Electroreductive coupling of benzaldehyde by balancing the formation and dimerization of the ketyl intermediate.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36564379.
- Also identified by DOI 10.1038/s41467-022-35463-3 and PMC identifier 9789095.
- 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
Electroreductive coupling of biomass-derived benzaldehyde offers a sustainable approach to producing value-added hydrobenzoin. The low efficiency of the reaction mainly ascribes to the mismatch of initial formation and subsequent dimerization of ketyl intermediates (Ph-CH = O → Ph-C·-OH → Ph-C(OH)-C(OH)-Ph). This paper describes a strategy to balance the active sites for the generation and dimerization of ketyl intermediates by constructing bimetallic Pd/Cu electrocatalysts with tunable surface coverage of Pd. A Faradaic efficiency of 63.2% and a hydrobenzoin production rate of up to 1.27 mmol mg<sup>-1</sup> h<sup>-1</sup> (0.43 mmol cm<sup>-2</sup> h<sup>-1</sup>) are achieved at -0.40 V vs. reversible hydrogen electrode. Experimental results and theoretical calculations reveal that Pd promotes the generation of the ketyl intermediate, and Cu enhances their dimerization. Moreover, the balance between these two sites facilitates the coupling of benzaldehyde towards hydrobenzoin. This work offers a rational strategy to design efficient electrocatalysts for complex reactions through the optimization of specified active sites for different reaction steps.