Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.
J Phys Chem A. 2011 Jun 2;115(21):5238-46. doi: 10.1021/jp200984r. Epub 2011 May 10.
Zirconium oxide cluster cations and anions are produced by laser ablation and reacted with CO in a fast flow reactor. The CO adsorption products Zr(x)O(y)CO(+) are observed for most of the generated cationic clusters (Zr(x)O(y)(+) = Zr(2)O(5,6)(+), Zr(3)O(7,8)(+), Zr(4)O(9,10)(+)...) while only specific anionic systems (Zr(x)O(y)(-) = Zr(3)O(7)(-), Zr(4)O(9)(-)...) absorb CO to produce Zr(x)O(y)CO(-). To study how the CO molecule is adsorbed on the clusters, the Zr(x)O(y)CO(±) products are mass-selected by a time-of-flight mass spectrometer (TOF-MS) and collided with a crossed helium beam. The fragment ions from collision-induced dissociation (CID) are detected by a secondary TOF-MS. Loss of CO and CO(2) is observed upon the collision of the helium beam with Zr(x)O(y)CO(+) and Zr(x)O(2x+1)CO(-), respectively. Density functional theory calculations indicate that oxidative and nonoxidative adsorption of CO takes place over Zr(3)O(7)(-) and Zr(3)O(7)(+), respectively. This is consistent with the CID experiments.
氧化锆团簇阳离子和阴离子通过激光烧蚀产生，并在快速流动反应器中与 CO 反应。观察到大多数生成的阳离子簇（Zr(x)O(y)(+) = Zr(2)O(5,6)(+), Zr(3)O(7,8)(+), Zr(4)O(9,10)(+)...）与 CO 吸附产物 Zr(x)O(y)CO(+)，而只有特定的阴离子体系（Zr(x)O(y)(-) = Zr(3)O(7)(-), Zr(4)O(9)(-)...）吸收 CO 以产生 Zr(x)O(y)CO(-)。为了研究 CO 分子如何吸附在团簇上，通过飞行时间质谱仪（TOF-MS）对 Zr(x)O(y)CO(±)产物进行质量选择，并与交叉氦束碰撞。通过二次 TOF-MS 检测到碰撞诱导解离（CID）的碎片离子。当氦束与 Zr(x)O(y)CO(+)和 Zr(x)O(2x+1)CO(-)碰撞时，分别观察到 CO 和 CO(2)的损失。密度泛函理论计算表明，CO 在 Zr(3)O(7)(-)上发生氧化和非氧化吸附，而在 Zr(3)O(7)(+)上发生非氧化吸附。这与 CID 实验一致。
