Hydrogenation of Furfural with a Pt−Sn Catalyst: The Suitability to Sustainable Industrial Application Work from the Organic Reactions Catalysis Society Meeting 2016 A ́ ine O’Driscoll,* ,†,‡ Teresa Curtin, †,‡ Willington Y. Herna ́ ndez, § Pascal Van Der Voort, § and James J. Leahy †,‡ † Carbolea Research Group, Department of Chemical and Environmental Sciences, University of Limerick, Limerick, Ireland ‡ Material and Surface Sciences Institute, University of Limerick, Limerick, Ireland § Department of Inorganic and Physical Chemistry, Center for Ordered Materials, Organometallics and Catalysis (COMOC), Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium *S Supporting Information ABSTRACT: The liquid-phase hydrogenation of furfural to furfuryl alcohol was carried out using a Pt−Sn/SiO 2 catalyst synthesized by coimpregnation to investigate the impact of synthesis and reaction conditions. The results showed that calcination of the catalyst at 450 °C gave the highest furfural conversion. An investigation on the reaction conditions found that furfural conversion increased with temperature and hydrogen pressure. Reuse of the catalyst was shown to be as effective as catalyst regeneration with a 3% loss in furfural conversion observed with each repeated use. The use of protic and aprotic solvents showed that furfural conversion was lower using an aprotic solvent such as toluene or propanone, but selectivity to furfuryl alcohol remained close to 100%. The two protic solvents, 1-propanol and 2-propanol, formed several additional products including 2-methyl furan, 2-propoxy methyl furan, 2-furaldehyde dipropyl acetal, difurfuryl ether, and 2-furaldehyde diethyl acetal. ■ INTRODUCTION The level of fossil fuels is diminishing, and energy demands are continuing to rise. Biomass is currently the only renewable source of carbon, and this has led to increased interest and research in its potential for chemicals, energy, and fuel production. The necessity to substitute the energy demands currently satisfied by fossil fuels with biomass derived materials is aided by directives such as the Renewable Energy Directive (RED). This directive requires EU members to fulfill at least 20% of total energy needs and 10% of transport needs with renewables by 2020. 1 Additional projects such as the European Sustainable Process Industry (SPIRE) initiative also support fossil energy substitution. SPIRE is a public-private partnership which aims to reduce fossil energy intensity by 30% coupled with a 20% reduction in the use of nonrenewable resources by 2030 (SPIRE 2013). 2 The increase in biomass utilization, as a result of participation in such initiatives, has augmented research and development of alternative biobased routes for the production of fine chemicals from biomass sources. Furfural (FF), which is obtained from the C5 sugars in lignocellulosic biomass, is a platform chemical which may be further processed to produce furfuryl alcohol (FA), furan, tetrahydrofurfural, and tetrahydrofurfuryl alcohol among others. 3 The desired product, furfuryl alcohol, is formed by the catalytic hydrogenation of furfural; however, selective hydrogenation is necessary due to the array of possible furfural derivatives. This process requires careful catalyst selection together with the optimization of the reaction conditions to ensure maximum economical product delivery. The industrial catalyst for the hydrogenation of furfural to furfuryl alcohol is copper chromite and is well-known to be environmentally toxic, promoting extensive research to develop suitable alternatives. 4 Green chemistry for industry addresses all aspects of the manufacturing process to promote industrial environmental sustainability. Bourne et al. 5 highlighted 12 principles of industrial green chemistry which include prevention of wastes and use of ambient temperature and pressure together with using a reduced number of steps in a process. The disposal of solvents from reactions and purification processes account for the bulk of industrial waste. These principles underpin this work by targeting furfuryl alcohol as the sole product and maintaining the single step process of furfural hydrogenation. The ability to reuse a catalyst is a necessity for an economical process. Catalysts may deactivate over time, and generally, regeneration of the catalyst is required. Several techniques are used to achieve this with the regeneration technique applied based on the cause of deactivation. 6 The most common technique employed for the extraction of organics from a solid catalyst matrix at laboratory scale is Soxhlet extraction. It has been used effectively for over a century and is often used as the benchmark. 7 There are some issues with Soxhlet extraction as it is energy demanding and time-consuming. An alternative method is ultrasound assisted extraction using a sonicator. This method significantly reduces the process duration and further reduces the quantity of solvent required. An additional important factor is the ability to conduct the process at room temperature. 8,9 Received: June 30, 2016 Published: October 14, 2016 Article pubs.acs.org/OPRD © 2016 American Chemical Society 1917 DOI: 10.1021/acs.oprd.6b00228 Org. Process Res. Dev. 2016, 20, 1917−1929