Enhanced CO2-to-CH4 conversion via grain boundary oxidation effect in CuAg systems
• Ag enrichment at grain boundaries induces significant oxidation effects. • Enhanced performance stems from stabilized Cu δ+ species and unique electron transfer. • The CO 2 -to-CH 4 pathway and the sluggish quenching of intermediates are revealed. • Grain boundary oxidation effect on CH 4 conversion is twice that of conventional effects. The authentic active sites of oxide-derived copper (OD-Cu), namely grain boundaries (GBs) and oxidized Cu δ+ species, is still debatable, and their role in governing CH 4 conversion remains unclear. Herein, this study answers these questions using bimetallic catalysts by novel electro-shock strategy with controllable GBs for the oxidization of Cu δ+ species by modulating Ag loading. The Ag enrichment at the GBs facilitates the bonding of oxygen with the uncoordinated Cu atoms, resulting in GB oxidation effect. The obtained CH 4 selectivity is twice that of GBs or nanoalloy effect. The enhanced performance is attributed to the stable Cu δ+ species and unique electron transfer mechanism from GB oxidation structure. Operando attenuated-total-reflection Fourier-transform-infrared-spectroscopy unveils the reaction pathway of CO 2 -to-CH 4 and the sluggish reversible quenching processes of intermediates. Theoretical calculations indicate that the weak *CO adsorption on GB oxidation structure facilitates *CO hydrogenation, promoting CO 2 -to-CH 4 conversion.
Authors
- Samira Siahrostami (ORCID: https://orcid.org/0000-0002-1192-4634)
- Yimin A. Wu (ORCID: https://orcid.org/0000-0002-3807-8431)
- Ning Chen (ORCID: https://orcid.org/0000-0002-1269-6119)
- Joel P. Mills
- Jamie H. Warner (ORCID: https://orcid.org/0000-0002-1271-2019)
- Dmitry Akhmetzyanov (ORCID: https://orcid.org/0009-0003-4632-0288)
- Zhongchao Tan (ORCID: https://orcid.org/0000-0001-7922-8291)
- Lei Wang (ORCID: https://orcid.org/0000-0001-7275-4846)
- Yi Feng Xiao (ORCID: https://orcid.org/0000-0001-6318-8010)
- Brant Billinghurst (ORCID: https://orcid.org/0000-0002-5346-5317)
- Khaled M. Ibrahim (ORCID: https://orcid.org/0000-0001-9000-6147)
- Chandra Veer Singh (ORCID: https://orcid.org/0000-0002-6644-0178)
- Cheng Du (ORCID: https://orcid.org/0000-0001-6068-4895)
- Youchao Teng (ORCID: https://orcid.org/0000-0003-3579-4579)
- Xue Yao (ORCID: https://orcid.org/0000-0002-7136-2231)
- Weifeng Chen (ORCID: https://orcid.org/0000-0002-6667-2403)
- Xiyang Wang (ORCID: https://orcid.org/0000-0002-7591-6676)
- Yongzan Zhou (ORCID: https://orcid.org/0000-0002-9499-5306)
- Tao Guo (ORCID: https://orcid.org/0000-0002-9909-6705)
- Zuolong Chen
Institutions
- University of Waterloo (CA)
- Simon Fraser University (CA)
- University of Toronto (CA)
- Université Bourgogne Franche-Comté (FR)
- Zhejiang Business Technology Institute (CN)
- Canadian Light Source (Canada) (CA)
- The University of Texas at Austin (US)
Publication Details
- Journal
- Chemical Engineering Journal
- Published
- 2024-10-16
- DOI
- https://doi.org/10.1016/j.cej.2024.156728
- Citations
- 4
- Primary Topic
- CO2 Reduction Techniques and Catalysts
- Type
- article
- Field-Weighted Citation Impact
- 0.41
Funders
- Natural Sciences and Engineering Research Council of Canada