Coexistence of Cu() and Cu() in Cu ion-doped zeolitic imidazolate frameworks (ZIF-8) for the dehydrogenative coupling of silanes with alcohols

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 48; no. 44; pp. 16562 - 16568
• Main Authors: Dai, Yan, Xing, Peng, Cui, Xiaoqin, Li, Zhihong, Zhang, Xianming
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 28.11.2019
• Subjects: Alcohol; Alcohols; Coupling; Dehydrogenation; Ethanol; Metal-organic frameworks; Nanocrystals; Silanes; X ray photoelectron spectroscopy; Zeolites; Zinc oxide
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c9dt03181b

Recently, metal-ion-doped zeolitic imidazolate frameworks have gained considerable attention for their structure tailorability and potential catalytic applications. Herein, Cu ion-doped ZIF-8 nanocrystals were successfully prepared by the mechanical grinding of Cu(NO 3 ) 2 , ZnO and 2-methylimidazole (HMeIM) using ethanol as an additive. In contrast to the general view that only Cu( ii ) is present in Cu-doped ZIF-8, we found the coexistence of Cu( ii ) and Cu( i ) in this material, which was supported by XPS and X-ray induced Auger electron spectroscopy (XAES) characterizations. Moreover, ethanol might have acted as a reducer to induce the reduction of Cu( ii ) during synthesis. Due to the mixed valency of Cu ions, the Cu ion-doped ZIF-8 nanocrystals showed excellent catalytic performance in the dehydrogenative coupling of silanes with alcohols. Coexistence of Cu( ii ) and Cu( i ) in Cu ion doped ZIF-8 nanocrystals for dehydrogenative coupling.