Partially Reduced CuO Nanoparticles as Multicomponent Cu-Based Catalysts for the Rochow Reaction

Abstract

We report the application of partially reduced CuO nanoparticles as Cu-based catalysts for dimethyldichlorosilane (M2) synthesis via the Rochow reaction. The CuO nanoparticles (50–100 nm) were synthesized by a simple precipitation method and partially reduced in a H2/N2 mixture gas to obtain the Cu-based catalyst containing different Cu species of CuO, Cu2O, and Cu. It was found that the composition of the samples could be tailored by varying the volume ratio of H2/N2 at the given reduction temperature and time. Compared to the synthesized CuO and Cu nanoparticles, as well as the commercial CuO microparticles, these multicomponent Cu-based catalysts, particularly for the CuO–Cu2O–Cu catalyst, showed much higher M2 selectivity and Si conversion in the Rochow reaction. The enhanced catalytic performance is attributed to the smaller particle size and the synergistic effect among the different components. The work would help to develop novel ternary Cu-based catalysts for organosilane synthesis.

Scalable Synthesis of Interconnected Porous Silicon/Carbon Composites by the Rochow Reaction as High‐Performance Anodes of Lithium Ion Batteries

“…After the catalytic reaction, porous Si/C particles with a size distribution of 2–60 μm (Figure 1 c) are formed, which exhibit a coherent macroscopic porous network structure with a pore size of 1–5 μm (Figure 1 d). The SEM images of other porous Si/C samples (Supporting Information, Figure S1) obtained under different reaction conditions also show that Si/C materials with internal connected porous structures can be readily prepared at a relatively low temperature of 325–450 °C using different Cu‐based catalysts, such as Cu 2 O,7a CuO,7b Cu/Cu 2 O/CuO,7c and CuCl 7d. After simple post treatments, Si/C‐900 (Supporting Information, Figure S2a), Si/C+C‐900 (Figure S2b), Si/C+C‐900‐HF (Figure S2c), and Si‐400 (Figure S2d) also show porous structure.…”

Recent Advances in Rochow‐Müller Process Research: Driving to Molecular Catalysis and to A More Sustainable Silicone Industry

“…Typically, various Cu‐based phases, such as elementary Cu, CuCl, Cu 2 O, CuO and even Cu−Cu 2 O−CuO have been explored to catalyze Rochow‐Müller process, as shown in Figure . Although most researchers still use “catalyst” to describe the role of Cu or its compound (called “coppers”), the term of “catalyst” in Rochow‐Müller process has aroused a lot of controversies.…”

“…Until now, it has not been very clear about the exact reason, probably because the applied reaction conditions and used reactors influenced or suppressed the reaction performances, or Cu might be truly inactive along with certain reactors and reaction parameters. Statistically, under the same reaction conditions, Cu exhibits the lowest M2 selectivity and Si conversion compared with other Cu oxide phases according to the publications, thus only few papers are reported to test and explore the catalytic performance and mechanism of Cu . Zhang et al reported that a kind of porous cubic Cu was more active for Rochow‐Müller process because porosity within micro‐particles greatly enhanced gas transportation and formation of active Cu−Si phase .…”

“…It has been widely shown that there are synergistic effects among Cu, Cu 2 O, and CuO, as many patents and papers reported that under conventional reaction conditions, neither Cu, Cu 2 O, nor CuO alone achieved satisfactory performance, except for the Cu−Cu 2 O−CuO ternary system . Liu et al reported a kind of ternary‐phase nanoparticles with the optimum weight proportion of 18.1: 53.0: 28.9 (Cu: Cu 2 O: CuO), which achieved 74.5 % of M2 selectivity and 23.4 % of Si conversion . What's more, the Cu‐based flakes composed of Cu−Cu 2 O−CuO with a weight ratio of 28: 41: 31 were reported to reach a high catalytic performance of 82.3 % M2 selectivity and 32.5 % Si conversion .…”

Controllably oxidized copper flakes as multicomponent copper-based catalysts for the Rochow reaction

“…However, all the above Cu-based catalysts are always in the micrometer size and the synergistically catalytic effect between different components is not fully understood yet. More recently, Liu et al, 34 prepared nanosized Cu-based catalysts with multicomponent of Cu, Cu 2 O, and CuO by partial reduction of CuO nanoparticles in hydrogen. However, a large scale manufacture of such catalysts seems impossible considering the preparation cost.…”