DESIGN OF PALADIUM CLUSTER-BASED CATALYST FOR CARBON DIOXIDE HYDROGENATION WITH DENSITY FUNCTIONAL THEORY

• Main Author: Unggul Karami, Muhammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/44843
• Institution: Institut Teknologi Bandung

Carbon dioxide (CO2) conversion to methanol through hydrogenation is one of solutions to decrease CO2 level in the atmosphere and obtaining renewable energy source. However, with the application of conventional catalyst (e.g. Cu- Based Catalyst), methanol yield is relatively low. Moreover, temperature and pressure needed to operate is high so the operational cost is expensive. Therefore, there is an interest to develop new catalyst which can operate in lower pressure and temperature. In this final project, paladium cluster-based catalyst is offered to become the new catalyst for CO2 hydrogenation which has potential to operate in relatively low pressure and temperature. In this project, CO2adsorption and formation of HOCO and HCOO will be modeled by means of density functional theory. This two processes are the beginning stage of CO2 hydrogenation to methanol. From the result of simulation, CO2 adsorption occured at PdN clusters (N=7,9,13). The strongest CO2 adsorption occured at Pd7 cluster with adsorption energy value of -0.3 eV(-0.3 eV with ZPE contribution). CO2 adsorption will tend to be weaker with the increasing of cluster size. With the usage of paladium cluster catalyst, HCOO formation more likely to happen than HOCO energetically. Elementary reaction of CO2 + H to HOCO has activation energy of 1.63 eV(1.58 with ZPE) and the reaction energy of 0.41 eV(0.58 eV with ZPE). On the other hand, elementary reaction of CO2 + H to HCOO has activation energy of 0.87 eV(0.99 with ZPE) and the reaction energy of -0.1 eV(0.06 eV with ZPE). The application of paladium cluster as catalyst reduce the activation energy of elementary reaction of CO2 + H to HCOO compared to Cu-based catalyst. Hence, paladium cluster has potentials to be catalyst for CO2 hydrogenation with low temperature and pressure in order to reduce the operational cost of CO2 hydrogenation.