Biomass Derived Chemicals: Furfural Oxidative Esterification to Methyl-2-furoate over Gold Catalysts

Abstract

Abstract:The use of heterogeneous catalysis to upgrade biomass wastes coming from lignocellulose into higher value-added chemicals is one of the most explored subjects in the prospective vision of bio-refinery. In this frame, a lot of interest has been driven towards biomass-derived building block molecules, such as furfural. Gold supported catalysts have been successfully proven to be highly active and selective in the furfural oxidative esterification to methyl-2-furoate under mild conditions by employing oxygen as benign oxidant. Particular attention has been given to the studies in which the reaction occurs even without base as co-catalyst, which would lead to a more green and economically advantageous process. The Au catalysts are also stable and quite easily recovered and represent a feasible and promising route to efficiently convert furfural to methyl-2-furoate to be scaled up at industrial level.

New Frontiers in the Catalytic Synthesis of Levulinic Acid: From Sugars to Raw and Waste Biomass as Starting Feedstock

“…Catalysts 2016, 6,196 15 of 29 pathway for the acid-catalyzed hydrolysis of the cellulose and hemi-cellulose fraction of the water hyacinth, as shown in Figure 7. Another yet almost unexplored biomass for the production of LA is represented by algae.…”

“…One of the greatest challenges that industry faces in the 21st century is the transition from a fossil fuel based economy to one based on renewable resources, driving the search of new alternative renewable feedstocks for the production of chemical building blocks [1][2][3][4][5][6]. In particular, the exploitation of lignocellulosic biomass is receiving an increasing attention due to its renewability, abundance, low value and carbon-neutral balance.…”

“…Catalysts 2016, 6,196 5 of 29 levulinic acid [13,47,[50][51][52], in addition to the several important compounds obtained from their upgrading, such as 2-methyltetrahydrofuran, hydrocarbon fuels, valerate esters and polymers [49]. The development of new LA-derived products is continuously in progress, alongside LA production at larger scale.…”

New Insights on the Dynamic Role of the Protecting Agent on the Reactivity of Supported Gold Nanoparticles

“…However, in view of process intensification, cost reduction and low environmental impact, heterogeneous catalysts would be the most advisable choice. Supported gold nanoparticles have proved to be extremely active in 2‐FA esterification (Scheme ), under mild conditions by employing O 2 as benign oxidant and even without the use of a base (CH 3 ONa or K 2 CO 3 ) to enhance the catalysis therefore making the process sustainable from both environmental and economic points of view …”

“…[5,6] However, in view of process intensification, cost reduction and low environmental impact, heterogeneous catalysts would be the most advisable choice. Supported gold nanoparticles have proved to be extremely active in 2-FA esterification (Scheme 1), under mild conditions by employing O 2 as benign oxidant and even without the use of a base (CH 3 ONa or K 2 CO 3 ) to enhance the catalysis [7][8][9][10] therefore making the process sustainable from both environmental and economic points of view. [11] The strong dependence of the activity on the Au size, firstly described on Au/ZrO 2 , was attributed to the presence of Au clusters supported on zirconia that dissociate O 2 and produce atomic O able to activate CH 3 OH.…”