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MXenes are a new family of 2D carbides or nitrides that have attracted attention due to their layered structure, tunable surface groups and high electrical conductivity. Here, we report for the first time that Ti 2 CT x MXene catalyses the selective oxidative dehydrogenation of n -butane to butenes and 1,3-butadiene. This catalyst showed higher intrinsic activity compared to commercial TiC and TiO 2 samples in terms of C 4 olefin formation rate. We propose that the stabilisation of structural vacancies and the change in composition (from a carbide to a mixed phase oxide) in the MXene causes its higher catalytic activity. These vacancies can lead to a higher concentration of unpaired electrons in the MXene-derived material, enhancing its nucleophilic properties and favouring the production of olefins. We thank the Netherlands Organization for Scientific Research (NWO) for the grant “Developing novel catalytic materials for converting CO2, methane and ethane to high-value chemicals in a hybrid plasma-catalytic reactor” (China.15.119). EVRF thanks the “Ministerio de Ciencia e innovación” grant (PID2020-116998RB-I00).

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.