THEORETICAL STUDY OF HYDROGENATION OF CARBON DIOXIDE USING GRAPHENE-SUPPORTED NICKEL CLUSTER CATALYST

• Main Author: Rizky Pradana, Mochamad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/46874
• Institution: Institut Teknologi Bandung

Carbon dioxide (CO2) conversion through hydrogenation reaction is one of methods to reduce greenhouse gas emission in the atmosphere while producing compounds that have high economic value such as formic acid (HCOOH) and carbon monoxide (CO). One of the challenges for hydrogenation reaction of CO2 is to find a catalyst that adsorbs CO2 and splits H2 molecule into hydrogen atom efficiently because the two molecules are raw materials for CO2 hydrogenation. Moreover, one of parameters for efficient catalyst is to be able to reduce activation energy for each of elementary reactions. Graphene-supported nickel cluster catalyst is proposed to be alternative for CO2 hydrogenation catalyst. This thesis will simulate CO2 hydrogenation to CO and HCOOH. CO is the main ingredient for Fischer-Tropch reaction, while HCOOH can be used for fuels and hydrogen storage medium. CO creation through reverse water gas shift (RWGS) pathway reaction consists of carboxyl (COOH) creation and dissociation of CO and water. Meanwhile, HCOOH creation is consisted of the creation of formate (HCOO) and HCOOH itself. It is found that, the strongest CO2 adsorption is on Ni7 cluster with adsorption energy of -1.15 eV in cluster adsorption site. In the formate reaction pathway, the activation energy of HCOO elementary reaction is 0.94 eV. Next, the HCOOH formation’s activation energy is 2.21 eV. In the RWGS reaction pathway, the activation energy of COOH elementary reaction is 0.98 eV. Furthermore, the formation of CO and water needs the activation energy value of 0.015 eV. Based on the activation energy value, hydrogenation of CO2 with graphene-supported nickel cluster catalyst will prefer to go to RWGS pathway. Therefore, graphene-supported nickel cluster catalyst can be used as an altenative of catalyst for CO2 hydrogenation to CO.