CuY Zeolite Catalyzed Oxidative Carbonylation of Methanol to Dimethyl Carbonate: Comparative Investigation of Reduction Method

CuY zeolite is a promising catalyst for oxidative carbonylation of methanol to dimethyl carbonate (DMC). In this work, auto-reduction at high temperature and vapor-induced reduction were comparatively investigated to activate the CuY precursors. XPS, XRD as well as CO adsorption demonstrated that methanol as reduction agent can achieve a high proportion of Cu(I) and avoid the formation of Cu(0) as far as possible, which is responsible for the enhanced DMC yield. CuY catalysts were prepared by ammonia evaporation followed by two reduction methods. Compared with the high temperature autoreduction in inert atmosphere, methanol vapor-induced reduction could achieve a higher Cu(I) content that results in an enhanced activity in dimethyl carbonate formation.