scholarly journals Catalytic Performance of Toluene Combustion over Pt Nanoparticles Supported on Pore-Modified Macro-Meso-Microporous Zeolite Foam

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 30 ◽  
Author(s):  
Sibei Zou ◽  
Mingyuan Zhang ◽  
Shengpeng Mo ◽  
Hairong Cheng ◽  
Mingli Fu ◽  
...  

Herein, to investigate the pore effect on toluene catalytic oxidation activity, novel supports for Pt nanoparticles—ZSM-5 foam (ZF) fabricated using polyurethane foam (PUF) templates and pore-modified ZSM-5 foam (ZF-D) treated by acid etching, comparing with conventional ZSM-5 and pore-modified ZSM-5 (ZSM-5-D), were successfully synthesized. Pt nanoparticles were loaded on series ZSM-5 supports by the impregnation method. The Pt loaded on ZF-D (Pt/ZF-D) showed the highest activity of toluene catalytic combustion (i.e., T90 = 158 °C), with extraordinary stability and an anti-coking ability. Based on various catalysts characterizations, the unique macropores of ZF facilitated the process of acid etching as compared to conventional ZSM-5. The mesopores volume of ZF-D significantly increased due to acid etching, which enlarged toluene adsorption capacity and led to a better Pt distribution since some Pt nanoparticles were immobilized into some mesopores. Specifically, the microporous distribution was centered in the range of 0.7–0.8 nm close to the molecular diameter of toluene (ca. 0.67 nm), which was key to the increasing toluene diffusion rate due to pore levitation effect of catalysts and accessibility of metal. Furthermore, the reducibility of Pt nanoparticles was improved on Pt/ZF-D, which enhanced the activity of toluene catalytic oxidation.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Gan ◽  
Jingxiu Yang ◽  
David Morris ◽  
Xuefeng Chu ◽  
Peng Zhang ◽  
...  

AbstractActivation of O2 is a critical step in heterogeneous catalytic oxidation. Here, the concept of increased electron donors induced by nitrogen vacancy is adopted to propose an efficient strategy to develop highly active and stable catalysts for molecular O2 activation. Carbon nitride with nitrogen vacancies is prepared to serve as a support as well as electron sink to construct a synergistic catalyst with Pt nanoparticles. Extensive characterizations combined with the first-principles calculations reveal that nitrogen vacancies with excess electrons could effectively stabilize metallic Pt nanoparticles by strong p-d coupling. The Pt atoms and the dangling carbon atoms surround the vacancy can synergistically donate electrons to the antibonding orbital of the adsorbed O2. This synergistic catalyst shows great enhancement of catalytic performance and durability in toluene oxidation. The introduction of electron-rich non-oxide substrate is an innovative strategy to develop active Pt-based oxidation catalysts, which could be conceivably extended to a variety of metal-based catalysts for catalytic oxidation.


2021 ◽  
Author(s):  
Lei Yi ◽  
Jinke Xie ◽  
Caiting Li ◽  
Jian Shan ◽  
Yingyun Liu ◽  
...  

Abstract A battery of agricultural straw derived biomass activated carbons supported LaOx modified MnOx (LaMn/BACs) was prepared by a facile impregnation method and then tested for the efficiency of simultaneous abatement of NO and Hg0. 15%LaMn/BAC manifested excellent removal efficiency of Hg0 (100%) and NO (86.7%) at 180 °C, which also exhibited splendid resistance to SO2 and H2O. The interaction between Hg0 removal and NO removal was explored, thereinto Hg0 removal had no influence on NO removal, while NO removal preponderated over Hg0 removal. The inhibitory effect of NH3 was greater than the accelerative effect of NO and O2 on Hg0 removal. The physicochemical characterization of related samples were characterized by SEM, XRD, BET, H2-TPR, NH3-TPD and XPS. After incorporating suitable LaOx into 15%Mn/BAC, the synergistic effect between LaOx and MnOx contributed to the improvement of BET surface area and total pore volume, the promotion of redox ability, surface active oxygen species and acid sites, inhibiting the crystallization of MnOx. 15%LaMn/BAC has the best catalytic oxidation activity at low temperature. That might be answerable for superior performance and preferable tolerance to SO2 and H2O. Finally, the principle of catalytic oxidation was also discussesed in this article.


