Insight into Morphology‐Dependent Catalytic Performance of CuO/CeO2 Produced by Tannic Acid for Efficient Hydrogenation of 4‐Nitrophenol

Author(s):  
Junqing Ye ◽  
Shuaijun Wang ◽  
Gen Li ◽  
Bin He ◽  
Xinyan Chen ◽  
...  
Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 488
Author(s):  
Katarzyna Stawicka ◽  
Maciej Trejda ◽  
Maria Ziolek

Niobium containing SBA-15 was prepared by two methods: impregnation with different amounts of ammonium niobate(V) oxalate (Nb-15/SBA-15 and Nb-25/SBA-15 containing 15 wt.% and 25 wt.% of Nb, respectively) and mixing of mesoporous silica with Nb2O5 followed by heating at 500 °C (Nb2O5/SBA-15). The use of these two procedures allowed obtaining materials with different textural/surface properties determined by N2 adsorption/desorption isotherms, XRD, UV-Vis, pyridine, and NO adsorption combined with FTIR spectroscopy. Nb2O5/SBA-15 contained exclusively crystalline Nb2O5 on the SBA-15 surface, whereas the materials prepared by impregnation had both metal oxide and niobium incorporated into the silica matrix. The niobium species localized in silica framework generated Brønsted (BAS) and Lewis (LAS) acid sites. The inclusion of niobium into SBA-15 skeleton was crucial for the achievement of high catalytic performance. The strongest BAS were on Nb-25/SBA-15, whereas the highest concentration of BAS and LAS was on Nb-15/SBA-15 surface. Nb2O5/SBA-15 material possessed only weak LAS and BAS. The presence of the strongest BAS (Nb-25/SBA-15) resulted in the highest dehydration activity, whereas a high concentration of BAS was unfavorable. Silylation of niobium catalysts prepared by impregnation reduced the number of acidic sites and significantly increased acrolein yield and selectivity (from ca. 43% selectivity for Nb-25/SBA-15 to ca. 61% for silylated sample). This was accompanied by a considerable decrease in coke formation (from 47% selectivity for Nb-25/SBA-15 to 27% for silylated material).


2021 ◽  
Vol 616 ◽  
pp. 118081
Author(s):  
Pavlo I. Kyriienko ◽  
Olga V. Larina ◽  
Dmytro Yu. Balakin ◽  
Anatolii O. Stetsuk ◽  
Yurii M. Nychiporuk ◽  
...  

Author(s):  
Xiaoning Ren ◽  
Panqing Yin ◽  
Jun Liang ◽  
Xiangjian Liu ◽  
Wugen Zhan ◽  
...  

The tannic acid-based modular-assembly strategy for building inorganic–biological hybrids is studied regarding the aspects of the material suitability, loading effect, and biocompatibility.


2020 ◽  
Vol 89 (1) ◽  
pp. 10103
Author(s):  
Honglin Li ◽  
Yuting Cui ◽  
Haijun Luo ◽  
Wanjun Li

Efforts to efficiently use of the next generation 2-dimension (2D) structured monolayers is getting a lot of attention for their excellent properties recently. In this work, we composite the blue phosphorus (BP) and monolayer GeX (X = C/H/Se) via van der Waals force (vdW) interaction to obtain well defined type-II band alignment heterostructures. A systematic theoretic study is conducted to explore the interlayer coupling effects and the bands re-alignment of BP-GeX (X = C/H/Se) heterostructure after the strain imposed. To devise usable and efficient materials to degrade pollutant or used as a potential photovoltaic cell material, previous researches have proved that using 2D materials as components is a feasible way to obtain high performance. Here, we prudently present a comprehensive investigation on the BP and GeX (X = C/H/Se) with different twisted angles via first-principles calculation to lay a theoretical framework on the band alignment and carriers' separation. It reveals that the intrinsic electronic properties of BP and GeX are roughly preserved in the corresponding heterostructures. Upon strain applied, band alignment can be flexibly manipulated by varying external imposed strain. The heterostructures can maintain type-II character within a certain strain range, and thus the carriers are spatially separated to different portions. This work not only provides a deep insight into the construction of the heterostructure, but presents a new possibility to search for a flexible and feasible approach to promote its catalytic performance. The corresponding results would provide meaningful guidelines for designing 2D structure based novel materials.


Author(s):  
Youlin Li ◽  
Yu Hu ◽  
Wenqiao You ◽  
Guangming Zhou ◽  
Guilong Peng

Abstract Activated carbon/CuO (AC/CuO) composites was prepared through a facile one-step hydrothermal method and used as a bifunctional material for adsorption and catalysis degradation of bisphenol A (BPA). The composite was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray powder diffraction (XRD). The obtained AC/CuO exhibited excellent adsorption and catalytic performance. The maximum adsorption capacity of BPA on the AC/CuO was 319.03 mg/g according to the Langmuir fitting. At an initial BPA concentration of 20 mg/L, the BPA degradation efficiencies were maintained above 96% for 15 min by using 20 mg/L AC/CuO and 2 mM peroxymonosulfate (PMS). Moreover, the relationship between adsorption and catalytic degradation was also investigated. The results indicated that the pre-adsorption disfavored the degradation reaction. This work not only provides a novel preparation method for AC/CuO catalyst, but also gives a deeper insight into the mechanisms between adsorption and catalytic degradation.


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