Chemicals from Renewables: Aerobic Oxidation of Furfural and Hydroxymethylfurfural over Gold Catalysts

Advances in Base-Free Oxidation of Bio-Based Compounds on Supported Gold Catalysts

“…Au-based catalysts have been successfully applied for the oxidative esterification of alcohols [71][72][73][74] and were also explored for the transformation of HMF. The first example of esterification of HMF to produce dimethyl-2-furoate required the use of a base [75]. Subsequently, Corma et al reported an Au/CeO2 catalyst able to perform the reaction under base-free conditions [56].…”

“…Subsequently, Corma et al reported an Au/CeO2 catalyst able to perform the reaction under base-free conditions [56]. This catalyst displayed full conversion of HMF in a 2 h reaction, but The first example of esterification of HMF to produce dimethyl-2-furoate required the use of a base [75]. Subsequently, Corma et al reported an Au/CeO 2 catalyst able to perform the reaction under base-free conditions [56].…”

“…Methyl-2-furoate is used as a flavor and fragrance as well as in other processes in fine chemical industry [81,82]. The first example of esterification of furfural to produce methyl-2-furoate required the use of a base [75]. However, the high performance of the Au/CeO 2 catalyst under base-free conditions, reported by Casanova et al, inspired the development of Au-based catalysts for the base-free oxidative esterification of furfural [56].…”

The effects of gold nanosize for the exploitation of furfural by selective oxidation

“…However, additional transformations of furfural are highly desired: among these, the synthesis of alkyl furoates can open very interesting perspectives for the use of xyloses. Recently it has been shown that furfural can be quite easily converted in methyl furoate by an oxidative esterification with a NaCH 3 O solution in CH 3 OH with O 2 at 22 °C on a Au/TiO 2 reference catalyst purchased by the World Gold Council [1], while in the absence of the base experimental conditions must be strongly raised up [2]. Gold nanoparticles have been recognized as a very good catalyst for selective oxidation with molecular O 2 but it's known that there is a limiting size dividing active from inactive catalysts.…”

Advances in selective catalytic transformation of ployols to value-added chemicals

“…Taarning et al [129] reported the oxidation of HMF catalyzed by Au/TiO2 using methanol as solvent. A stoichiometric ester of FDCA was formed in the presence of catalytic amounts of sodium methoxide (8 mol%).…”