Ripping water apart into hydrogen and oxygen can form the basis of artificial photosynthetic devices. These devices potentially can power homes and businesses, and car manufacturers will be able to start massive production of hydrogen-powered vehicles.
However, catalysts for this type of reaction are either effective but expensive and unstable, or are affordable, stable, and ineffective. The task of finding the middle ground or the best of these two types was undertaken by a group of researchers. Finally, they were able to find the needed catalyst. They published a report in ACS Central Science that they found a catalyst that is really the best of two words.
Usually, for the process of water splitting two types of catalysts were used. The first one is “homogeneous”. It dissolves into the reaction solution and it is usually active and selective. However, it doesn’t work in some applications due to its cost and instability. On the other hand, the second type, “heterogeneous” catalysts, is solid that is stable, recyclable and convenient to work with, but not very active or selective. According to researchers, producing a hybrid material will get them closer to the ideal catalyst.
They used iridium dinuclear heterogeneous catalysts (DHCs), attached to a tungsten oxide substrate, to create a new hybrid catalyst. The key moment was attaching the ends of DHC molecules, instead of the sides. It allowed the catalyst to perform optimally and to increase the effectiveness of water splitting. The researchers suggest that this first-of-its-kind material could be an important step toward alternative solar energy storage or artificial photosynthesis.
“As such, the results represent an important step toward tailor-designed, atomically defined heterogeneous catalysts for important chemical transformations such as solar fuel synthesis.”
The authors acknowledge funding from the National Science Foundation and the Department of Energy.
You can read the full paper here: https://pubs.acs.org/doi/full/10.1021/acscentsci.8b00335