Au@NiS<sub>x</sub> Yolk@Shell Nanostructures as Dual‐Functional Electrocatalysts for Concomitant Production of Value‐Added Tartronic Acid and Hydrogen Fuel
Truong‐Giang Vo, Giang‐Son Tran, Chao‐Lung Chiang, Yan‐Gu Lin, Huai‐En Chang, Hsuan‐Hung Kuo, Chia‐Ying Chiang, Yung‐Jung Hsu
Abstract
Abstract Efficient glycerol electrooxidation reaction (GEOR) over gold@nickel sulfide (Au@NiS x ) yolk@shell nanostructures is demonstrated, achieving ≈50.4% glycerol conversion at 10 h, 92.6% selectivity toward three‐carbon products, and 90.7% total Faradaic efficiency. By regulating the electrode potential, tartronic acid (TART), one of the highest value‐added intermediates, can be produced with a selectivity as high as 43.1% and a yield of 45.6 µmol cm −2 h −1 . A combination of ex situ microstructural analysis, operando Raman, and operando X‐ray absorption measurements reveals a dynamic surface reconstruction course from Au@NiS x to Au@NiS x /NiOOH during the glycerol oxidation process. The unique reconstructed architectures featuring conductive interior NiS x components and active surface high‐valence Ni 3+ species account for the superior GEOR performance. Further integration of GEOR with hydrogen evolution reaction is realized by employing Au@NiS x as both anode and cathode electrocatalysts in a two‐electrode configuration. Concomitantly production of TART and hydrogen fuel is accomplished. This study demonstrates that Au@NiS x not only can convert glycerol to TART with remarkable efficiency and selectivity, but also can produce hydrogen at a moderate level. The findings from this study can facilitate the development of dual‐functional electrocatalysts capable of producing high‐value products at both the cathode and anode sides.