Fine-Tuning Simulation of the ESR Spectrum - Sensitive Tool to Identify the Local Environment of Asphaltenes In Situ
Full article
| Common |
Language:
Английский,
Genre:
Full article,
Status:
Published,
Source type:
Original
|
| Journal |
The Journal of Physical Chemistry C
ISSN: 1932-7447
, E-ISSN: 1932-7455
|
| Output data |
Year: 2022,
Volume: 126,
Number: 26,
Pages: 10729-10741
Pages count
: 13
DOI:
10.1021/acs.jpcc.2c01978
|
| Tags |
Asphaltenes; Electron spin resonance spectroscopy; Electrospinning; Heavy oil production; Magnetic moments; Molecules; Molybdenum compounds; Tensors; Tuning; Vanadium compounds |
| Authors |
Trukhan Sergey N.
1
,
Yakushkin Stanislav S.
1
,
Martyanov Oleg N.
1
|
| Affiliations |
| 1 |
Boreskov Institute of Catalysis, Lavrentiev Ave. 5, Novosibirsk 630090, Russia
|
|
Funding (1)
|
1
|
Russian Science Foundation
|
21-13-00065
|
An original method to study the local environment of vanadyl-containing components of heavy oils based on fine-tuning simulation of their electron spin resonance (ESR) spectra in situ is developed. The approach is backgrounded on precise computation of anisotropic ESR spectra of individual porphyrin complexes in specific solvents modeling a particular local environment of certain polarity using specific g and A tensor components, their dispersion, and linewidth determined by unresolved super-hyperfine interaction with the closest nitrogen. The high level of simulation accuracy allowed us to differentiate the values of the g and A tensor components related to individual vanadyl complexes in different solvents with certain polarity in reference systems and attribute the observed variation to the interaction of the vanadyl complex with surrounding molecules located in its axial direction. The method developed for the model systems is successfully applied to the real oil-based systems where different vanadyl complexes with different local environments are presented, forming the experimentally observed ESR spectrum. The Monte Carlo procedure was suggested to define the relative contribution (weight) of the individual spectra having tiny peculiarities related to vanadyl fragments in different local environments and finally mapping the g and A tensor components distribution which is characteristic for the particular oil-based sample. Extraordinary sensitivity to the localization and interaction with surrounding molecules of vanadyl-containing complexes which are present in heavy oil as a natural spin probe or can be specially introduced give us a unique opportunity to in situ study the local environment of asphaltenes and their intermolecular interactions with other oil components.