CO2 hydrogenation to methanol over Cu catalysts supported on La-modified SBA-15: the crucial role of Cu–LaOx interfaces

DOI: 10.1016/j.apcatb.2019.03.059

Authors: Kun Chen (Xiamen University) , Huihuang Fang (Xiamen University) , Simson Wu (University of Oxford) , Xi Liu (Synfuels China Co. Ltd) , Jianwei Zheng (University of Oxford) , Song Zhou (Institute of Coal Chemistry, Chinese Academy of Sciences) , Xinping Duan (Xiamen University) , Yichao Zhuang (Xiamen University) , Shik Chi Edman Tsang (University of Oxford) , Youzhu Yuan (Xiamen University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Applied Catalysis B: Environmental

State: Published (Approved)
Published: March 2019

Abstract: The direct hydrogenation of CO2 to methanol has become a very active research field because CO2 can be prospectively recycled to mitigate greenhouse effect and store clean synthetic fuels. This reaction can be catalyzed by supported Cu catalysts and the catalysts display strong support or promoter effects. Sintering of Cu species accelerates the separation of Cu–oxide interfaces, reduces the active component, and diminishes the methanol selectivity. In this work, we report a Cu catalyst supported on La-modified SBA-15, where the Cu–LaOx interface is generated through the interaction of highly dispersed Cu nanoparticles with LaOx species bedded into the SBA-15 pore wall. The optimized Cu1La0.2/SBA-15 catalyst can achieve methanol selectivity up to 81.2% with no deterioration in activity over 100 h on stream compared with the La-free catalyst. A thorough study reveals that La species not only significantly improve the CO2 adsorption but also enhance Cu dispersion to produce well-dispersed active sites. The H/D exchange experiments show that the methanol synthesis displays a strong thermodynamic isotope effect and the Cu–LaOx interface plays a crucial role for the methanol synthesis rate in CO2/D2 feed. In situ DRIFTS studies reveal that *HCOO and *OCH3 species are the key intermediates formed during the activation of CO2 and methanol synthesis over the Cu1La0.2/SBA-15 catalyst.

Journal Keywords: CO2 hydrogenation; methanol synthesis; La-modified SBA-15; supported Cu catalyst; Cu–LaOxinterface

Subject Areas: Chemistry, Environment


Instruments: B18-Core EXAFS

Added On: 27/03/2019 09:02

Discipline Tags:

Earth Sciences & Environment Climate Change Physical Chemistry Catalysis Chemistry

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) Extended X-ray Absorption Fine Structure (EXAFS)