Quantitative Coassembly for Precise Synthesis of Mesoporous Nanospheres with Pore Structure‐Dependent Catalytic Performance

2021 ◽  
pp. 2103130
Author(s):  
Shu‐Chuan Mei ◽  
Xian‐Hong Rui ◽  
Liang Li ◽  
Gui‐Xiang Huang ◽  
Xiao‐Qiang Pan ◽  
...  
2020 ◽  
Vol 16 ◽  
Author(s):  
Anping Wang ◽  
Heng Zhang ◽  
Hu Li ◽  
Song Yang

Background: With the gradual decrease of fossil energy, the development of alternatives to fossil energy has attracted more and more attention. Biodiesel is considered to be the most potent alternative to fossil energy, mainly due to its green, renewable and biodegradable advantages. The stable, efficient and reusable catalysts are undoubtedly the most critical in the preparation of biodiesel. Among them, nanoporous carbon-based acidic materials are very important biodiesel catalysts. Objective: The latest advances of acidic nanoporous carbon catalysts in biodiesel production was reviewed. Methods: Biodiesel is mainly synthesized by esterification and transesterification. Due to the important role of nanoporous carbon-based acidic materials in the catalytic preparation of biodiesel, we focused on the synthesis, physical and chemical properties, catalytic performance and reusability. Results: Acidic catalytic materials have a good catalytic performance for high acid value feedstocks. However, the preparation of biodiesel with acid catalyst requires relatively strict reaction conditions. The application of nanoporous acidic carbon-based materials, due to the support of carbon-based framework, makes the catalyst have good stability and unique pore structure, accelerates the reaction mass transfer speed and accelerates the reaction. Conclusion: Nanoporous carbon-based acidic catalysts have the advantages of suitable pore structure, high active sites, and high stability. In order to make these catalytic processes more efficient, environmentally friendly and low cost, it is an important research direction for the future biodiesel catalysts to develop new catalytic materials with high specific surface area, suitable pore size, high acid density, and excellent performance.


Author(s):  
Sungsik Park ◽  
Gakuji Sato ◽  
Ryota Osuga ◽  
Yong Wang ◽  
Yoshihiro Kubota ◽  
...  

The Analyst ◽  
2019 ◽  
Vol 144 (4) ◽  
pp. 1205-1209 ◽  
Author(s):  
Chi Zhang ◽  
Caiyun Kong ◽  
Qingyun Liu ◽  
Zhengbo Chen

We herein present a simple, low-cost, and ultrasensitive colorimetric sensing strategy for the detection of mercury ions (Hg2+) that takes advantage of the natural pore structure in rose petals to encapsulate gold nanoparticles (AuNPs).


2019 ◽  
Vol 58 (14) ◽  
pp. 5543-5551 ◽  
Author(s):  
Feiying Tang ◽  
Liqiang Wang ◽  
Guangji Zhang ◽  
Min Zhang ◽  
You-Nian Liu

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Michael K. Albretsen ◽  
Baiyu Huang ◽  
Kamyar Keyvanloo ◽  
Brian F. Woodfield ◽  
Calvin H. Bartholomew ◽  
...  

A novel solvent deficient precipitation (SDP) method to produce nanoparticles was studied for its potential in Fischer-Tropsch synthesis (FTS) catalysis. Using Fe(NO3)3·9H2O as the iron-containing precursor, this method produces ferrihydrite particles which are then dried, calcined, reduced, and carbidized to form the active catalytic phase for FTS. Six different drying profiles, including final drying temperatures ranging between 80 and 150°C, were used to investigate the effect of ammonium nitrate (AN), a major by-product of reaction between Fe(NO3)3·9H2O and NH4HCO3 in the SDP method. Since AN has two phase-transitions within this range of drying temperatures, three different AN phases can exist during the drying of the catalyst precursors. These AN phases, along with physical changes occurring during the phase transitions, may affect the pore structure and the agglomeration of ferrihydrite crystallites, suggesting possible reasons for the observed differences in catalytic performance. Catalysts dried at 130°C showed the highest FTS rate and the lowest methane selectivity. In general, better catalytic performance is related to the AN phase present during drying as follows: phase III > phase II > phase I. However, within each AN phase, lower drying temperatures led to better catalytic properties.


2015 ◽  
Vol 5 (3) ◽  
pp. 1588-1597 ◽  
Author(s):  
Zhenxin Xu ◽  
Ning Wang ◽  
Wei Chu ◽  
Jie Deng ◽  
Shizhong Luo

The dual confinement effects from alumina and LDH precursors produced a new nanoplates-on-pore structure with a uniform distribution and smaller size of Ni nanoparticles (NPs) for the LDOs/γ-Al2O3, while enhanced catalytic performance and better resistance to sintering and coking.


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