Highly Efficient Electrocatalytic Upgrade of <i>n</i>‐Valeraldehyde to Octane over Au SACs–NiMn<sub>2</sub>O<sub>4</sub> Spinel Synergetic Composites
Meichun Qin, Shiying Fan, Xinyong Li, Zhaodong Niu, Chunpeng Bai, Guohua Chen
Abstract
Abstract In this work, electrocatalytic upgrade of n ‐valeraldehyde to octane with higher activity and selectivity is achieved over Au single‐atom catalysts (SACs)–NiMn 2 O 4 spinel synergetic composites. Experiments combined with density functional theory calculation collaboratively demonstrate that Au single‐atoms occupy surface Ni 2+ vacancies of NiMn 2 O 4 , which play a dominant role in n ‐valeraldehyde selective oxidation. A detailed investigation reveals that the initial n ‐valeraldehyde molecule preferentially adsorbs on the Mn tetrahedral site of NiMn 2 O 4 spinel synergetic structures, and the subsequent n ‐valeraldehyde molecule easily adsorbs on the Ni site. Specifically, Au single‐atom surficial derivation over spinel lowers the adsorption energy ( E ads ) of the initial n ‐valeraldehyde molecule, which will facilitate its adsorption on the Mn site of Au SACs–NiMn 2 O 4 . Furthermore, the single‐atom Au surficial derivation not only alters the electronic structure of Au SACs–NiMn 2 O 4 but also lower the E ads of subsequent n ‐valeraldehyde molecule. Hence, the subsequent n ‐valeraldehyde molecules prefer adsorption on Au sites rather than Ni sites, and the process of two alkyl radicals originating from Mn–C 4 H 9 and Au–C 4 H 9 dimerization into an octane is accordingly accelerated. This work will provide an avenue for the rational design of SACs and supply a vital mechanism for understanding the electrocatalytic upgrade of n ‐valeraldehyde to octane.