Scientists from the University of Surrey and their colleagues have produced non-metal electro-catalysts for fuel cells that could pave the way for production of low-cost, environmentally friendly energy generation.
In a study published in the Journal of Power Sources, the team from Surrey worked with colleagues from Queen Mary University of London to create low-cost carbon based electro-catalysts for anion-exchange membrane fuel cells (AEMFC). The catalyst helped to achieve a power density performance of 703 watts per square centimeter squared (mW cm-2) from the fuel cells—this compares to a performance of just 50 mW cm-2 from previous studies in this area.
The catalysts were made by using a cheap clay material called Halloysite as the template, urea as the nitrogen source and furfural (an organic chemical that can be produced from oats, wheat bran or sawdust) as the carbon source. This was then processed into a fine black powder and used as nitrogen-doped carbon electro-catalyst.
Compared with a benchmark Pt/C (20 wt%) catalyst, the as-prepared carbon catalysts demonstrated higher retention in diffusion limiting current density (after 3000 cycles) and enhanced methanol tolerances with only 50-60mV negative shift in half-wave potentials.
The project was supported by the Engineering and Physical Sciences Research Council’s SUPERGEN Hydrogen and Fuel Cell Hub.
Yaxiang Lu, Lianqin Wang, Kathrin Preuß, Mo Qiao, Maria-Magdalena Titirici, John Varcoe, Qiong Cai (2017) “Halloysite-derived nitrogen doped carbon electrocatalysts for anion exchange membrane fuel cells,” In Journal of Power Sources, Volume 372, Pages 82-90 doi: 10.1016/j.jpowsour.2017.10.037