Synthesis of POM@Porphyrin COF heterogeneous catalyst for oxidative desulfurization of thio compounds

• Published in: Inorganica Chimica Acta 2023-12, Vol.558, p.121745, Article 121745
• Main Authors: Mushtaq, Afshan, Fatima, Rubab, Shehzad, Farooq Khurum, Ammar, Muhammad, Shaaban, Ibrahim A., Assiri, Mohammed A., Sajid, Muhammad, Asif, Hafiz Muhammad, Hussain, Shahid
• Format: Article
• Language: English
• Subjects: Catalysis; Dibenzothiophene; Energiteknik; Energy Engineering; Oxidative desulphurization; Polyoxometalates; Porphyrin
• ISSN: 0020-1693; 1873-3255; 1873-3255
• DOI: 10.1016/j.ica.2023.121745

[Display omitted] •Synthesized MnTP@ZnAdCOF was characterized and its use as a catalyst in ODS was studied.•Desulphurizing ability of MnTP@ZnAdCOF was above than 98% for thiobenzoic acid.•RP-HPLC chromatograms for thiobenzoic acid represented the catalytic effect of MnTP@ZnAdCOF.•Effect of different temperatures and H2O2/TB molar ratio on ODS process was observed.•Kinetic study was done in order to determine the percentage desulfurization for TB. Sulfur compounds cause substantial environmental pollution problems, and their immediate removal is urgently needed to keep the environment clean. Fuel desulfurization is necessary due to the severe impacts of sulfur on humans, wildlife, and crops when emitted into the atmosphere during fuel combustion. Fuels with high sulfur contents used in automobiles and factories are the primary source of atmospheric sulfur. A new covalent organic framework (COF) MnTP@ZnAdCOF [(N(C4H9)4]12[{NHC(CH2O)3}4(CO)4C44H24N4Mn(OCOCH3)][ZnMo6O18]4 is synthesized and characterized thoroughly using FT-IR, UV/visible, 1HNMR, TGA, PXRD, SEM-EDX, cyclic voltammetry and fluorescence spectroscopy. Herein, an environmentally safe and cost-effective approach for the ODS of thiobenzoic acid is reported using H2O2 as an oxidant and MnTP@ZnAdCOF as a heterogenous catalyst under mild reaction conditions. Desulphurization results of the catalyst are confirmed by the RP-HPLC technique using acetonitrile and water in a 50:50 M ratio as a mobile phase. Active intermediates [(Por)(OAc)Mn-OOH]−, [(Por)(OAc)MnIVO] and Mo(O2) are formed due to oxidation of Mn and Mo metal in the presence of H2O2 considered responsible for the excellent catalytic efficiency of MnTP@ZnAdCOF catalyst up to 98% desulphurization efficiency was observed. Incredible catalytic conversion of dibenzothiophene, thiobenzoic acid and the mixture of different Sulphur containing compounds to sulfoxide is observed at 25 ℃ temperature. The H2O2/S molar ratio of 5:1 is an outstanding achievement that can be utilized for the oxidation of sulfur compounds present in diesel to reduce the sulfur contents of fuel.