Isotope-Edited Fourier Transform Infrared Spectroscopy in Elucidating Surface Organic Species for Applications in Energy and Materials Science

Abstract

Organic reagents are commonly employed in making a wide range of materials and play crucial roles in enabling their activities or performances. However, the identity of organics in the final stages of active species is challenging to characterize, and the mechanisms of organics in active material development are difficult to understand due to limited techniques available at the heterogeneous interface of organic and inorganic phases. Hence, we present a study using isotopeedited FT-IR to elucidate the specific groups contributing to an IR marker band and shed light on the transformation mechanisms. The molecular source of the marker band at 1710 cm −1 was identified as a crucial problem for improving the activity of a propietary material under commercial development. This IR marker band was presumably a result of the orgnic molecules oleic aicds or oleylamine during synthesis. However, the prevailing hypotheses on the existing carbonyls from oleic acids or from the oxidation of most likely α-carbons of the oleylamine as the cause of the IR marker were ruled out using 1-13 C-isotope-labeled compounds. Suprisingly, the marker band was found to be associated with the remaining 17 carbons in oleic acids or oleylamine (most likely the olefinic double bonds), confirmed by the IR shift due to specific isotope labels at these positions. We demonstrate that isotope-edited FT-IR is a powerful technique in characterizing surface organic species on active materials, catalysts, or porous media materials with broad applications in energy and materials sciences.

Sprayable Superhydrophobic Polydopamine-Modified Oleic Acid/Nanoscale SiO2Composites for Insulator Protective Coatings

“…The peaks at 2526 and 2855 cm –1 show a long alkyl chain attached with oleic acid-modified nano-SiO 2 particles that greatly enhance the hydrophobic properties of the insulator surface . 1410 and 1556 cm –1 correspond to COO ‑ the vibrate peak . As a result, it is proven that oleic acid −COOH has interacted with OH on the surface of SiO 2 to produce carboxylate.…”

“…23 1410 and 1556 cm −1 correspond to COOthe vibrate peak. 24 As a result, it is proven that oleic acid −COOH has interacted with OH on the surface of SiO 2 to produce carboxylate. The OH peak at 3430 cm −1 represents unreacted OH on the surface of SiO 2 nanoparticles.…”

2022 Pioneers in Energy Research: Oliver Mullins

“…58 Dr. Zhang from ExxonMobil reported a study using a new isotope-edited Fourier transform infrared (FTIR) technique to elucidate surface organic species, with potential applications in energy and material sciences. 59 Prof. Ehlig-Economides from the University of Houston provided an account of the hydrogen economy from analyses of energy efficiencies of various hydrogen generation technologies to…”

“…Prof. Hartman from New York University provided a more focused minireview on the application of microfluidics to study asphaltenes in upstream production . Dr. Zhang from ExxonMobil reported a study using a new isotope-edited Fourier transform infrared (FTIR) technique to elucidate surface organic species, with potential applications in energy and material sciences . Prof. Ehlig-Economides from the University of Houston provided an account of the hydrogen economy from analyses of energy efficiencies of various hydrogen generation technologies to address the challenges during energy transition and reduce carbon emissions …”

Determination of Stretching Frequencies by Isotopic Substitution Using Infrared Spectroscopy: An Upper-Level Undergraduate Experiment for an In-Person or Online Laboratory

“…Isotopic labeling studies are commonly used by researchers to elucidate reaction mechanisms, − probe biological structure, − and facilitate spectroscopic analyses. − Although this is an important research tool, students often have limited lab experiences utilizing isotopes in experiments beyond deuterated NMR solvents, and to a lesser extent experiments that use isotopic labeling to probe kinetic isotope effects and mechanisms. − Additional experiments that combine instrumental methods and isotopic labeling have been reported ,, including ones that utilize vibrational spectroscopy such as the classic physical chemistry lab investigating the vibrational–rotational spectra of HCl and DCl. , Significantly, Ben-Amotz and co-workers published an experiment comparing experimental and theoretical results from Raman and IR measurements that includes vibrational studies of methanol and methanol-d 1 . This experiment provides a rigorous demonstration of the use of isotopic labeling in peak assignment of the O–H stretch.…”