Langmuir ◽  
1992 ◽  
Vol 8 (11) ◽  
pp. 2720-2723 ◽  
Author(s):  
H. Fischer ◽  
G. Schulz-Ekloff ◽  
T. Buck ◽  
D. Woehrle ◽  
M. Vassileva ◽  
...  

Author(s):  
Junan Gao ◽  
Song Gao ◽  
Jun Wei ◽  
Hong Zhao ◽  
Jie Zhang

In this paper, the catalytic combustion of DMDS (dimethyl disulfide, CH3SSCH3) over bimetallic supported catalysts were investigated. It was confirmed that Cu/γ-Al2O3-CeO2 showed best catalytic performance among the five single-metal catalysts. Furthermore, six different metals were separately added into Cu/γ-Al2O3-CeO2 to investigate the promoting effect. The experiments revealed Pt as the most effective promoter and the the best catalytic performance was achieved as the adding amount of 0.3 wt%. The characterization results indicated that high activity and resistance to sulfur poisoning of Cu-Pt/γ-Al2O3-CeO2 could be attributed to the synergistic effect between Cu and Pt.


2012 ◽  
Vol 512-515 ◽  
pp. 1601-1606 ◽  
Author(s):  
Ran Ran Ding ◽  
Jia Nan Hu ◽  
Rui Sheng Hu ◽  
Ying Liu ◽  
Ling Jie Wang

Supported rare earth double perovskite (La2MnNiO6) oxide catalysts were prepared by incipient wet impregnation method for methane catalytic combustion, and effects of the support (Al2O3, ZrO2 and MgO) were investigated. The loaded catalysts were characterized by means of XRD, TPR, SEM techniques and their catalytic activities were tested by complete methane oxidation. Depending on the different oxide carrier (e.g. Al2O3, MgO and ZrO2), catalysts have different catalytic properties, because the interaction of metal oxide-support will affect both redox property and dispersity of the active phase. The results on catalysts have shown that the dispersion on Al2O3 and MgO supports had an effect to enhance the catalytic performances of the catalysts that had been treated at 1100 oC. The activity of ZrO2 supported catalyst significantly decreases when calcination temperature at is 1100 oC. The dispersity of the active phase and the nature of the oxide carrier played an important role in the catalytic performance.


2018 ◽  
Vol 47 (39) ◽  
pp. 14060-14069 ◽  
Author(s):  
Shu-Li Feng ◽  
Ying Lu ◽  
Yue-Xian Zhang ◽  
Fang Su ◽  
Xiao-Jing Sang ◽  
...  

Three new Strandberg-type polyoxometalate TM-(PhP)2Mo5 supports for immobilizing HRP showed high adsorption capacity and good catalytic oxidation activity.


Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 742 ◽  
Author(s):  
Jingsen Zhang ◽  
Lanbo Di ◽  
Feng Yu ◽  
Dongzhi Duan ◽  
Xiuling Zhang

