(310a) Valorisation of Mining Residues for Direct CO2 Hydrogenation

Direct CO₂ hydrogenation combines in a single step the reduction of CO₂ to CO and the reverse water-gas-shift reaction (RWGS). This process arouses great interest for its role in the reduction of CO₂ emissions, the production of synthetic fuels and space exploration.

The use of synthetic liquid hydrocarbons requires no significant changes to the existing infrastructure and engines, because they can be processed to fit the current specifications. Direct hydrogenation of CO₂ (the main greenhouse gas) for the production of synthetic fuels does not require a gasification step, in addition to being more economical and environmentally friendly.

In this work several catalytic formulations, prepared from mining residues and doped active components such as ceria, zirconia and potassium have been chosen to be tested. These multifunctional catalysts provided more than 1 types of active sites, which play a synergetic role in the catalytic conversion of CO₂. The selectivity of the process in long carbon chains such as petrol, diesel and waxes, similar to those produced from fossil fuels, has been evaluated as function of the test conditions. Mechanistic understanding of the catalyst/support interactions gained from XRD and SEM analyses guided the tuning of the surface properties and provide insight towards maximizing yields.