scholarly journals Catalytic Decomposition of Nitrogen Oxides by Bimetallic Catalysts Synthesized by Dielectric Barrier Discharge Plasma Technology

2018 ◽  
Vol 53 ◽  
pp. 01032
Author(s):  
Libin Shi ◽  
Suitao Qi ◽  
Tianyou Jiao ◽  
Jifeng Qu ◽  
Xiao Tan ◽  
...  

Nitrous oxide (N2O) is a common greenhouse gas and urgent need to be contained. Direct catalytic decomposition of N2O by high activity catalyst into N2 and O2 is a low-cost and harmless method. Bimetallic catalysts show good catalytic activity in many classes of reactions, and plasma technologies, applied to prepare of catalyst, are considered to be a promising method. In our contribution, DBD cold plasma is applied to synthesize Rhodium and Cobalt bimetallic catalysts for catalytic N2O decomposition. The influence of cobalt and rhodium content on N2O decomposition activity shows that the optimal amount of metal is determined as 5wt. % cobalt and 0.5wt. % rhodium loaded on Al2O3. The best working voltage is determined as 18kV. The results indicated that the Rh/Al2O3 catalysts prepared by atmospheric-pressure DBD cold plasma showed smaller size and high dispersion of Rh particles, so that the metal-support interaction and the catalytic activity are enhanced. Atmospheric-pressure DBD cold plasma is proved to be an environmentally friendly and efficient method for preparing high performance Rhodium and Cobalt bimetallic catalysts for catalytic N2O decomposition.

2020 ◽  
Vol 8 (4) ◽  
pp. 429-439
Author(s):  
Ying Tao ◽  
Rong Li ◽  
Ai-Bin Huang ◽  
Yi-Ning Ma ◽  
Shi-Dong Ji ◽  
...  

AbstractAmong the transition metal oxide catalysts, manganese oxides have great potential for formaldehyde (HCHO) oxidation at ambient temperature because of their high activity, nontoxicity, low cost, and polybasic morphologies. In this work, a MnO2-based catalyst (M-MnO2) with an interconnected network structure was successfully synthesized by a one-step hydrothermal method. The M-MnO2 catalyst was composed of the main catalytic agent, δ-MnO2 nanosheets, dispersed in a nonactive framework material of γ-MnOOH nanowires. The catalytic activity of M-MnO2 for HCHO oxidation at room temperature was much higher than that of the pure δ-MnO2 nanosheets. This is attributed to the special interconnected network structure. The special interconnected network structure has high dispersion and specific surface area, which can provide more surface active oxygen species and higher surface hydroxyl groups to realize rapid decomposition of HCHO.


2015 ◽  
Vol 3 (7) ◽  
pp. 3450-3455 ◽  
Author(s):  
Wei Wu ◽  
Mei Lei ◽  
Shuanglei Yang ◽  
Li Zhou ◽  
Li Liu ◽  
...  

Copper-based alloy nanoparticles (NPs) have recently triggered much research interest for the development of low-cost and high-performance bimetallic catalysts that have industrial applications.


2021 ◽  
Vol 2076 (1) ◽  
pp. 012041
Author(s):  
Jinmiao Zhang ◽  
Mudi Zheng ◽  
Yuqing Zhou ◽  
Xingyuan Gao

Abstract Methane dry reforming reaction (DRM) can convert CO2 and CH4, two kinds of greenhouse gases with very stable chemical properties, to produce syngas, which can be used to synthesize valuable industrial products. Nickel-based catalysts have been widely used in DRM because of their low cost and good catalytic activity. However, nickel application is limited by such as high-temperature metal sintering, carbon deposition and catalyst poisoning, which restricts the industrial application in DRM reaction. Compared with single metal nickel, the selective doping of multi metals and supports shows higher catalytic activity and anti poisoning tolerance due to changing the chemical and structural properties of the catalyst by enhancing the alloy effect and the force between metal and support. This paper mainly reviews the catalysts with anti-coking, anti-sintering and anti-sulfur poisoning by tuning the metal-metal interaction and metal-support interaction (MSI) in DRM. The modification strategies in interfacial engineering and structure-performance relationship are discussed, and the existing difficulties and future development of Ni-based catalysts are proposed.


