Directed Assembly of Cuprous Oxide Nanocatalyst for CO2 Reduction Coupled to Heterobinuclear ZrOCoII Light Absorber in Mesoporous Silica

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• 作者：Wooyul Kim ; Heinz Frei
• 刊名：ACS Catalysis
• 出版年：2015
• 出版时间：September 4, 2015
• 年：2015
• 卷：5
• 期：9
• 页码：5627-5635
• 全文大小：488K
• ISSN：2155-5435

文摘

Hierarchical assembly of an oxo-bridged binuclear ZrOCo^II light absorber unit coupled to a cuprous oxide nanocluster catalyst for CO₂ reduction on mesoporous silica support is demonstrated. The proper positioning of the Cu oxide cluster was achieved by photodeposition of a [Cu(NCCH₃)₄]²⁺precursor by visible light excitation of the ZrOCo charge transfer chromophore, followed by mild calcination at 350 C. Illumination of the Cu_xO_y-ZrOCo unit so formed in the presence of a diethylamine electron donor resulted in the reduction of surface Cu centers to Cu⁰ as demonstrated by the characteristic infrared band of adsorbed ¹³CO probe molecules at 2056 cm^鈥?. For analogous Cu_xO_y-TiOCo^II units, the oxidation state makeup of the surface Cu centers was dominated by Cu^I, and the Cu⁰, Cu^I, and Cu^II composition was found to depend on the wavelength of MMCT excitation. The observed strong dependence of the CO₂ photoreduction yield on the oxidation state of the surface Cu centers directly proves that CO₂ is reduced on the Cu_xO_y surface, thus establishing that the ZrOCo^II unit functions as light absorber, donating electrons to the Cu_xO_y catalyst on whose surface CO₂ is reduced.