In our laboratory we are currently bringing a new UHV setup to production. We will present this setup which enables us to reach conditions similar to those present in dense molecular clouds (T = 10 K, ρN = 105 cm-3). In combination with our laser ablation setup, which we use to produce realistic carbonaecous and silicate dust analoga, we will use the UHV setup to study the chemical interactions and chemical evolution of ices deposited on dusts, which resembles the icy grains in molecular clouds, under irradiation with Lyman α light. Furthermore, photostability mass spectrometical measurements of some species deposited on silicate dusts under irradiation with Lyman α light were studied, expanding the experiments in photodesorption to interactions with dusts. So far the chemistry of irradiated ices and photodesorption has only been studied on ideal substrates (McMurtry/Kaiser2010, Bertin/Linnartz2016, Kaiser/Mathies2010) but erosion of dusts under irradiation has been observed. Therefore we suppose that investigations of ices on dusts is crucial for understanding interstellar chemisty. In this poster we present our developed setup, quantum chemical results on ice/dust interactions and first experimental results.