Aplicaciones de la espectroscopia FTIR para la electroxidación de etanol. Efectos del pH y de la naturaleza del catalizador

Abstract

Uno de los mayores problemas que ha de afrontar con urgencia la sociedad actual es el cambio climático. En su mayor parte, este cambio se debe al modelo de progreso económico y tecnológico de la sociedad, sostenido principalmente por el uso de combustibles fósiles como fuente de energía. El actual modelo energético está basado en la combustión de dichos combustibles fósiles, es decir el carbón, el petróleo y el gas natural, lo que conlleva la emisión de gases de efecto invernadero además de otros contaminantes nocivos (óxidos de nitrógeno, óxidos de azufre, partículas, etc). Este tipo de fuentes de energía, además de ser contaminantes, tienen un problema añadido y es que son finitas, es decir, eventualmente se agotarán. Esto genera y generará conflictos geopolíticos con el fin de asegurar el suministro de estas fuentes de energía. Es por ello que la transformación de este modelo despierta un gran interés social hoy en día. Dicha transformación pasa por una decarbonización de la economía, apoyada en la implantación de las energías renovables y limpias (sin emisiones de gases de efecto invernadero) capaz de garantizar el nivel de servicios que necesita la sociedad para su desarrollo. Se espera que a medio plazo las energías renovables puedan ser dominantes en ciertos sectores como el del transporte por carretera, uno de los mayores emisores de CO2 a la atmósfera.

[EN] One of the biggest problems the current society has to urgently face is climate change. This change is mostly due to the economic and technological progress model of society, which is mainly maintained by the use of fossil fuels as energy sources. The current energetic model is based on these fossil fuels (that is, coal, petrol and natural gas), which leads to the emission of greenhouse gases and other toxic pollutants. Apart from being contaminating, this sort of energy sources have an added problem: they are finite and, so that, we are running out of them. This fact undoubtedly generates and will generate geopolitical conflicts with the aim of ensuring the supply of the before-mentioned energy sources. At this point, the transformation of the current energetic model becomes a topic of great social interest nowadays. It is our mission to transform the economy into the one based on renewable energies, which permit both the generation of clean energy (without greenhouse gases emissions) and the decarbonisation of society. It is expected that renewable energies are dominant in the medium term in certain sectors, such as road transport, one of the leading emitters of CO2 to the atmosphere. Both the EU and diverse worldwide energetic agencies have identified electrochemical technologies as the ones with more potential to achieve the decarbonisation of the energetic sector through its electrification. Between the electrochemical technologies of interest we found batteries, electrolysers and fuel cells. The latter are devices that generates electric work facing two reactions, one of oxidation and one of reduction. Ethanol is ideal for fuel cells because of its high energetic density. It is not toxic, it is easily storable and transportable, and it can be obtained from lignocellulosic residues, which makes ethanol a fuel of second generation. In a fuel cell fed by ethanol (DEFC), ethanol oxidizes in the anode in the presence of an electrocatalyst. In this context, the studies about ethanol electrooxidation reaction and the design of catalysts highly active and effective are of great relevancy currently.