Hydrotalcites are anionic clays which have a variety of applications, including use as environmentally friendly catalysts and catalyst precursors. In this experiment we propose to ue POLARIS to study in situ the formation, dehydration and calcination of two representative hydrotalcites with Mg:Al ratios of 0.15 and 0.3. These materials will be prepared as they would in a typical precipitation reaction, and we would like to use POLARIS to follow the entire process in situ to allow us to monitor the formation of the hydrotaclites, subsequent water loss and and also the calcination to mixed metal oxides. We anticiapte that the data will allow us to identify the relevant phases and timescales, and crystallinity. We will conduct post mortem analysis of the samples via for example surface and thermal techniques and SEM.