Fabrication of Yolk-Shell Cu@C Nanocomposites as High-Performance Catalysts in Oxidative Carbonylation of Methanol to Dimethyl Carbonate

Abstract

A facile way was developed to fabricate yolk-shell composites with tunable Cu cores encapsulated within hollow carbon spheres (Cu@C) with an average diameter about 210 nm and cavity size about 80 nm. During pyrolysis, the confined nanospace of hollow cavity ensures that the nucleation-and-growth process of Cu nanocrystals take place exclusively inside the cavities. The size of Cu cores can be easily tuned from 30 to 55 nm by varying the copper salt concentration. By deliberately creating shell porosity through KOH chemical activation, at an optimized KOH/HCS mass ratio of 1/4, the catalytic performance for the oxidative carbonylation of methanol to dimethyl carbonate (DMC) of the activated sample is enhanced remarkably with TOF up to 8.6 h−1 at methanol conversion of 17.1%. The activated yolk-shell catalyst shows promising catalytic properties involving the reusability with slight loss of catalytic activity and negligible leaching of activated components even after seven recycles, which is beneficial to the implementation of clean production for the eco-friendly chemical DMC thoroughly.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-017-2258-7) contains supplementary material, which is available to authorized users.

Making more with less: confinement effects for more sustainable chemical transformations

“…The Ren group reported a similar observation for the oxidative carbonylation of methanol to dimethyl carbonate. 103 It was found that larger void space in rattle-type Cu NPs on porous hollow carbon spheres structures led to higher activities compared to yolk–shell copper in hollow carbon spheres.…”

Ligand‐Free Yolk‐Shell Nanoparticles: Synthesis and Catalytic Applications

“…Several different types of LFYSNs were fabricated and used as model systems to determine their catalytic activity for several heterogeneous catalysis mainly for reduction and oxidation of nitro compounds, oxidation of alcohols and CO …”

Carbon-Supported Nitrogen-Doped Graphene-Wrapped Copper Nanoparticles: An Effective Catalyst for the Oxidative Carbonylation of Methanol

“…Carbon-supported copper is an effective catalyst in the oxidative carbonylation of methanol to dimethyl carbonate (DMC); however, in a slurry reaction system, the harsh reaction conditions often lead to agglomeration, loss, and oxidation of active copper species, which have a great influence on the catalytic activity and stability. In our previous studies, Cu@Carbon catalysts with controlled carbon shell thickness and Cu grain size have been prepared via one-step co-pyrolysis, ship-in-bottle, as well as hard template methods, , which displayed improved stability in the oxidative carbonylation of methanol. However, in a separated hollow carbon sphere, the problems of leaching and agglomeration of copper NPs still exist .…”