Au@NiS_x Yolk@Shell Nanostructures as Dual‐Functional Electrocatalysts for Concomitant Production of Value‐Added Tartronic Acid and Hydrogen Fuel

Abstract

Efficient glycerol electrooxidation reaction (GEOR) over gold@nickel sulfide (Au@NiSx) 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@NiSx to Au@NiSx/NiOOH during the glycerol oxidation process. The unique reconstructed architectures featuring conductive interior NiSx components and active surface high‐valence Ni3+ species account for the superior GEOR performance. Further integration of GEOR with hydrogen evolution reaction is realized by employing Au@NiSx 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@NiSx 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.

Nanoparticulate WN/Ni3C Coupling in Ceramic Coatings for Boosted Urea Electro‐Oxidation

“…As shown in Figure 4a, high-resolution Ni 2p spectra of both WN/Ni 3 C and Ni 3 C can be deconvoluted into two remarkable peaks corresponding to Ni 2p 1/2 and Ni 2p 3/2 , showing the existence of two different valance states of Ni (i.e., Ni 0 and Ni 2+ ). The higher content of Ni 2+ peak displays a dominant valance state of Ni(II) in WN/Ni 3 C and Ni 3 C. [16] Typically, the peaks located at 855.39 and 872.99 eV are assigned to Ni 2+ of Ni 2p 3/2 and Ni 2p 1/2 in WN/Ni 3 C. [16,17] And the binding energy shows positive shifts of 0.2 and 0.6 eV, compared with those of Ni 3 C, respectively. The high-resolution spectra of W 4f in WN/Ni 3 C and WN can be deconvoluted into two remarkable peaks of W 4f 5/2 and W 4f 7/2 , which are attributed to W─N and W─O bonds (Figure 4b).…”

Enabling direct-growth route for highly efficient ethanol upgrading to long-chain alcohols in aqueous phase

“…The deconvoluted peaks of S 2p spectra can be assigned to Ni-S (162.3 and 163.7 eV) 29 , C-S species (164.1 and 165.1 eV) 30 and oxidation of surface sulfur species (168.8 eV) 31 . In addition, the Ni 2p 3/2 spectra show that the dominant peaks at 853.0 eV can be assigned to metallic Ni 0 , whereas the small peaks at 854.2 and 856.5 eV correspond to NiO and other Ni 2+ species (NiS x , Ni(OH) 2 or NiCO 3 ), respectively 25,[32][33][34][35][36] . It is noteworthy that the Ni/S ratios determined from XPS are substantially lower than those from ICP-OES and elemental analysis (Supplementary Table 1), implying that the sulfur species are mainly distributed on the catalyst surface.…”

Manipulation of interfacial charge dynamics for metal–organic frameworks toward advanced photocatalytic applications

“…While the in situ time-resolved PL and TA studies can offer invaluable insights, the challenges associated with experimental complexity, sample preparation, and data analysis need to be addressed. Other real-time analytical techniques, such as in situ X-ray photoelectron spectroscopy 134,135 and operando Raman spectroscopy, 136,137 can provide complementary information to the establishment of a veritable working mechanism.…”