The promotional effect of gallium loading on the bifunctional Cu–Ga/γ-Al2O3catalyst for CO2hydrogenation to methanol and dimethyl ether at atmospheric pressure

Date

2026-01-01

Author

Osmanağa, Sezer
Kaya, Yasemin
Önal, Işık
İpek Torun, Bahar

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

41
views

0
downloads

Cite This

Hydrogenation of CO2 to methanol and dimethyl ether (DME) was investigated over gallium-promoted copper catalysts supported on γ-Al2O3 (Cu–Ga/γ-Al2O3) at atmospheric pressure—conditions under which Ga-promoted Cu/γ-Al2O3 catalysts have not been investigated before. Reaction parameters—including temperature, H2 : CO2 feed ratio, and gas hourly space velocity (GHSV)—were optimized prior to evaluating the effect of Ga loading. Catalysts with varying Ga loadings (5, 10, 12, and 15 wt%) were tested, with the 5 wt% Ga catalyst achieving the highest combined formation rate of methanol and DME at 246 μmolcarbon gcat−1 h−1 and a combined selectivity of 20.6% under optimal conditions (220 °C, 9 : 1 H2 : CO2, GHSV = 30 000 mL gcat−1 h−1), where the DME production rate was twofold that of the Ga-free catalyst. For comparison, a commercial Cu/ZnO/Al2O3 catalyst was synthesized and showed a significantly lower methanol selectivity (7.2%) and formation rate (60 μmol gcat−1 h−1) under identical operating conditions, with no DME production observed. The promotional effect of Ga was further explored using periodic density functional theory (DFT) calculations on a Cu4/β-Ga2O3(001) model. Theoretical results suggest that CO2 hydrogenation proceeds primarily via a carboxyl intermediate, rather than through formate or CO pathways.

URI

https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=105028123763&origin=inward
https://hdl.handle.net/11511/118599

Collections

Department of Chemical Engineering, Article