Mesoporous sulfonic acid silicas for pyrolysis bio-oil upgrading via acetic acid esterification

Abstract

Propylsulfonic acid derivatised SBA-15 catalysts have been prepared by post modification of SBA-15 with mercaptopropyltrimethoxysilane (MPTS) for the upgrading of a model pyrolysis bio-oil via acetic acid esterification with benzyl alcohol in toluene. Acetic acid conversion and the rate of benzyl acetate production was proportional to the PrSO 3 H surface coverage, reaching a maximum for a saturation adlayer. Turnover frequencies for esterification increase with sulfonic acid surface density, suggesting a cooperative effect of adjacent PrSO 3 H groups. Maximal acetic acid conversion was attained under acid-rich conditions with aromatic alcohols, outperforming Amberlyst or USY zeolites, with additional excellent water tolerance.

A new application for transition metal chalcogenides: WS2 catalysed esterification of carboxylic acids

“…WS 2 is hence an exceptional solid acid catalyst for palmitic acid esterification, an important step in the commercial production of biodiesel production from plant oils. Water is an inevitable by-product of esterification, but a common problem for many solid acid catalysts [15,27,34], as observed for e.g. acrylic acid esterification with butanol over Figure 3).…”

“…However, there are no reports on their application as solid acid catalysts for sustainable chemical transformations, such as the upgrading of pyrolysis bio-oils through carboxylic acid neutralisation [15] or biodiesel production from free fatty acid components of non-edible plant and algal oils [16][17][18][19] [14,20]. The solid acidity of WS 2 was probed through NH 3 and propylamine chemisorption and temperature-programmed desorption, in order to quantify their acid loadings and relative strengths.…”

Cu and Fe oxides dispersed on SBA-15: A Fenton type bimetallic catalyst for N,N -diethyl- p -phenyl diamine degradation

“…11a,b) revealed significant changes in the organic species present, with the intensities of C H and C C bands [51,52] between 2800 and 3000 cm −1 and 1000-1500 cm −1 (indicative of alkyl, amine and phenyl groups) decreasing post-reaction. Atomic absorption spectroscopy of the filtrate and spent catalyst recovered after DPD degradation revealed negligible Cu and Fe leaching (<0.5 ppm and 0.2 ppm leached respectively), equating to ∼2-5% of the original transition metal incorporated into the catalyst.…”

Water Tolerant and Reusable Sulfonated Hyperbranched Poly(aryleneoxindole) Acid Catalyst for Solvent‐Free Esterification

“…The group of Wilson thoroughly investigated the water tolerance of propylsulfonic acid functionalized mesoporous silica (PrSO 3 H/SBA‐15). In a first report, the acid catalyzed esterification of benzyl alcohol was deliberately spiked with 40 mol% of water with respect to benzyl alcohol . No impact on the initial reaction rate was observed, however overall conversion decreased from 100 to 60% after 5 h of reaction which was attributed to a displacement of the reaction equilibrium to the reverse hydrolysis reaction.…”

“…In a first report, the acid catalyzed esterification of benzyl alcohol was deliberately spiked with 40 mol% of water with respect to benzyl alcohol. [24] No impact on the initial reaction rate was observed, however overall conversion decreased from 100 to 60% after 5 h of reaction which was attributed to a displacement of the reaction equilibrium to the reverse hydrolysis reaction. It is also important to note that a ratio of 2:1 (acid:alcohol), toluene and a temperature of 100 8C were used shifting the reaction equilibrium to the desired ester.…”