Commercial TiO2 (P25) supported gold (Au/P25) attracts increasing attention. In this work, atmospheric-pressure (AP) cold plasma was employed to activate the Au/P25-As catalyst prepared by a modified impregnation method. The influence of cold plasma working gas (oxygen, argon, hydrogen, and air) on the structure and performance of the obtained Au/P25 catalysts was investigated. X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), and X-ray spectroscopy (XPS) were adopted to characterize the Au/P25 catalysts. CO oxidation was used as model reaction probe to test the Au/P25 catalyst. XRD results reveal that supporting gold and AP cold plasma activation have little effect on the P25 support. CO oxidation activity over the Au/P25 catalysts follows the order: Au/P25-O2P > Au/P25-As > Au/P25-ArP ≈ Au/P25-H2P > Au/P25-AirP. Au/P25-AirP presents the poorest CO oxidation catalytic activity among the Au/P25 catalysts, which may be ascribed to the larger size of gold nanoparticles, low concentration of active [O]s, as well as the poisoning [NOx]s. The poor catalytic performance of Au/P25-ArP and Au/P25-H2P is ascribed to the lower concentration of [O]s species. 100% CO conversion temperatures for Au/P25-O2P is 40 °C, which is 30 °C lower than that over the as-prepared Au/P25-As catalyst. The excellent CO oxidation activity over Au/P25-O2P is mainly attributed to the efficient decomposition of gold precursor species, small size of gold nanoparticles, and the high concentration of [O]s species.


Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 994 ◽  
Author(s):  
Junan Gao ◽  
Song Gao ◽  
Jun Wei ◽  
Hong Zhao ◽  
Jie Zhang

In this paper, the catalytic combustion of DMDS (dimethyl disulfide, CH3SSCH3) over bimetallic supported catalysts were investigated. It was confirmed that Cu/γ-Al2O3-CeO2 showed best catalytic performance among the five single-metal catalysts. Furthermore, six different metals were separately added into Cu/γ-Al2O3-CeO2 to investigate the promoting effect. The experiments revealed Pt as the most effective promoter and the best catalytic performance was achieved as the adding amount of 0.3 wt%. The characterization results indicated that high activity and resistance to sulfur poisoning of Cu-Pt/γ-Al2O3-CeO2 could be attributed to the synergistic effect between Cu and Pt.


2018 ◽  
Vol 5 (8) ◽  
pp. 180587 ◽  
Author(s):  
Xiaotong Zhang ◽  
Ying Yan

Catalytic combustion of isopropanol in the structured fixed-bed reactor was investigated over Co–ZSM-5 zeolite membrane catalysts. Firstly, ZSM-5 zeolite membrane catalysts with different Si/Al ratios were coated onto the surface of stainless steel fibres via secondary growth method and wet lay-up paper-making method. Then, cobalt oxides were loaded onto the zeolite membranes by impregnation method. The performance of catalytic combustion of isopropanol was conducted over the prepared zeolite membrane catalysts, and the experimental results showed that the catalyst with infinite Si/Al ratio has the highest catalytic activity for the combustion with the lowest T 90 of isopropanol (285°C). Finally, the effects of bed structure, feed concentration, gas hourly space velocity and reaction temperature on the catalytic performance were investigated to analyse the kinetics of isopropanol over the catalyst with infinite Si/Al ratio in the structured fixed-bed reactor. The results showed that the longer residence time could cause higher reaction contact efficiency of isopropanol combustion. T 90 of isopropanol can be dramatically decreased by 105°C in the fixed-bed reactor packed with Co–ZSM-5 zeolite membrane catalysts, compared to the fixed-bed reactor packed with granular catalyst.


2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Xiaoya Gao ◽  
Qian Guo ◽  
Yuan Zhou ◽  
Dedong He ◽  
Yongming Luo

In this work, a series of natural mordenite-supported platinum (Pt) catalysts were prepared by a facile two-step method, namely, treatment of natural mordenite and then the loading of Pt nanoparticles. The acid-alkali-treated natural mordenite-supported Pt samples (1% Pt/MORn-H-OH) exhibited the highly enhanced catalytic oxidation activity of formaldehyde (HCHO) at room temperature. XRD results showed that the crystalline phase of the mordenite did not change significantly in 1% Pt/MORn-H-OH catalyst. However, the acid-alkali treatment endowed the Pt particles excellent dispersion with the smallest diameter of 2.8 nm in a high loading content, which contributed to the optimal catalytic activity of 1% Pt/MORn-H-OH.


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