Barkaoui Sami, Wang Yanrong, Zhang Yifei, Gu Xinrui, Li Zhiwen, Wang Binli, Baiker Alfons, Li Gao, Zhao Zhen
Institute of Catalysis for Energy and Environment, College of Chemistry and Chemical Engineering, Shenyang Normal University, Shenyang 110034, China.
State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
iScience. 2024 Jun 12;27(7):110255. doi: 10.1016/j.isci.2024.110255. eCollection 2024 Jul 19.
The effect on catalytic behavior induced by different morphology of NiO supports has been investigated using the example of gold-catalyzed CO oxidation. Three NiO-supported nanogold consisting of nanogold deposited onto NiO nanorods (NiO-R), nanosheet (NiO-S), and nanodiscs (NiO-D) were prepared. Transmission electron microscopy(TEM)/Scanning transmission electron microscopy(STEM) investigations indicated that Au particles dominantly exposed Au(111) facets virtually independent of NiO architectures. Au/NiO-S displayed a normal Arrhenius-type behavior. Au/NiO-R and Au/NiO-D showed an atypical behavior, characterized by a U-shaped curve of activity vs. temperature, which is attributed to the carbonate accumulation on whose catalytically active sites. On Au/NiO-R, a stable CO-conversion rate of 1.78 mol g h at 30°C was achieved, which is among the higher rates reported so far for supported Au-based systems. DRIFTS measurement identified Au species as crucial CO adsorption sites promoting CO oxidation, and the catalytic CO oxidation should obey Mars-van Krevelen (<200°C) and Eley-Rideal mechanism (>240°C).
以金催化的CO氧化为例，研究了不同形貌的NiO载体对催化行为的影响。制备了三种负载在NiO上的纳米金，分别是沉积在NiO纳米棒（NiO-R）、纳米片（NiO-S）和纳米盘（NiO-D）上的纳米金。透射电子显微镜（TEM）/扫描透射电子显微镜（STEM）研究表明，金颗粒主要暴露Au(111)晶面，几乎与NiO结构无关。Au/NiO-S表现出正常的阿累尼乌斯型行为。Au/NiO-R和Au/NiO-D表现出非典型行为，其特征是活性与温度呈U形曲线，这归因于其催化活性位点上的碳酸盐积累。在Au/NiO-R上，30°C时实现了1.78 mol g h的稳定CO转化率，这是迄今为止报道的负载型金基体系中较高的转化率之一。漫反射红外傅里叶变换光谱（DRIFTS）测量确定金物种是促进CO氧化的关键CO吸附位点，催化CO氧化应遵循Mars-van Krevelen机制（<200°C）和Eley-Rideal机制（>240°C）。
