Unraveling surface sensitivity for generating metastable active sites in molybdenum-based catalysts for CO<sub>2</sub> hydrogenation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41285926.
- Also identified by DOI 10.1038/s41467-025-66430-3 and PMC identifier 12722216.
- 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
The reverse water-gas shift (RWGS) reaction is crucial for sustainable CO<sub>2</sub> conversion, yet catalyst surface remodeling at high temperatures remains a complex and pivotal phenomenon. This study investigates the complex relationship between surface reconstruction and catalytic performance using a series of molybdenum-based catalysts, which can generate different catalytic MoO<sub>3</sub> surface layers under RWGS conditions. In-situ characterization techniques and theoretical analyses reveal that the MoO<sub>3</sub> layer on MoO<sub>3</sub>/MoO<sub>2</sub>-C and MoO<sub>3</sub>/Mo<sub>2</sub>N-C is in-situ reduced to MoO<sub>2</sub> and metastable MoO<sub>x</sub> (2 <x < 3), respectively, while it is not reduced on MoO<sub>3</sub>/Mo<sub>2</sub>C-C during the catalysis process. The metastable MoO<sub>x</sub> species on MoO<sub>3</sub>/Mo<sub>2</sub>N-C shows an unprecedented CO yield (up to 48.3 %) nearing the equilibrium conversion limit, a CO formation rate of 8.26 × 10<sup>-5</sup> mol<sub>CO</sub> g<sub>cat</sub><sup>‒1</sup> s<sup>‒1</sup>, and 99 % CO selectivity under 500 °C. The function and formation conditions of metastable MoO<sub>x</sub> sites are comprehensively investigated in this work.