FULL PAPERS
DOI: 10.1002/adsc.200900526
Selective Hydrogenation of 5-Ethoxymethylfurfural over
Alumina-Supported Heterogeneous Catalysts
Erik-Jan Ras,a,b Sergio Maisuls,a Paul Haesakkers,a Gert-Jan Gruter,a,*
and Gadi Rothenbergb,*
a
Avantium Technologies B.V., Zekeringstraat 29, 1014BV Amsterdam, The Netherlands
Fax : (+31)-(0)20-586-8085; phone: (+31)-(0)20-586-8080; e-mail: gert-jan.gruter@avantium.com
Van ꢀt Hoff Institute of Molecular Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam,
b
The Netherlands
Fax : (+31)-(0)20-525-5604; phone: (+31)-(0)20-525-6963; e-mail: g.rothenberg@uva.nl
Received: July 29, 2009; Published online: November 24, 2009
Abstract: We report here the synthesis and testing of conversion and product selectivity are sensitive to-
a set of 48 alumina-supported catalysts for hydroge- wards temperature changes and solvent effects. The
nation of 5-ethoxymethylfurfural. This catalytic reac- best results of >99% yield to the desired product, 5-
tion is very important in the context of converting ethoxymethylfurfuryl alcohol, are obtained using an
biomass to biofuels. The catalysts are composed of iridium/chromium (Ir/Cr) catalyst. The mechanistic
one main metal (gold, copper, iridium, nickel, palla- implications of different possible reaction pathways
dium, platinum, rhodium, ruthenium) and one pro- in this complex hydrogenation system are discussed.
moter metal (bismuth, chromium, iron, sodium, tin,
tungsten). Using a 16-parallel trickle-flow reactor,
we tested all 48 catalyst combinations under a varie- Keywords: bimetallic catalysts; biomass conversion;
ty of conditions. The results show that both substrate furfural; iridium; parallel flow reactors
Introduction
7% of the available biomass to chemicals and
energy).
In 2008, crude oil prices peaked at over $140 per
The problem is that biomass is chemically very dif-
barrel, promoting a surge of activity towards finding ferent from crude oil. Crude oil is composed of hydro-
renewable energy solutions. While the price of crude carbons, most of which are unfunctionalized. Biomass,
oil has abated somewhat with the financial crisis that on the other hand, is typically over-functionalized. It
followed, long-term availability prognoses remain pes- is a mixture of alcohols, ethers, esters, and carboxylic
simistic. Indeed, regardless of whether we have al- acids. Thus, catalytic refining of biomass presents dif-
ready passed the so-called ꢀpeak oilꢁ point or not, the ferent, and often yet unmet, challenges. Previously,
move towards renewable feed stocks will have to be we have studied various catalytic options for valoriz-
made in our lifetime. Much work is being done in sev- ing fatty acids,[5] triglycerides,[6] and glycerol deriva-
eral parallel fields, including harnessing solar,[1] tives.[7] Here, we focus on furfural derivatives, which
wind,[2]and geothermal power,[3] developing safer nu- can be obtained from cellulose, starch, hemicellulose
clear technologies,[4] and refining biomass.[5,6] Of and sugars.[8] Specifically, we study the catalytic con-
these, biomass refining is the most readily applicable version of 5-ethoxymethylfurfural 1 to 5-ethoxyme-
on a large scale worldwide. This is because the cur- thylfurfuryl alcohol 2 (Scheme 1). This unsaturated al-
rent energy market is a conservative one, with compa- cohol is a potential additive for diesel fuel. Its com-
nies looking first and foremost for pragmatic solu- bustion profile is similar to that of ethanol, yet its
tions. Changing from one energy source to another miscibility in diesel is much higher. We synthesized
often requires new and costly infrastructures. In this and tested a set of 48 bimetallic catalyst combinations
respect, biomass conversion is less problematic than supported on g-alumina, and tested their activity and
hydrogen energy, for example, since much of the ex- selectivity in this hydrogenation reaction.
isting infrastructure can be used. Moreover, there is
ample biomass available (we convert today less than
Adv. Synth. Catal. 2009, 351, 3175 – 3185
ꢂ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
3175