(617dw) Contributions of Heterogeneous Catalysis to Renewable Energy: an Electrochemical Perspective

Nowadays, research in sustainable energy sources has received considerable attention. Residual biomass is considered a potential source of neutral carbon that can be transformed into biofuels, mainly for transportation and chemicals production, through thermochemical processes for the generation of chemical precursors (ketones, acids, alcohols, furan compounds) which are characterized by high oxygen content [1]. One of the technological issues of lignocellulosic biomass is its structural configuration who has hydrophilic character and high oxygen content, that causes a decrease in the heat capacity and generates corrosion, being necessary to remove oxygen and increase the H/C ratio [2]. An alternative to these problems is use heterogeneous catalysts which are more selective, stable and environmentally friendly, in terms of biomass conversion. In example, HMF and furfural are very versatile chemical precursors of liquid fuels through a series of processes including dehydration, condensation and hydrogenation reactions. The aldol compounds are transformed into a mixture of linear hydrocarbons C₉ - C₁₅, using bifunctional metal catalysts [3]. Bioethanol as fuel in direct fuel cells, which is produced from biomass as a waste product from biorefineries is also a good example of transforming lignocellulosic biomass into chemical energy or electrical energy [4]. The breaking of the C-C is the rate determining step in the mechanism of electrooxidation, being the palladium metals the most active for the oxidation of alcohols under basic metal together with, Sn and Ru. These are only few examples.

In this work the high contributions from the catalysis (in this case Pd, Sn and Ru) for the electrooxidation of bioethanol to obtain electricity is well discussed and supported on experimental data including the synthesis, characterization and the fuel cell evaluation. It is shown how through catalysis it is possible to produce energy at high quality using hydrated ethanol that is cheaper in the market.

References

[1] K. S. Triantafyllidis, A. A. Lappas, M. Stcker. The role of catalysis for the sustainable production of bio-fuels and bio-chemicals. First edition 2013 Elsevier.

[2] P. Mäki-Arvela, T. Salmi, B. Holmbom, S. Willför, D.Y. Murzin, Synthesis of sugars by hydrolysis of hemicelluloses. A review, Chem. Rev. 111 (2011

[3] Sudipta De, Basudeb Saha, Rafael Luque. Hydrodoxigenation processes: Advanced on catalityc transformation of biomass-deriveted plattform chemicals into hydrocarbon fuels. Bioresource Technology. 178 (2015) 108â??118

[4] ]. R. M. Modibedi, T. Masombuka, and M. K. Mathe, â??Carbon supported Pdâ??Sn and Pdâ??Ruâ??Sn nanocatalysts for ethanol electro-oxidation in alkaline medium,â? International Journal of Hydrogen Energy, vol. 36, no. 8, pp. 4664â??4672, Apr. 2011