scholarly journals Enhanced Activity for CO Preferential Oxidation over CuO Catalysts Supported on Nanosized CeO2 with High Surface Area and Defects

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 884
Author(s):  
Lei Gong ◽  
Weiwei Jie ◽  
Yumeng Liu ◽  
Xinchen Lin ◽  
Wenyong Deng ◽  
...  

Nanosizedceria (n-CeO2) was synthesized by a facile method in 2-methylimidazolesolution. The characterization results of XRD, N2 adsorption-desorption, Raman and TEM indicate that n-CeO2 shows a regular size of 10 ± 1 nm, a high surface area of 130 m2·g−1 and oxygen vacancies on the surface. A series of CuO/n-CeO2 catalysts (CuCeOX) with different copper loading were prepared for the preferential oxidation of CO in H2-rich gases (CO-PROX). All CuCeOX catalysts exhibit a high catalytic activity due to the excellent structural properties of n-CeO2, over which the 100% conversion of CO is obtained at 120 °C. The catalytic activity of CuCeOX catalysts increases in the order of CuCeO12 < CuCeO3 < CuCeO6 < CuCeO9. It is in good agreement with the order of the amount of active Cu+ species, Ce3+ species and oxygen vacancies on these catalysts, suggesting that the strength of interaction between highly dispersed CuO species and n-CeO2 is the decisive factor for the activity. The stronger interaction results in the formation of more readily reducible copper species on CuCeO9, which shows the highest activity with high stability and the broadest temperature “window” for complete CO conversion (120–180 °C).

2020 ◽  
Vol 47 ◽  
pp. 223-230 ◽  
Author(s):  
Xian Yue ◽  
Junhui Xiang ◽  
Junyong Chen ◽  
Huaxin Li ◽  
Yunsheng Qiu ◽  
...  

NANO ◽  
2015 ◽  
Vol 10 (05) ◽  
pp. 1550075 ◽  
Author(s):  
Zhenghua Li ◽  
Heon Jong Jeong ◽  
Kumarsrinivasan Sivaranjani ◽  
Byung Jin Song ◽  
Su Bin Park ◽  
...  

Highly ordered mesoporous tungsten trioxide ( WO 3) with high surface area (75 m2/g) and well-defined mesopores were successfully prepared through a hard templating method using a mesoporous silica KIT-6 as a template and ( NH 4)6 H 2 W 12 O 40 ⋅ x H 2 O as a tungsten precursor. Oxidative desulfurization of a model oil with H 2 O 2 as the oxidant was carried out at 50°C under atmospheric pressure in order to analyze the catalytic activity. The desulfurization reactions were optimized by various kinds of reaction parameters such as H 2 O 2/ S molar ratio, reaction temperatures and series of sulfur-containing compounds [dibenzothiophene (DBT), benzothiophene (BT) and 4,6-dimethyl dibenzothiophene (4,6-DMBT)]. Excellent catalytic activity for the removal of the sulfur-containing compounds from the model oil was observed with mesoporous WO 3 catalyst, where the activity was maintained during 5 recycle tests without any regeneration process. The high catalytic activity and durability is mainly attributed to well-defined mesopores and high surface area of mesoporous WO 3 catalyst.


2013 ◽  
Vol 872 ◽  
pp. 10-14
Author(s):  
Alexey Pestryakov ◽  
Vitalii Petranovskii

Foam catalysts have physicochemical, gas-dynamic and catalytic characteristics exceeding the indices of the traditional granular and honeycomb catalysts. Nanopowders have high catalytic activity due to high surface area and special electronic state. Catalysts of new structural type nanopowders supported on foam metals and foam ceramics - have been tested in the process of deep oxidation of organic substances.


Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 135
Author(s):  
Zhibin Wen ◽  
Qianqian Zhu ◽  
Jiali Zhou ◽  
Shudi Zhao ◽  
Jinnan Wang ◽  
...  

Novel flower-shaped C-dots/Co3O4{111} with dual-reaction centers were constructed to improve the Fenton-like reaction activity and peroxymonosulfate (PMS) conversion to sulfate radicals. Due to the exposure of a high surface area and Co3O4{111} facets, flower-shaped C-dots/Co3O4{111} could provide more Co(II) for PMS activation than traditional spherical Co3O4{110}. Meanwhile, PMS was preferred for adsorption on Co3O4{111} facets because of a high adsorption energy and thereby facilitated the electron transfer from Co(II) to PMS. More importantly, the Co–O–C linkage between C-dots and Co3O4{111} induced the formation of the dual-reaction center, which promoted the production of reactive organic radicals (R•). PMS could be directly reduced to SO4−• by R• over C-dots. On the other hand, electron transferred from R• to Co via Co–O–C linkage could accelerate the redox of Co(II)/(III), avoiding the invalid decomposition of PMS. Thus, C-dots doped on Co3O4{111} improved the PMS conversion rate to SO4−• over the single active site, resulting in high turnover numbers (TONs). In addition, TPR analysis indicated that the optimal content of C-dots doped on Co3O4{111} is 2.5%. More than 99% of antibiotics and dyes were degraded over C-dots/Co3O4{111} within 10 min. Even after six cycles, C-dots/Co3O4{111} still remained a high catalytic activity.


2017 ◽  
Vol 4 (11) ◽  
pp. 1783-1790 ◽  
Author(s):  
Kai-Li Yan ◽  
Jing-Qi Chi ◽  
Zi-Zhang Liu ◽  
Bin Dong ◽  
Shan-Shan Lu ◽  
...  

Ag-doped mesoporous NiCoO nanorods as efficient and stable electrocatalysts for oxygen evolution reaction have been synthesized with desirable conductivity, high surface area and rich oxygen vacancies.


Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3602 ◽  
Author(s):  
Neel Narayan ◽  
Ashokkumar Meiyazhagan ◽  
Robert Vajtai

Nanoparticles play a significant role in various fields ranging from electronics to composite materials development. Among them, metal nanoparticles have attracted much attention in recent decades due to their high surface area, selectivity, tunable morphologies, and remarkable catalytic activity. In this review, we discuss various possibilities for the synthesis of different metal nanoparticles; specifically, we address some of the green synthesis approaches. In the second part of the paper, we review the catalytic performance of the most commonly used metal nanoparticles and we explore a few roadblocks to the commercialization of the developed metal nanoparticles as efficient catalysts.


2020 ◽  
Vol 8 (35) ◽  
pp. 18318-18326 ◽  
Author(s):  
Hailong Peng ◽  
Yangcenzi Xie ◽  
Zicheng Xie ◽  
Yunfeng Wu ◽  
Wenkun Zhu ◽  
...  

Porous high entropy alloy CrMnFeCoNi exhibited remarkable catalytic activity and stability toward p-nitrophenol hydrogenation. The enhanced catalytic performance not only resulted from the high surface area, but also from exposed high-index facets with terraces.


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