This improvement is crucial for the larger adoption of fuel cells in numerous applications, including transport and power generation, as part of the worldwide shift towards sustainable energy sources.Caffeine enhances fuel cell performance by improving the activity of the oxygen reduction reaction.Amidst worldwide efforts to move away from fossil fuels, fuel cells emerge as a noteworthy source of energy without carbon emissions. The fuel is fed to the anode, and an oxidizing agent, typically oxygen from the air, is provided to the cathode.In a hydrogen fuel cell, hydrogen undergoes oxidation at the anode, producing hydrogen ions and electrons. To preserve efficient operation, fuel cells need a high Pt loading, which substantially increases the expenses of fuel cells.Adsorbed structure of caffeine on well-defined Pt single crystal electrodes and the activity of air electrode of fuel cell before (blue bar) and after (orange bar) caffeine adjustment. Conversely, for Pt( 100 ), the impact of reducing PtOH was counteracted by the steric obstacle of the adsorbed caffeine, and therefore caffeine did not affect the ORR activity,” describes Prof. Hoshi.Unlike batteries with minimal life expectancies, fuel cells can produce power as long as fuel is provided, making them ideal for various applications, consisting of cars, structures, and space objectives.
Scientists at Chiba University have found that including caffeine to the platinum electrodes of fuel cells can substantially enhance their performance by enhancing the oxygen reduction response. This advancement has the potential to lower the platinum requirements, therefore making fuel cells more cost-effective and efficient. This development is essential for the larger adoption of fuel cells in different applications, consisting of transportation and power generation, as part of the worldwide shift towards sustainable energy sources.Caffeine improves fuel cell performance by increasing the activity of the oxygen reduction reaction.Amidst around the world efforts to move away from nonrenewable fuel sources, fuel cells become a noteworthy source of energy without carbon emissions. These cells are made up of a cathode and an anode, divided by an electrolyte, and they straight transform the chemical energy of the fuel into electrical power. The fuel is fed to the anode, and an oxidizing agent, typically oxygen from the air, is supplied to the cathode.In a hydrogen fuel cell, hydrogen goes through oxidation at the anode, producing hydrogen ions and electrons. The ions move through the electrolyte to the cathode, and electrons circulation through an external circuit, producing electrical energy. At the cathode, oxygen combines with the hydrogen ions and electrons, leading to water as the sole byproduct.However, the existence of water impacts the efficiency of the fuel cell. It responds with the platinum (Pt) catalyst, forming a layer of platinum hydroxide (PtOH) on the electrode, which blocks the effective catalysis of the oxygen decrease reaction (ORR), causing energy losses. To maintain effective operation, fuel cells require a high Pt loading, which considerably increases the costs of fuel cells.Adsorbed structure of caffeine on distinct Pt single crystal electrodes and the activity of air electrode of fuel cell before (blue bar) and after (orange bar) caffeine modification. Credit: Professor Nagahiro Hoshi from Chiba UniversityBreakthrough in Fuel Cell Catalyst EfficiencyNow, in a study recently published in the journal Communications Chemistry, Professor Nagahiro Hoshi, in addition to Masashi Nakamura, Ryuta Kubo, and Rui Suzuki, all from the Graduate School of Engineering at Chiba University, Japan, have discovered that including caffeine to certain platinum electrodes can increase the activity of the ORR. This discovery has the possible to decrease platinum requirements, making fuel cells more efficient and budget friendly.”Caffeine, among the chemicals included in coffee, enhances the activity of a fuel cell response 11-fold on a distinct Pt electrode of which atomic plan has a hexagonal structure,” states Prof. Hoshi.The Impact of Caffeine on Platinum ElectrodesTo evaluate caffeines effect on the ORR, scientists measured existing flow through platinum electrodes immersed in an electrolyte containing caffeine. These platinum electrodes had actually surface atoms set up in particular directions, namely (111 ), (110 ), and (100 ). There was a significant improvement in the electrodes ORR activity with a boost in caffeine concentration in the electrolyte. Caffeine, when present, adsorbs onto the electrodes surface area, efficiently preventing hydrogen adsorption and the formation of Pt oxide on the electrode. However, the result of the caffeine depended upon the orientation of the platinum atoms on the electrodes surface.At a caffeine molar concentration of 1 × 10 − 6, the ORR activity on Pt( 111) and Pt( 110) increased by 11 and 2.5 times, respectively, without any visible impact on Pt( 100 ). To comprehend this difference, the researchers investigated the molecular orientation of caffeine on the electrode surface using Infrared Reflection Absorption Spectroscopy. They discovered that caffeine gets soaked up on Pt( 111) and Pt( 110) surfaces with its molecular plane perpendicular to the surface area. However, on Pt( 100 ), steric barriers cause it to be connected with its molecular aircraft tilted relative to the surface of the electrode.”The increased ORR activity of Pt( 111) and Pt( 110) was credited to the decreased PtOH protection and lower steric barrier of the adsorbed caffeine. On the other hand, for Pt( 100 ), the effect of reducing PtOH was counteracted by the steric hindrance of the adsorbed caffeine, and thus caffeine did not impact the ORR activity,” discusses Prof. Hoshi.Unlike batteries with restricted life-spans, fuel cells can generate power as long as fuel is provided, making them appropriate for different applications, including automobiles, buildings, and area objectives. The proposed method has the potential to enhance the styles of fuel cells and result in their extensive use.Reference: “Enhanced oxygen decrease reaction on caffeine-modified platinum single-crystal electrodes” by Nagahiro Hoshi, Masashi Nakamura, Ryuta Kubo and Rui Suzuki, 3 February 2024, Communications Chemistry.DOI: 10.1038/ s42004-024-01113-6The research study was moneyed by the New Energy and Industrial Technology Development Organization.
