Operando high-pressure investigation of size-controlled CuZn catalysts for the methanol synthesis reaction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33664267.
- Also identified by DOI 10.1038/s41467-021-21604-7 and PMC identifier 7933282.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Although Cu/ZnO-based catalysts have been long used for the hydrogenation of CO<sub>2</sub> to methanol, open questions still remain regarding the role and the dynamic nature of the active sites formed at the metal-oxide interface. Here, we apply high-pressure operando spectroscopy methods to well-defined Cu and Cu<sub>0.7</sub>Zn<sub>0.3</sub> nanoparticles supported on ZnO/Al<sub>2</sub>O<sub>3</sub>, γ-Al<sub>2</sub>O<sub>3</sub> and SiO<sub>2</sub> to correlate their structure, composition and catalytic performance. We obtain similar activity and methanol selectivity for Cu/ZnO/Al<sub>2</sub>O<sub>3</sub> and CuZn/SiO<sub>2</sub>, but the methanol yield decreases with time on stream for the latter sample. Operando X-ray absorption spectroscopy data reveal the formation of reduced Zn species coexisting with ZnO on CuZn/SiO<sub>2</sub>. Near-ambient pressure X-ray photoelectron spectroscopy shows Zn surface segregation and the formation of a ZnO-rich shell on CuZn/SiO<sub>2</sub>. In this work we demonstrate the beneficial effect of Zn, even in diluted form, and highlight the influence of the oxide support and the Cu-Zn interface in the reactivity.