Unraveling a Biomass-Derived Multiphase Catalyst for the Dehydrogenative Coupling of Silanes with Alcohols under Aerobic Conditions

Abstract

Herein, a novel silver and chromium nanostructured N-doped carbonaceous material has been synthesized by a biomass-annealing approach using readily available chitosan as a raw material. The resulting catalyst AgCr@CN-800 has been applied for the dehydrogenative coupling reaction of various silanes with different alcohols to obtain the corresponding silyl ethers under aerobic and mild conditions. Besides excellent activity and selectivity, the as-prepared catalyst exhibits good stability and reusability. Characterization by XRD, XPS, ICP-MS, HRTEM, in combination with careful examination of the structure with Cs-corrected HAADF-STEM revealed that catalyst AgCr@CN-800 comprises Ag and CrN aggregated particles, as well as highly dispersed Ag-Nx and Cr-Nx sites embedded in N-doped graphitic structures. A comparative catalytic study using structure-related catalysts in combination with acid-leaching treatments has shown that the most active species are the Ag particles, and that their activity is boosted by the presence of Cr-derived species. By in-situ Raman spectroscopy experiments, it has been found that the dehydrogenative coupling of silanes with alcohols in the presence of catalyst AgCr@CN-800 takes place through an oxygen-assisted mechanism.

Introducing Structural Diversity: Fe2(MoO4)3 Immobilized in Chitosan Films as an Efficient Catalyst for the Selective Oxidation of Sulfides to Sulfones

“…Very recently, we presented a chitosan/α‐Ag 2 WO 4 composite generated by femtosecond laser irradiation as a highly efficient material to kill bacteria and inactivate SARS‐CoV‐2 by contact, showing the existing synergistic effect between chitosan and α‐Ag 2 WO 4 [19] . We also developed new catalysts for the dehydrogenative coupling of silanes with alcohols through the immobilization of Ag and Cr nanoparticles on the surface of an N‐doped carbon support derived from the burning of chitosan [20] . In this context, Zheng et al.…”

“…[19] We also developed new catalysts for the dehydrogenative coupling of silanes with alcohols through the immobilization of Ag and Cr nanoparticles on the surface of an N-doped carbon support derived from the burning of chitosan. [20] In this context, Zheng et al used Pd nanoparticles immobilized in chitosan films for application in Suzuki coupling reactions. [21] When materials derived from chitosan were used as a support for new catalysts, this resulted in catalysts with good stability and easy recyclability.…”

Facile Synthesis of Ultra-Small Silver Nanoparticles Stabilized on Carbon Nanospheres for the Etherification of Silanes

“…A reported a novel N-doped carbon-based catalyst with silver and chromium nanostructures synthesized using chitosan as a precursor through biomass pyrolysis has been reported. [31] This catalyst has been used for the dehydrogenative coupling of various isomeric alcohols and hydrosilanes to produce silicon ethers. The catalyst exhibits excellent activity, good stability, and reusability.…”

Sustainable Synthesis of Silicon Precursors Coupled with Hydrogen Delivery Based on Circular Economy via Molecular Cobalt-Based Catalysts

“…As an alternative approach to address these current limitations, we turn to the dehydrogenative coupling of hydrosilanes with alcohols, which produces silyl ethers and hydrogen at low reaction temperatures, even at 0 °C − (Scheme A). Such silyl ethers are value-added chemical intermediates in the synthesis of silicones and hybrid organic–inorganic materials.…”