Acta Chimica Sinica ›› 2021, Vol. 79 ›› Issue (4): 490-499.DOI: 10.6023/A20110511 Previous Articles     Next Articles



阮曼a,b,c,d, 赵艳霞a,c,d,*(), 何圣贵a,b,c,d,*()   

  1. a 中国科学院化学研究所 分子动态与稳态结构国家重点实验室 北京 100190
    b 中国科学院大学 北京 100049
    c 北京分子科学国家研究中心 北京 100190
    d 中国科学院分子科学科教融合卓越创新中心 北京 100190
  • 投稿日期:2020-11-05 发布日期:2020-12-31
  • 通讯作者: 赵艳霞, 何圣贵
  • 基金资助:
    北京市自然科学基金(2182092); 王宽诚教育基金和中国科学院青年创新促进会基金(2018041)

Study on the Reaction of Nanosized Yttrium Oxide Cluster Anions with n-Butane in the Gas Phase

Man Ruana,b,c,d, Yan-Xia Zhaoa,c,d,*(), Sheng-Gui Hea,b,c,d,*()   

  1. a State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
    b University of Chinese Academy of Sciences, Beijing 100049, China
    c Beijing National Laboratory for Molecular Sciences, Beijing 100190, China
    d CAS Research/Education Center of Excellence in Molecular Sciences, Beijing 100190, China
  • Received:2020-11-05 Published:2020-12-31
  • Contact: Yan-Xia Zhao, Sheng-Gui He
  • About author:
  • Supported by:
    Beijing Natural Science Foundation(2182092); K. C. Wong Education Foundation, and Youth Innovation Promotion Association, Chinese Academy of Sciences(2018041)

Investigation on the reactions of atomically precise transition metal oxide nanoparticles with small molecules can not only identify the property evolution of nanoparticles with respect to the continuum change of size and composition, but also improve our understanding of the formation mechanism of reactive oxygen species [e.g., atomic oxygen radical anions (O-• radicals)] over oxide surface. Yttrium oxide cluster anions YxOy- (x≤50,y≤76) with different oxygen deficiencies (Δ≡2y–1–3x, Δ=0~5) and Y xOyF- (x≤49,y≤74) with Δ=1 [Δ≡(2y+1)–1–3x] have been prepared by laser ablation in an O2 background and reacted with alkane molecules (n-butane) in a fast flow reactor. The reactions of mass-selected small-sized YxOy- (x≤8) clusters withn-butane were investigated in a linear ion trap reactor. Time-of-flight mass spectrometer was used to detect the cluster distribution before and after the reactions. The observation of (Y2O3)NOH- (N=1~25), (Y2O3)NYO4H- (N=1, 3~24), and (Y2O3)NYO2FH- (N=1~24) products suggest that (Y2O3)NO- (∆=1;N=1~25), (Y2O3)NYO4- (∆=4;N=1, 3~24) and (Y2O3)NYO2F- (Δ=1;N=1~24) can bring about hydrogen-atom abstraction (HAA) from n-butane. The reactivity of (Y2O3)NO-, (Y2O3)NYO2F- and (Y2O3)NYO4- clusters are significantly size-dependent and the highest reactivity was observed for N=3 (Y6O10-, Y7O11F-, and Y7O13-). Density functional theory (DFT) calculations were performed to study the geometrical structures and unpaired spin densities of (Y2O3)NO- (N=1~4), (Y2O3)NYO2F- (N=1~3), and (Y2O3)NYO4- (N=1, 3, 4) clusters that were found to contain O-• radicals as active centers to abstract hydrogen atoms from n-butane, in agreement with the experiments. The results imply that the O-• radicals which had been proved to be present in the small yttrium oxide clusters with Δ=1 or 4 are well preserved in the yttrium oxide nanoparticles. (Y 2O3)NYO4- (∆=4;N=1, 3~24) and (Y2O3)NYO2F- (∆=1;N=1~24) can be considered to be generated by the adsorption of an O2 molecule or F onto the unreactive singlet (Y2O3)NYO2- (∆=0;N=1~24). The studies on gas-phase clusters suggest that adsorption of O2 molecule or F atom onto unreactive metal oxide clusters will result in the generation of O-• radical (O2-+O2→O-•+O2-• and O2-+F→O-•+F-). This work not only reveals the new mechanisms of the formation of O-• radical on metal oxide surfaces, but also provides new insights into the design of novel transition metal oxide-based catalysts.

Key words: yttrium oxide cluster, nanosize, reactivity, atomic oxygen radical anion, time-of-flight mass spectrometer