Electrification Pathways for CO2 Valorization: Electrocatalytic and Plasma-Based Approaches

This thesis explores innovative CO₂ conversion and catalysis approaches, focusing on sustainable technologies that transform CO₂ from a waste product into valuable chemicals. Through a multidisciplinary framework, the work integrates biomass-derived materials, nanostructured catalysts, and plasma-catalysis synergies to develop efficient solutions for reducing greenhouse gas emissions. Chapter 1 introduces CO₂ as a central challenge in climate change and examines its potential for valorising through Carbon Capture and Utilization (CCU) strategies. By leveraging processes such as plasma catalysis and electrocatalysis, CO₂ can be transformed into value-added products, offering the dual benefit of mitigating emissions and creating useful chemicals. Chapter 2 focuses on the utilization of biomass-derived materials for CO₂ conversion. Specifically, carbon materials obtained from citrus peel biomass are employed to create effective electrocatalysts for CO₂ reduction. These biomassbased catalysts, enriched with heteroatoms, exhibit high surface area and enhanced electron transfer, contributing to more efficient and selective catalytic processes. In Chapter 3, the synthesis of nanostructured catalysts is explored using techniques such as dip-coating and anodic oxidation. Titanium dioxide nanotubes (TiNTs) are developed on carbon-coated supports to optimize catalytic performance. These nanotube structures would play a crucial role in electrocatalysis, particularly in reactions like the selective hydrogenation of oxalic acid. Additionally, their potential for integration into plasma-catalysis systems is highlighted, where the synergy between plasma and nanostructured surfaces would further enhance CO₂ conversion efficiency. ii Chapter 4 delves into the application of plasma-catalysis for CO₂ conversion, demonstrating how plasma can activate molecules under mild conditions to accelerate chemical reactions. In this work, an innovative Dielectric Barrier Discharge (DBD) surface-confined reactor is utilized, which enhances the interaction between plasma and catalytic surfaces. By incorporating nanostructured catalysts such as Titanium nanotubes obtained on Ti gauze and nanotubes functionalized with gold and silver particles, into this reactor, the synergy between plasma and the catalyst is optimized, significantly improving the efficiency and scalability of CO₂ conversion processes. This setup allows for more controlled and efficient chemical transformations, making it a promising approach for large-scale industrial applications.The thesis presents a comprehensive approach to addressing CO₂ emissions through advanced catalytic technologies. By combining renewable biomass, nanotechnology, and plasma systems, it contributes to the development of sustainable methods for CO₂ valorization, paving the way for greener and more efficient chemical processes.