With more than 60% of greenhouse gas emissions produced by the energy sector, increased efforts are required to meet the 2050 climate goals established by the European Union (EU) to become the world’s first climate-neutral continent, as energy demand is not anticipated to decline. Moreover, while the transition to renewable energy will extensively contribute to lowering such emissions, CO2 sources from certain power and process industries will likely persist in the long term. Recent initiatives developed by the European Commission are specifically focussing on CO2 chemical valorisation, aiming to convert CO2 into various useful products, including chemicals and fuels. Specifically, conversion by hydrogenation of excess CO2 would potentially decrease emissions related to chemical feedstock synthesis by ∼90% compared to current industrial solutions. In this context, converting CO2 to methanol (MeOH), a widely applicable component for fuels, plastics, paints, and textile chemicals, is gaining significant interest for industrial implementation, owing to its significant economic potential. However, the major challenge related to the process is the low performance, mainly caused by limited catalyst selectivity and deactivation caused by active metal nanoparticles (NP) sintering.
MEXCAT aimed at developing new stable and selective catalysts for the efficient catalytic CO2 hydrogenation to MeOH, employing the novel method of NP “exsolution”, where catalytic nanoparticles are generated in situ from an active metal-substituted oxide. Subjecting this tailor-designed material to a thermal reduction causes metal ion diffusion to the oxide surface, subsequently nucleating or “exsolving” into anchored, and hence highly stable, nanoparticles. Although several literature examples reported the successful use of exsolved materials for catalytic applications, the exsolution pathway had barely been explored for the catalytic CO2 hydrogenation to MeOH. Building upon the proven compositions of state-of-the-art catalysts for this hydrogenation reaction, the project aimed at designing and synthesising novel exsolved materials as next-generation catalysts for the CO2 hydrogenation to MeOH, to reach the ambitious goal of a 10% MeOH yield. To then address the knowledge gap in the understanding of the exsolved materials superior catalytic properties, the project also aimed to quantitatively analyse the chemical, structural, and microstructural features governing their catalytic mechanisms using a set of in situ/operando cutting-edge characterisation techniques. The ultimate goal was to create a combined method for identifying the principles that would determine an enhancement of the catalytic activity of the developed materials. This set of principles would then enable the rational design of an optimised catalyst, informed by this assessment.
