Throughout history, there are many legends that consist of alchemists turning lead into a much more valuable metal - gold. Researchers at Brown University have gained insight on turning a modern version of the legend into reality. This article explores the prospective use of miniscule gold particles as catalyst to convert the detrimental and abundant carbon dioxide particles from the atmosphere into carbon monoxide, a rather advantageous molecule. While carbon dioxide is a detrimental greenhouse gas that is drastically increasing the average temperature of the earth, carbon monoxide on the other hand can be utilized for the production of synthetic natural gas, alternative fuels, methanol and commodity chemicals.
The conversion of a carbon monoxide molecule from a carbon dioxide one is a fascinating yet difficult process due to the extreme stability of the carbon dioxide molecule. Previous research indicates ...view middle of the document...
Furthermore, these results were perplexing, as shrinking the particle size appeared to make the reaction more efficient; however sizes below eight nanometers were unfavourable to the conversion rate. Using an advanced modelling method called Density Functional theory, it was found that the shapes of the nanoparticles at different sizes played vital role in their catalytic properties. Andrew Peterson, professor of engineering at Brown University explains: “when you take a sphere and you reduce it to smaller and smaller sizes, you tend to get many more irregular features – flat surfaces, edges, and corners (Brown University 2013)". Upon analysis, it was discovered that the active sites required for the specific conversion are edge sites, while the corner sites created the hydrogen by-product. By reducing the size of the particles, the activity is optimized due to a greater number of edge sites and a lower number of corner sites. However, by reducing the size to less than eight nanometers, a shrinkage of edge sites occurs which leaves more corner sites. The researchers are still researching to find ways to enhance the nanoparticle. They expect these findings to be a sustainable feedstock for recycling carbon dioxide for large scale commodity chemicals.
Personally, I believe that this study is very beneficial not only economically, but environmentally as well. The conversion of carbon dioxide to carbon monoxide not only allows us to dissipate a detrimental greenhouse gas, but also allows us to synthesize molecules that produce alternative fuels and commodity chemicals. The process of using gold nanoparticles instead of bulk metal catalyst also helps conserve gold, and reduces cost as well. This study also allowed scientists to see how specific parts of a catalyst may be more active and partial to synthesize different products. This is very useful for the future optimization of catalyst by manipulating the catalyst sites to produce desired products. As a result two birds can be hit with the same stone: humanity's ample supply of a greenhouse gas and our need for larger fuel sources.