The goal
Dust grains in the ISM are mainly composed by silicates and carbonates, but they also contain an important amount of transition metal inclusions which are well know to act as catalysts on Earth. While the chemistry of the ices that surround dust grains is usually studied, catalytic processes are not contemplated, even if they could be an important source for the evolution of chemical complexity. We aim to study the reactivity of these metallic inclusions under different astrophysical conditions in order to understand what is their role on promoting chemical evolution during the process of star and planetary formation.
The experimental procedure
We will produce catalytic systems of different transition metals, mainly Fe, Ni, Cr and Co, which are generally assumed to be present in dust grain components, and form through space weathering processes. We will deposit them on a Cu surface coated in silica and characterise their growth and chemical composition using RAIRS, TDP and TEM-EDX.
We will introduce our catalytic systems in the UHV rigs and expose them to different conditions of temperature, pressure and gas composition according to different evolutionary stages during the star formation process: the solar nebula, the protoplanetary disk and primordial protoplanetary atmospheres. We will explore thermally and photocatalytic driven synthesis of small molecules which are relevant to interstellar environments. We will focus on the primordial chemistry of H2, CO and N2, but we will also explore the far less studied chemistry of S and P. The interaction of the reactants with the surface and its evolution during the reaction will be measured in situ, as well as the products synthesised, using RAIRS, XPS and QMS.
In parallel, our studies will be complemented by computational studies which will develop atom-based structural models of the catalytic systems and explore the potential energy surfaces for the observed reactions in full details.
The results
This is our newest project, started on July 2022, so there are no results to show, just yet. Stay tuned!
links and publications
