Hybrid sol–gel double metal cyanide catalysts for the copolymerisation of styrene oxide and CO2

Abstract

Hybrid sol-gel catalysts of zinc hexacyanocobaltate and SiO 2 were prepared by co-precipitation of the double metal cyanide with silica. Hybrid catalysts prepared at moderately acidic conditions showed the best performance with respect to activity, selectivity and stability. The hybrid sol-gel materials displayed high catalytic activity for the copolymerisation of styrene oxide and carbon dioxide (up to 650 mol SO (mol Zn h) −1 ) and high productivity (575 g Polymer g Catalyst −1 ). They also displayed good selectivity to the polymeric product (80-87%), while only little cyclic styrene carbonate was formed as side product. A detailed electron microscopy study of the hybrid sol-gel materials showed that the active phase consisted of thin platelets containing the metals in a molar ratio n Zn /n Co = 2.1, whereby the double metal cyanide was closely associated with silica.

Double metal cyanide catalyst prepared using H3Co(CN)6for high carbonate fraction and molecular weight control in carbon dioxide/propylene oxide copolymerization

“…We demonstrated that the carbonate fraction could be increased up to 64% by employing a dual catalytic system composed of a DMC and a Salen‐cobalt(III) complex . In this work, we report the simple preparation of a new type of DMC catalyst, which exhibits a high CO 2 incorporation (up to 67 mol %) and thus provides a successful derivatization of the conventional DMC catalyst …”

Greener synthesis of dimethyl carbonate using a novel ceria–zirconia oxide/graphene nanocomposite catalyst

“…The conversion of CO 2 into value added chemicals has been widely investigated in an attempt to reduce the atmospheric levels of CO 2 . Recently, CO 2 has attracted great interests as an environmentally benign building block in the chemical industry due to its non-toxic, non-flammable and recyclable properties [1][2][3][4]. However, CO 2 is a very stable compound as the carbon atom is in the most oxidized form and thermodynamically stable [5] and therefore large energy input is required to transform CO 2 .…”

Facile preparation and synergy study of DMC/ZnGA composite catalyst for the synthesis of oligo (propylene‐carbonate) diols

“…And no obvious decomposition and changes of structure was observed at 200 °C in all samples (Figure S1 and Figure S2). Notably, accounting for the influence of Mn on f CO2 ’ and CU’ value, it was more preferable to evaluate the CO 2 activation ability with f CO2 and the by‐product PC was generated from the back‐biting process of growing chain which also should be taken into account.…”