biostudies-literatureUnknown15(53)Cabral NMPetroleum coke (petcoke) samples containing silica sand (SiO₂) in the concentrations of ∼50 and 7 wt% were functionalized with nitric acid and hydrogen peroxide to produce carbon-based solid acid catalysts by converting the inherent sulfur species in petcoke to sulfonic acid sites (-SO₃H). The effect of SiO₂ content and functionalization agent on the physical, surface, and acidic properties of the prepared materials were evaluated, and their catalytic activities were assessed in the esterification reaction of octanoic acid and methanol at 60 °C, yielding 17-54% of ester after 6 h. The functionalization with H₂O₂ is more environmentally friendly than with HNO₃ and produces more active catalysts (ester yields of 54% and 45%, rRSC advances45453-45466https://www.ebi.ac.uk/biostudies/studies/S-EPMC12631174biostudies-literatureImproving the conversion of petroleum coke to solid acid catalysts - effectiveness of hydrogen peroxide and impact of silica contamination.PMC12631174Hill JMCabral NMfalseImproving the conversion of petroleum coke to solid acid catalysts - effectiveness of hydrogen peroxide and impact of silica contamination.Petroleum coke (petcoke) samples containing silica sand (SiO₂) in the concentrations of ∼50 and 7 wt% were functionalized with nitric acid and hydrogen peroxide to produce carbon-based solid acid catalysts by converting the inherent sulfur species in petcoke to sulfonic acid sites (-SO₃H). The effect of SiO₂ content and functionalization agent on the physical, surface, and acidic properties of the prepared materials were evaluated, and their catalytic activities were assessed in the esterification reaction of octanoic acid and methanol at 60 °C, yielding 17-54% of ester after 6 h. The functionalization with H₂O₂ is more environmentally friendly than with HNO₃ and produces more active catalysts (ester yields of 54% and 45%, r2025-01-01T00:00:00Z2025 Nov2026-06-05T17:14:29.881Z2026-05-19T03:11:47.293ZS-EPMC126311744128022010.1039/d5ra05900c