CuY zeolite catalysts prepared by ultrasonication-assisted ion-exchange for oxidative carbonylation of methanol to dimethyl carbonate

• Published in: Ultrasonics sonochemistry Vol. 44; pp. 146 - 151
• Main Authors: Woo, Je-Min, Seo, Jung Yoon, Kim, Hyunuk, Lee, Dong-Ho, Park, Young Cheol, Yi, Chang-Keun, Park, Yeong Seong, Moon, Jong-Ho
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.06.2018
• Subjects: Dimethyl carbonate; Oxidative carbonylation; Ultrasonication; Y zeolite; Oxidative carbonylation; Ultrasonication; Y zeolite; Dimethyl carbonate
• ISSN: 1350-4177; 1873-2828
• DOI: 10.1016/j.ultsonch.2018.02.013

•CuY zeolite catalysts were prepared by ultrasonication-assisted ion exchange.•The ultrasonication treatment improved surface area, acidity and Cu dispersity.•The enhanced Cu dispersity increased the ratio of active Cu+ species.•The obtained catalysts showed better performance for DMC synthesis via oxidative carbonylation. The influence of ultrasonication treatment on the catalytic performance of CuY zeolite catalysts was investigated for the liquid-phase oxidative carbonylation of methanol to dimethyl carbonate (DMC). The deammoniation method of NH4Y into HY zeolites was optimized and characterized by elemental analyzer, derivative thermogravimetry, Brunauer–Emmett–Teller (BET) analyzer, and powder X-ray diffractometry, revealing that the HY zeolite deammoniated at 400 °C presented the highest surface area, complete ammonium/proton ion exchange, and no structure collapse, rendering it the best support from all the prepared zeolites. CuY zeolites were prepared via aqueous phase ion exchange with the aid of ultrasonication. Upon ultrasonication, the Cu+ active centers were uniformly dispersed in the Y zeolites, penetrating the core of the zeolite particles in a very short time. In addition to enhancing the Cu dispersity, the ultrasonication treatment influenced the BET surface area, acid amount, Cu+/Cu2+ ratio, and also had a relatively small impact on the Cu loading. Consequently, adequate exposure to ultrasonication was able to increase the conversion rate of methanol into dimethyl carbonate up to 11.4% with a comparable DMC selectivity of 23.7%. This methanol conversion is 2.65 times higher than that obtained without the ultrasonication treatment.