Textural variations of acid‐treated serpentine

Girgis, Badie S.; Mourad, W.E.

doi:10.1002/jctb.5020260103

Cited by 5 publications

(2 citation statements)

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“…The acid–base bifunctional catalyst was prepared by acid treatment of a naturally abundant serpentine mineral, which is a group of rock-forming hydrous magnesium iron phyllosilicate ((Mg,Fe) 3 Si 2 O 5 (OH) 4 ) minerals commonly used as a source for magnesium. It has been reported that acid treatment can change the textural properties of serpentine, forming a high-surface-area material with increased accessibility to the active metal sites. − Since acid treatment can introduce acidic sites and leach out basic metals, the relative acidity versus basicity could be tuned by the extent of the acid treatment. Eight major products from carbohydrate pyrolysis, including acetaldehyde, acetone, acetol, methylglyoxal, methyl vinyl ketone, furfural, 5-methylfurfural, and 5-hydroxymethylfurfural (HMF), were chosen as representative model compounds.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Deoxygenation of Bio-Oil Model Compounds over Acid–Base Bifunctional Catalysts

et al. 2016

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An acid−base bifunctional catalyst was synthesized by treating a natural mixed-metal oxide, serpentine, with sulfuric acid. Catalyst characterization revealed that the number of acidic and basic sites increased after the acid treatment largely due to an increase in surface area. However, stronger acid sites were also introduced by the formation of bridged hydroxyl groups between a Si atom and a heteroatom, as inferred by H NMR and NH 3 -TPD analysis. Results from SEM-EDS and 1 H NMR suggested that the acid and base sites were in close proximity. Catalytic conversions of carbohydrate-derived bio-oil model compounds were performed over different acid/base catalysts. Eight single bio-oil model compounds and two binary mixtures were used. The reactivity of the model compounds was found to be strongly correlated to the number of oxygencontaining functional groups in the reactant. The results from the binary mixtures showed that the acid−base bifunctional catalyst had the highest activity in aldol condensation reactions. The best deoxygenation performance was also observed with the bifunctional catalyst for the model compounds. Reaction pathways were proposed on the basis of an isotope labeling study. Deoxygenation reactions were found to be promoted by the cooperative catalysis between closely located acid and base sites.

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Section: Introductionmentioning

confidence: 99%

Catalytic Deoxygenation of Bio-Oil Model Compounds over Acid–Base Bifunctional Catalysts

et al. 2016

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“…It was suggested that the calcination needs a significant amount of energy to change the structure of the mineral from crystalline to amorphous state. In addition, the use of high molar sulfuric acid and hydrochloric acid was reported to extract MgO from serpentine to produce porous and amorphous silica (Kosuge, 1997;Petrovski, 1987;Girgis, 1976). However, their methods needed very high acid concentration and relatively high temperature for the leaching being used to remove magnesium from serpentine.…”

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confidence: 96%