Presentation Information
[3H09]Adsorption behavior of formaldehyde on Zn/Cu(111) model catalyst
*Ayumu Sakurai1, Tetta Takeuchi2, Junji Nakamura3, Takahiro Kondo4, Kotaro Takeyasu5 (1. Graduate School of Science and Technology, University of Tsukuba, 2. Graduate School of Environmental Science, Hokkaido University, 3. International Institute for Carbon-Neutral Energy Research, Kyushu University, 4. Institute of Pure and Applied Sciences, University of Tsukuba, 5. Institute for Catalysis, Hokkaido University)
Methanol is synthesized via CO2 hydrogenation using Cu/ZnO/Al2O3 catalysts, though the role of Zn remains unclear. We previously showed that formaldehyde, a key intermediate, can be produced from formate on a Zn/Cu(111) model catalyst. Here, we investigated how Zn affects formaldehyde adsorption behavior and energy stabilization. Zn(0.2 ML)/Cu(111) was prepared by Zn deposition on Cu(111), followed by formaldehyde exposure at 170 K. Adsorbed species were analyzed by IRAS and TPD. TPD revealed a desorption peak at ~200 K on Cu(111), and an additional peak at ~208 K on Zn/Cu(111), attributed to formaldehyde on Zn sites. The small desorption energy difference (~2 kJ/mol) suggests that Zn only weakly stabilizes formaldehyde. These results indicate that Zn's main contribution likely lies in earlier steps, such as formate formation and hydrogenation, rather than in formaldehyde adsorption.