Fuel cells are devices designed to directly transform the chemical energy of a fuel into electrical energy, without the combustion step necessary for the operation of all the endo and exothermic engines used today. Saving one step, in addition to making the energy production process more efficient, avoids or limits the production of some substances (including CO2) with a strong environmental impact. Therefore, from the perspective of the green transition, fuel cells are considered interesting alternatives for the production of electricity on both large and small scales.
Among the many types of fuel cells studied, the type that runs on alcohol today receives particular interest due to an important series of technological factors. These cells use liquid fuel, which makes them easier to operate than the more famous hydrogen cells which use high pressure hydrogen. Direct alcohol cells can also work at room temperature while maintaining a reasonable level of efficiency, unlike most other types of fuel cells which have operating temperatures between 50 and 200°C. These factors contribute to greatly simplifying the complexity of alcohol devices, which will need a limited number of ancillary systems to work efficiently, therefore lending themselves very well for small off-grid applications, or for powering portable devices. Also with regard to fuel management, the alcohol used can be obtained from the processing of some waste biomass, while for some systems the exhausted liquids can be purified and reprocessed to obtain valuable chemical products for the industry, all following a virtuous logic in where waste is minimised.>
On the other hand, there are still numerous technical challenges that must be overcome to reach the commercialization of these devices. The major obstacles to overcome are related to the development of catalysts for the oxidation reactions of alcohols based on elements that are not critical for the world market, which can also have constant efficiency over time. More generally, there are many fundamental and practical issues related to materials science that still need to be addressed to make these devices an attractive alternative for widespread use.
A review entitled “Direct Alcohol Fuel Cells: A Comparative Review of Acidic and Alkaline Systems” (DOI: 0.1007/s41918-023-00189-3) was recently published in Electrochemical Energy Reviews (Impact Factor 31.2 Journal Citation Report (Clarivate Analytics, 2023)). This review is the result of a joint effort by some of the most important Italian and foreign experts on the topic, which aims to take stock of the state of the art of this technology, highlighting some of the critical issues for its future development, and describing the solutions that the present generation of scientists is implementing to circumvent them. This review work was carried out by Dr. Carlo Santoro (Department of Materials Science – University of Milano - Bicocca) jointly with Enrico Berretti, Hamish A. Miller, Jonathan Filippi, Francesco Vizza e Alessandro Lavacchi (CNR-ICCOM, Istituto per la chimica dei composti organometallici), Luigi Osmieri ( Los Alamos National Laboratory), Vincenzo Baglio (CNR-ITAE , Istituto di tecnologie avanzate per l’energia “Nicola Giordano”), Monica Santamaria (Università di Palermo) and Stefania Specchia (Politecnico di Torino).