A new type of support 'bipyridine containing aromatic polyamide' to CuCl2 for synthesis of dimethyl carbonate (DMC) by oxidative carbonylation of methanol

A new type of heterogeneous catalyst, 'bipyridine containing aromatic polya mide' (poly( N,N'-bisphenylene-2,2'-bipyridine-4,4'-dicarboxylic amide, Bpy a)-CuCl2, for dimethyl carbonate (DMC) synthesis by oxidative carbonylation of methanol in the liquid-phase reaction was investigated. This catalyst s howed good performance thigh DMC yield and DMC selectivity), as in the case of poly(vinylpyridine) (PVP)-CuCl2. Bpya shows higher heat resistance than PVP, and thus Bpyrt-CuCl2 is considered to be more stable than PVP-CuCl2 u nder the reaction condition. Bpya-CuCl2 could be easily recycled after filt ration, and actually similar activity was found after three repetitions. Du ring the reaction, 20 similar to 30% of total CuCl2 was eliminated from the immobilized catalyst. Although the elimination of CuCl2 occurred considera bly in the initial step, it became slight during the reaction. The characte ristics of corrosion resistance of Bpya-CuCl2 was studied, and it became ob vious that corrosion is closely related to the trend of CuCl2 elimination. From these results, we proposed two types of reaction mechanism for the rea ction system. (C) 2000 Elsevier Science B.V. All rights reserved.