Research Projects

The rise in atmospheric CO₂ from excessive fossil fuel burning accelerates climate change and global warming. This issue can be addressed by capturing CO₂ and converting it into value-added chemicals like CH₃OH, CH₄, and CO. However, CO₂ hydrogenation is challenging due to its inertness and stability. Effective catalysts are essential, and recent studies suggest the various types of homogeneous and heterogeneous catalysts used in this process and here transition metal dimer may offer a promising solution for efficient CO₂ reduction. CO₂ capture is essential for catalysts to function effectively during the hydrogenation process. Previous studies have demonstrated successful CO₂ capture using two-dimensional transition metal borides and carbides. K. H. Bowen et al. achieved promising results in CO₂ activation and hydrogenation using palladium and platinum hydrides (PdH⁻ and PtHₙ⁻). Transition and post-transition metals have thus emerged as effective catalysts for CO₂ hydrogenation. The transition metal surfaces provide strong interactions with reactants due to functionalized d-band centers, optimal adsorption geometries, and favourable local environments which enhancing CO₂ electroreduction activity and selectivity. In contrast, using cationic and anionic transition complexes in some studies often require counterions for stability, which can reduce catalytic activity. Neutral molecules bypass this limitation and serve as better catalysts. Additionally, bimetallic catalysts have also shown improved performance and there surface-supported bimetallic nanoparticles, such as PdAg, effectively activate CO₂ by inserting hydrogen atoms. Transition metal group VI dimers such as Cr₂, Mo₂, and W₂ have drawn considerable theoretical and experimental attention due to their ability to form sextuple bonds through nd and (n+1)s orbitals. These bonds create high electron density and strong d-band centers, making the dimers promising for catalytic applications by facilitating bond activation via electron sharing. Dual-atom site catalysts (DACs) have emerged as a new class of materials with enhanced catalytic performance due to synergistic interactions between adjacent metal atoms. For example, Y. Li demonstrated that a Pd₂-based DAC can efficiently catalyse electrochemical CO₂ reduction. Motivated by such work, I aim to explore CO₂ hydrogenation using homopolar or heteropolar transition metal dimers. Zhang et al. recently showed that Cu dimers and trimers embedded in graphene outperform single-atom catalysts (SACs) in CO₂-to-methane conversion due to lower thermodynamic barriers and better selectivity. Dimers may offer superior electron density and activity where SACs fall short. This project aims to investigate transition metal dimers supported on carbon dots or 2D nanosheets for CO₂ reduction. Theoretical studies will help experimentalists in designing efficient catalysts to convert CO₂ into valuable products and support sustainable energy solutions