Alkyne Semihydrogenation over Pd Nanoparticles Embedded in N,S-Doped Carbon Nanosheets

Abstract

A strategy using biological materials to prepare N,S-doped carbon covering Pd nanoparticles (Pd/N,S-C) from natural silk fibroin was developed. Wet chemical reduction and carbonization were used to synthesize the Pd/N,S-C catalyst. The asprepared catalyst showed high activity (>99%) with satisfactory selectivity (86−99%) for semihydrogenation of varied alkynes to corresponding alkenes. In addition, this work also demonstrated that the PdC x species disappeared and the effect of electron transfer between Pd and N,S-C enhanced when Pd/N,S-F (N,S-doped silk fibroin covering Pd nanocrystals) was calcined to form Pd/N,S-C, which was beneficial to improve its performance for hydrogenation. Meanwhile, the increase of specific surface area after carbonization and the embedded structure could also improve the catalytic activity of Pd/N,S-C and stereoselectivity to cis-alkenes.

N, S, P-Tridoped Coal-Derived Hierarchically Porous Carbon Aerogel for High-Performance Supercapacitors

“…The XPS survey spectra proved the presence of C, N, O, P, and S elements in DCAs, N-DCAs, N-P-DCAs, N-S-DCAs, and N-P-S-DCAs in Figure S3. As shown in Figure b, the N 1s spectra of N-P-S-DCAs show four characteristic peaks centered at approximately 397.38, 398.08, 399.38, and 400.48 eV, which are assigned to pyridinic N (N-6), pyrrolic N (N-5), graphitic N (N-Q), and oxidized N, respectively Figure c shows the high-resolution C 1s XPS spectra, which exhibit two main peaks at 283.98 eV (CC) and 284.58 eV (C–C).…”

Enhancing Photocatalytic‐Transfer Semi‐Hydrogenation of Alkynes Over Pd/C3N4 Through Dual Regulation of Nitrogen Defects and the Mott–Schottky Effect

“…Notably, the olefin products obtained by Pd/DCN were significantly higher than those obtained by Pd/BCN under both light and dark conditions, mainly because the DCN carrier exhibited better regulation of Pd. Therefore, the role of the Mott–Schottky effect was to enhance selectivity, [ 18,25,68,69 ] and these enhancements were not affected by visible light. BCN and DCN showed almost no catalytic activity in the absence of Pd, indicating that Pd was the active center for the transfer hydrogenation (Figure S22, Supporting Information).…”

“…[17] However, their toxicity often limits their application; thus, sustainable and efficient catalysts require further development. [18] To date, significant efforts have been made to modify Pd catalysts, such as the preparation of single atoms, [19,20] construction of alloy or core-shell structures (PdCu, PdIn, PdAg, Pd@PPy-600), [21][22][23][24] and utilization of Mott-Schottky interactions between metals and carriers. [25] However, these selectivity enhancement methods often result in decreased activity.…”

Highly Selective Semihydrogenation via a Wettability-Regulated Mass Transfer Process

“…The small differences in the TOFs of these samples could be ascribed to their distinct dispersities in water. In addition, the unremarkable TOF values attained over gel-supported catalysts are mainly because all the reactions were conducted in a water solvent. − …”