CO2 HYDROGENATION TO FORMIC ACID ON CU(100) AND ZN/CU(100)

• 主要作者: Akbar Mubarok, Fikri
• 格式: Theses
• 語言: Indonesia
• 在線閱讀: https://digilib.itb.ac.id/gdl/view/71792
• 機構: Institut Teknologi Bandung

Transformation of CO2 gas into methanol is one of promissing strategy to reduce its emissions in the atmosphere. In industrial scale, methanol is synthesized on Cu based catalyst from CO2 hydrogenation. The synthesis process consists of several intermediate steps, one of them is formic acid formation. The mechanism of formic acid synthesis on clean and Zn-modified Cu catalyst was studied by employing density functional theory (DFT) calculations. The van der Waals correction was included to prevent the weak interaction between CO2 and copper surfaces. Our study showed that the binding energy of CO2 on Cu(100) is well defined by using optB86b-vdW functional rather than PBE. The CO2 is physisorbed on Cu(100) with an adsorption energy of -0.22 eV. The activation energy of CO2 hydrogenation to formate on clean Cu(100) is 0.32 eV. Compared to clean Cu(100), the Zn cluster on Cu(100) could reduce the activation energy of formate synthesis by only 0.04 eV. Meanwhile, there were no significant contributions from a single Zn dopant and a single Zn adatom. Furthermore, the activation energy of formic acid synthesis through formate hydrogenation was known very high due to the strong binding energy of formate on the surfaces. The activation energy of formic acid synthesis on Zn-modified Cu(100) was not different from that of clean Cu(100).