PREDICTION OF CO2 REDUCTION REACTION (CO2RR) BY TRANSITION METALS ON SINGLE VACANCY GRAPHENE STRUCTURES

• Main Author: Majeed Himat, Abdul
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/81442
• Institution: Institut Teknologi Bandung

States (DOS) and Partial density of states (PDOS) analyses reveal that the d orbitals of Ti, Co, Cu, and Ni significantly contribute to peaks near the Fermi level, dominated by the p orbital of the carbon atoms. The d orbitals of Pt symmetrically contribute to peaks in the conduction band, whereas Zn and Sn’s d orbitals do not. Charge density difference analysis shows negative charge accumulation around all TMs, indicating charge transfer from carbon atoms. This finding confirms that Ti, Ni, Cu, Zn, and Sn have insufficient charge redistribution to induce significant CO2 bending, resulting in weak interactions with CO2. Conversely, Co and Pt on SV graphene demonstrate effective CO2 activation, positioning these configurations as promising candidates for next-generation catalysts in the electrochemical CO2RR. Furthermore, the reduction of CO2 to CO and HCOOH through a two-electron/proton transfer pathway was considered. On Co and Pt catalytic surfaces, we were able to obtain CO and a molecule of water by reducing CO2. The final products (CO + H2O) on the Co catalytic surface are obtained with a reaction energy of -0.443 eV. When reducing CO2 to HCOOH, the reaction requires energies of 0.8525 eV and 0.0828 eV through pathway mechanisms A and B, respectively. On the other hand, for the Pt catalytic surface, the reaction energy for (CO + H2O) was -0.422 eV, and for HCOOH, the reaction energies are 0.1065 eV and 0.7533 eV through pathway mechanism A and B respectively. Pathway A reduces CO2 to HCOOH through a carboxylate intermediate, while Pathway B does so through a formate intermediate. Looking into the high energy activation barrier through formate pathway, makes the reaction kinetically unfavorable. In a conclusion, both CO and formic acid reactions will proceed favorably via the carboxylate intermediate, but not the formate pathway.