Electrocatalytic Oxidation of Dibenzothiophene and 4,6-Dimethyldibenzothiophene at Gold-Polyaniline (Au-PANI) Composite
- PDF / 3,345,363 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 86 Downloads / 156 Views
ORIGINAL RESEARCH
Electrocatalytic Oxidation of Dibenzothiophene and 4,6-Dimethyldibenzothiophene at Gold-Polyaniline (Au-PANI) Composite Electrodes Siyabonga Shoba 1 & Owolabi M. Bankole 1 & Adeniyi S. Ogunlaja 1
# Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract In this study, glassy carbon electrodes modified with gold-polyaniline (Au-PANI) were evaluated for the ability to electrochemically oxidize dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). Au-PANI was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), transmission electron micrograph (TEM), and scanning electron micrograph (SEM). The role of nitrogen groups of PANI on the formation of Au-PANI was shown by FT-IR. XPS confirmed the various electronic states and environment of oxygen, nitrogen, gold, and carbon in Au-PANI film. TEM results indicated that Au particle size is in the range of 3.50–6.97 nm, while SEM results confirmed the heterogeneous nature of PANI and Au-PANI surfaces. In this study, density functional theory (DFT) with the B3LYP functional and 6-311++ G** basis set was used to examine the electronic properties of DBT/4,6-DMDBT onto the surface of PANI nanocomposite. Electrochemical tests indicate that the Au-PANI exhibits high catalytic activity for DBT and 4,6-DMDBT electrooxidation. Oxidation products such as DBTO = dibenzothiophene sulfoxide; 4,6-DMDBTO = 4,6-dimethydibenzothiophene sulfoxide; DBTO2 = dibenzothiophene sulfone; and 4,6-DMDBTO2 = 4,6-dimethydibenzothiophene sulfone were confirmed by means of gas chromatograph coupled to mass spectrometer (GC-MS), 1H, and 13C NMR. Keywords Electrooxidation . Polyaniline (PANI) . Electrosynthesis . Dibenzothiophene . 4,6-Dimethyldibenzothiophene
Introduction Fuel oils contain mixture of compounds in varying quantities among which are sulfur, oxygen, and nitrogen-containing compounds [1–3]. The negative impact of organosulfur compounds (OSCs) such as dibenzothiophenes (DBTs) and its analogues in fuels is well known. The combustion of OSCs result in SOX emissions, which is associated with the formation of acid rains, poisoning of refining catalysts, and catalytic converters of combustion engines. Their presence is also responsible for the pollution of the environment, hence,
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12678-020-00617-8) contains supplementary material, which is available to authorized users. * Adeniyi S. Ogunlaja [email protected] 1
Department of Chemistry, Nelson Mandela University, PO Box 77000, Port Elizabeth 6031, South Africa
affecting the public health [3–5]. Efforts are made to reduce sulfur content in fuels. Hydrodesulfurization (HDS) technology is currently applied for the removal of OSCs [5]. In this process, hydrogen gas, high pressures, and temperatures (300–350 °C) are required for the removal of sulfur in fuels. Nonetheless, HDS suffers some demerits such as high-energy consumption process, us
Data Loading...
