarization.