Investigation of the interaction between Cu(acac)2 and NH4Y in the preparation of chlorine-free CuY catalysts for the oxidative carbonylation of methanol to a fuel additive. Issue 124 (27th November 2015)

• Record Type: Journal Article
• Authors: Wang, Yuchun; Zheng, Huayan; Li, Zhong; Xie, Kechang
• Is Part Of: RSC advances. Volume 5:Issue 124(2015)
• Page Start: 102323
• Page End: 102331
• Publication Date: 2015-11-27
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra19941g
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : The high temperature anhydrous interaction between Cu(acac)2 and NH4 Y was investigated to prepare a chlorine-free CuY catalyst for the oxidative carbonylation of methanol to DMC. The Cu/NH4 Y-400 catalyst shows superior catalytic activity. Abstract : The high temperature anhydrous interaction between copper(ii ) acetylacetonate Cu(acac)2 and NH4 Y was investigated to prepare a chlorine-free CuY catalyst for the oxidative carbonylation of methanol to dimethyl carbonate. When a physical mixture of Cu(acac)2 and NH4 Y is heated from ambient temperature to 230 °C, Cu(acac)2 firstly sublimates and then is adsorbed immediately onto the surface of the Y zeolite. Simultaneously the ion exchange between Cu(acac)2 and NH4 Y occurs at about 174 °C. During the activation process from 230 to 500 °C, the exchanged Cu 2+ is reduced to a Cu + active center, and the adsorbed and unreacted Cu(acac)2 on the NH4 Y surface decomposes to nano-CuO. For NaY zeolite, no solid state ion-exchange occurs between Cu(acac)2 and NaY during the heat treatment and only CuO exists on the Cu/NaY catalyst surface. While for HY zeolite, there is less ion-exchanged Cu + in the supercages. The Cu/NaY catalyst has no catalytic activity and the Cu/HY catalyst exhibits lower activity than the Cu/NH4 Y catalyst. Strong evidence is provided that during heat treatment, a solid state ion-exchange between Cu(acac)2 and NH4 Y occurs and makes more of the Cu + located in the supercages accessible to reactants.