Switching Selectivity in the Hydrogen Transfer Reduction of Furfural

Abstract

Supported Cu catalysts and bare inorganic oxides have been tested in the reduction of furfural to furfuryl alcohol under hydrogen transfer reaction conditions by using butanol as a donor. Bare oxides like zirconia and alumina were found to be more active than the corresponding supported catalysts and in particular high surface Zirconia gave a quantitative transformation of the aldehyde into alcohol in 2,5 h at 140 °C according to a pure Meerwein‐Ponndorf‐Verley mechanism. Competitive dehydrogenation of the alcohol formed on the surface of Cu catalysts strongly reduces their activity although selectivity to alcohols on zirconia and alumina supported catalysts keeps very high. On the other hand catalysts with a well‐defined Lewis acid character such as highly dispersed Zirconia on Silica allowed to obtain up to 64% yield in 2‐butyl‐furfuryl‐ether under the same conditions.

Influence of the Incorporation of Basic or Amphoteric Oxides on the Performance of Cu-Based Catalysts Supported on Sepiolite in Furfural Hydrogenation

“…Currently, there are several possible pathways to obtain valuable chemicals from FUR, and, among them, its selective hydrogenation to furfuryl alcohol (FOL) is the most important, since this is a relevant building block molecule for biofuels production and the manufacture of chemicals for resins, rubbers, and fibers [2][3][4]. FUR hydrogenation has been reported in vapor-phase using transition metals [2,4], liquid-phase using transition metals [5][6][7], and the catalytic transfer hydrogenation in liquid-phase in the presence of acid-base or metal sites [8][9][10][11][12].…”

Solid Acids for the Reaction of Bioderived Alcohols into Ethers for Fuel Applications

“…The effectiveness of Lewis acidity in promoting both reactions was confirmed using a copper supported catalyst, Cu/SiO 2 [78]. This catalyst possesses a peculiar Lewis acidic character based on the very high dispersion of the metallic phase, already exploited in the one-pot transformation of γ-valerolactone into valeric esters [79] and the cascade direct etherification of aromatic ketones with different alcohols [80].…”

“…The possibility to switch the selectivity towards different products based on the different acidic properties of the catalytic material used was also underlined by some authors by using ZrO 2 and SiO 2 -ZrO 2 in the reaction of furfural with 2-butanol under hydrogen transfer conditions ( Table 4, entries 15 and 16) [78]. Moving from ZrO 2 to SiO 2 -ZrO 2 under the same reaction conditions allowed the authors to respectively obtain 100% furfuryl alcohol or 87% of the ether by the genuine Lewis acid character shown by zirconia dispersed on silica, in agreement with the conclusions drawn by the use of Sn-Beta [74].…”

On demand production of ethers or alcohols from furfural and HMF by selecting the composition of a Zr/Si catalyst

“…Sn-and Zrbeta) are also reported. 25,29,32,[41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60] Alcohols are attractive compounds for CTH reactions being at the same time a solvent and a hydrogen-donor combined with their low cost, renewable nature and unique ability to participate in intra-and intermolecular hydrogen transfers. 9 The presence of an alcohol in the reaction medium also favors the etherification reaction which leads to a different class of interesting molecules.…”

“…Whereas the production of monoethers, which has been studied quite extensively, is far easier, [66][67][68][69][70][71][72][73] the diether synthesis is troublesome, involving a reduction step prior to etherification. 51,[74][75][76] The same applies for furfural, where the preparation of ethers requires the combination of a reduction step followed by the etherification of the resulting alcohol. [77][78][79] Some examples of the synthesis of furfuryl ethers and HMF diethers have been reported in the literature.…”