催化作用
化学
氧气
价(化学)
催化氧化
无机化学
氧化还原
密度泛函理论
过渡金属
镧
金属
多相催化
吸附
物理化学
空位缺陷
部分氧化
色散(光学)
吸附
化学工程
纳米笼
尖晶石
氧化态
自动氧化
铈
氯乙烯
活化能
氯化物
氧化物
苯胺
再分配(选举)
光化学
作者
Hongliang Zhang,Haijie Cao,Guanghao Li,Valérie Meille,Sonia Gil,Chuanhui Zhang
标识
DOI:10.1016/j.jcat.2025.116524
摘要
• ZIF-67 sacrificial template enables homogeneous dispersion of La dopants. • La incorporation improves redox properties and promotes oxygen vacancy formation. • In-situ DRIFT measurements identify key intermediates in catalytic vinyl chloride oxidation. • DFT calculations reveal the electronic structure modulation and oxygen activation facilitation. The development of high-performance transition metal oxides catalysts is one of the promising topics in the application field of chlorinated volatile organic pollutants abatement. Herein, La-incorporated Co 3 O 4 catalysts with variable lanthanum contents were prepared by using ZIF-67 as the sacrificial template, giving rise to successful oxygen vacancies engineering and the construction of a hollow-cage structure. Experimental results revealed that La-incorporation into Co 3 O 4 structure remarkably improved the catalytic activity for vinyl chloride (VC) oxidation with a close dependence on the lanthanum content. Among all catalysts, 5La-Co (the molar ratio of La in the total metal was 5 %) exhibited an optimal catalytic activity achieving 90 % of VC conversion at 276 °C in comparison with the pristine Co 3 O 4 (0La-Co in this work) at 290 °C. Moreover, this catalyst presented an adequately high catalytic stability under complex humid conditions. Characterization results and DFT calculations revealed the modulation of the intrinsic electronic structure and spinel lattice parameters on the Co 3 O 4 matrix by La incorporation, leading to the valence states redistribution of Co 3+ /Co 2+ , more oxygen vacancy generation originating from the lower formation energy (1.86 eV), and more abundant surface oxygen species originating from the lower gas-phase oxygen adsorption energy (−1.59 eV). All these properties enabled the observable catalytic activity enhancement of La-incorporated Co 3 O 4 catalysts. In addition, the formation of enol groups and carboxylic acid as key organic intermediates during the VC oxidation process was highlighted by the in-situ DRIFT spectroscopy. The more plentiful surface oxygen species available on La-incorporated Co 3 O 4 catalyst surface were favorable to the formation and further oxidation of these organic intermediates.
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