Wang Yanan, Liu Sihang, Pei Chunlei, Fu Qiang, Zhao Zhi-Jian, Mu Rentao, Gong Jinlong
Key Laboratory for Green Chemical Technology of Ministry of Education , School of Chemical Engineering and Technology , Tianjin University; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300072 , China . Email:
State Key Laboratory of Catalysis , iChEM , Dalian Institute of Chemical Physics , Chinese Academy of Sciences , Dalian 116023 , China.
Chem Sci. 2019 Sep 27;10(45):10531-10536. doi: 10.1039/c9sc03119g. eCollection 2019 Dec 7.
In heterogeneous catalysis, it is widely believed that the surface states of catalyst supports can strongly influence the catalytic performance, because active components are generally anchored on supports. This paper describes a detailed understanding of the influence of surface defects of TiO supports on the catalytic properties of Pt catalysts. Pt was deposited on reduced (r-), hydroxylated (h-), and oxidized (o-) TiO surfaces, respectively, and the different surface states of TiO not only lead to differences in metal dispersion, but also distinct electronic interactions between the metal and the support. The highest reactivity for catalytic CO oxidation can be achieved over the Pt catalyst supported on reduced TiO with surface oxygen vacancies. The turnover frequency (TOF) of this catalyst is determined to be ∼11 times higher than that of Pt supported on oxidized TiO. More importantly, the reactivity is seen to increase in the sequence of Pt/o-TiO < Pt/h-TiO < Pt/r-TiO, which is well consistent with the trend of the calculated Bader charge of Pt.
在多相催化中，人们普遍认为催化剂载体的表面状态会强烈影响催化性能，因为活性组分通常锚定在载体上。本文详细阐述了TiO载体表面缺陷对Pt催化剂催化性能的影响。Pt分别沉积在还原态（r-）、羟基化态（h-）和氧化态（o-）的TiO表面上，TiO的不同表面状态不仅导致金属分散性的差异，还导致金属与载体之间不同的电子相互作用。在具有表面氧空位的还原态TiO负载的Pt催化剂上，可实现最高的催化CO氧化反应活性。该催化剂的周转频率（TOF）被确定比负载在氧化态TiO上的Pt高出约11倍。更重要的是，反应活性按Pt/o-TiO < Pt/h-TiO < Pt/r-TiO的顺序增加，这与计算得到的Pt的巴德电荷趋势非常一致。
