Triggering photocatalytic performance of La<sub>2</sub>Co<sub>x</sub>Mn<sub>2-x</sub>O<sub>6</sub> via heat activation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37871212.
- Also identified by DOI 10.1073/pnas.2310004120 and PMC identifier 10622888.
- Licence recorded as CC BY-NC-ND.
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Abstract
The La-based perovskite (LaBO<sub>3</sub>) exhibits excellent optical properties. However, its valence band (VB) potential is not sufficiently positive to reach the oxidation potential required for the cleavage of chemical bonds (such as benzylic C-H), limiting its application in photocatalysis. Herein, we report the unconventional effects of heat activation on the reduction of the dissociation energy of benzylic C-H and aqueous H-O, thereby triggering the photocatalytic activity of La<sub>2</sub>Co<sub>x</sub>Mn<sub>2-x</sub>O<sub>6</sub> perovskites. Additionally, we demonstrate that photocatalysis is the main contributor to substrate conversion in the selective oxidation of toluene and reduction of CO<sub>2</sub>. Particularly, La<sub>2</sub>Co<sub>1.5</sub>Mn<sub>0.5</sub>O<sub>6</sub> shows excellent performance with a product yield of 550.00 mmol g<sub>cat</sub><sup>-1</sup> and a toluene conversion of 22,866.67 μmol g<sub>cat</sub><sup>-1</sup> h<sup>-1</sup>. To the best of our knowledge, this is the highest reported product yield for the selective oxidation of benzylic C-H bond of toluene. Our findings provide insight into the specific role of heat activation in photocatalysis, which is crucial for breaking and overcoming the VB barrier to realize challenging reactions.