What to do with CO₂? Towards valuable chemicals using plasma and catalysis

This thesis describes different ways of converting CO₂ to high value-added chemicals. For that, we tested traditional (γ-Al₂O₃, TiO₂ and MgO based catalysts) and non-traditional (MAX phase and MXene based catalysts) materials in different thermocatalytic reactions: butane dry reforming (where CO₂ reacts with butane to produce syngas), reverse water-gas shift (RWGS, where CO₂ reacts with H₂ to CO and H₂O), and butane oxidative dehydrogenation (ODH) to produce butenes. In addition to thermal-catalysis, we used plasma-catalysis to perform CO₂ splitting and CO₂ hydrogenation to methanol. Overall, we found that Ti-based MAX phases are promising supports for CO₂ conversion reactions due to their stability, acidity and electronic properties. We have also shown that MXenes are promising catalysts in redox reactions due to their electronic properties and their ability to stabilise vacancy sites. Regarding plasma-enhanced catalysis, we have seen that metal oxide supported catalysts are able to improve CO₂ conversion and tune the selectivity in a DBD plasma setup, near ambient temperature and pressure. The metal loading and the metal oxide dispersion played important roles during CO₂ hydrogenation. Similar materials had no catalytic effect during CO₂ splitting in RF plasma. Nevertheless, we found that metal meshes can also act as catalysts under these conditions, increasing the CO yield.