Outreach

In the article "external page A Bio-Inspired Dendritic MoO_x Electrocatalyst for EfficientElectrochemical Nitrate Reduction to Ammonia" published in Advanced Energy Materials we take inspiration from biologic processes handling nitrate in nature and develop a material consisting of the two elements molybdenum and oxygen to convert nitrate into ammonia with the help of electricity.

Nitrate is a molecule which originates majorly from the fertilization of plants. In general, nitrate is essential for the growth of plants and crops. However, a large portion of this molecule is not used by the desired crops, but instead spread in the environment leading to the explosive growth of other unwanted plants. Since nitrate itself is also dangerous to human health, especially of infants, and causes an imbalance of plants in nature, which in turns results in the death of animals and other plants, it is important to remove the excess of nitrate from the environment and hence restore harmony and balance in biological systems. Ammonia on the other hand is an essential molecule for humanity nowadays, since it does not only play a key role in fertilizers, but also in the production of chemicals and is seen as a possible energy carrier for the future.

In our study we show that the activity and effectivity of our material remains constant for over 4 months, after which the experiment was stopped. In addition, our material produces in optimized conditions up to 99% of ammonia as the desired molecule with nearly no other by-product. Furthermore, the rate at which nitrate were converted into ammonia happened on a scale interesting for industrial applications. In-depth analysis has also suggested, that in spots in the molybdenum-oxygen network, at which an oxygen atom was missing, the nitrate molecule might be attracted stronger to the material and converted much easier than in spots where no oxygen was missing.