2019 ◽  
Author(s):  
Disha Jain

<p>Supported Ni catalysts are extensively studied for methane reforming due to their high catalytic activity and low cost. However, these catalysts undergo deactivation due to coke deposition and oxidation of Ni particles. In the present work, Ni and Pt substituted CoTiO<sub>3</sub> were synthesized and studied for steam (SRM) and dry (DRM) reforming of methane. The catalytic activity of monometallic and bimetallic Ni-Pt catalyst was compared for SRM and reducibility studies were done to highlight the change in metal-support interaction in the synthesized samples. Ex situ and in situ characterization were performed to understand the change in catalyst surface and the nature of surface intermediates formed during the reaction. Consequently, surface reaction mechanism was proposed and kinetic parameters were determined by fitting experimental data.</p><br>


2019 ◽  
Author(s):  
Disha Jain

<p>Supported Ni catalysts are extensively studied for methane reforming due to their high catalytic activity and low cost. However, these catalysts undergo deactivation due to coke deposition and oxidation of Ni particles. In the present work, Ni and Pt substituted CoTiO<sub>3</sub> were synthesized and studied for steam (SRM) and dry (DRM) reforming of methane. The catalytic activity of monometallic and bimetallic Ni-Pt catalyst was compared for SRM and reducibility studies were done to highlight the change in metal-support interaction in the synthesized samples. Ex situ and in situ characterization were performed to understand the change in catalyst surface and the nature of surface intermediates formed during the reaction. Consequently, surface reaction mechanism was proposed and kinetic parameters were determined by fitting experimental data.</p><br>


2021 ◽  
Vol 21 (10) ◽  
pp. 5319-5328
Author(s):  
Sha-Sha Luo ◽  
Yu-Meng Ma ◽  
Peng-Wei Li ◽  
Ming-Hua Tian ◽  
Qiao-Xia Li

Transition metal and nitrogen co-doped carbon-based catalysts (TM-N-C) have become the most promising catalysts for Pt/C due to their wide range of sources, low cost, high catalytic activity, excellent stability and strong resistance to poisoning, especially Fe–N–C metal-organic frameworks (MOFs), which are some of the most promising precursors for the preparation of Fe–N–C catalysts due to their inherent properties, such as their highly ordered three-dimensional framework structure, controlled porosity, and tuneable chemistry. Based on these, in this paper, different iron sources were added to synthesis a sort of zeolitic imidazole frameworks (ZIF-8). Then the imidazole salt in ZIF-8 was rearranged into high N-doped carbon by high-temperature pyrolysis to prepare the Fe–N–C catalyst. We studied the physical characteristics of the catalysts by different iron sources and their effects on the catalytic properties of the oxygen reduction reaction (ORR). From the point of morphology, various iron sources have a positive influence on maintaining the morphology of ZIF-8 polyhedron. Fe–N/C–Fe(NO3)3 has the same anion as zinc nitrate, and can maintain a polyhedral morphology after high-temperature calcination. It had the highest ORR catalytic activity compared to the other four catalyst materials, which proved that there is a certain relationship between morphology and performance. This paper will provide a useful reference and new models for the development of high-performance ORR catalysts without precious metals.


Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 161
Author(s):  
Fangtao Li ◽  
Xiaoxu Wang ◽  
Rongming Wang

As a typical two-dimensional (2D) MXene, Ti3C2O2 has been considered as a potential material for high-performance hydrogen evolution reaction (HER) catalyst, due to its anticorrosion and hydrophilic surface. However, it is still a challenge to improve the Ti3C2O2 surficial HER catalytic activity. In this work, we investigated the HER activity of Ti3C2O2 after the surface was doped with S, Se, and Te by the first principles method. The results indicated that the HER activity of Ti3C2O2 is improved after being doped with S, Se, Te because the Gibbs free energy of hydrogen adsorption (ΔGH) is increased from −2.19 eV to 0.08 eV. Furthermore, we also found that the ΔGH of Ti3C2O2 increased from 0.182 eV to 0.08 eV with the doping concentration varied from 5.5% to 16.7%. The HER catalytic activity improvement of Ti3C2O2 is attributed to the local crystal structure distortion in catalytic active sites and Fermi level shift leads to the p-d orbital hybridization. Our results pave a new avenue for preparing a low-cost and high performance HER catalyst.


Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1437 ◽  
Author(s):  
Zhuang Li ◽  
Jingsen Zhang ◽  
Hongyang Wang ◽  
Zhihui Li ◽  
Xiuling Zhang ◽  
...  

Treatment with atmospheric-pressure (AP) hydrogen cold plasma is an effective method for preparing highly active supported metal catalytic materials. However, this technique typically uses H2 as working gas, which is explosive and difficult to transport. This study proposes the use of PdCl2 as a Pd precursor and activated carbon as the support to fabricate Pd/C catalytic materials (Pd/C-EP-Ar) by using ethanol—which is renewable, easily stored, and safe—combined with AP cold plasma (AP ethanol cold plasma) followed by calcination in Ar gas at 550 °C for 2 h. Both Pd/C-EP and Pd/C-HP fabricated using AP ethanol and hydrogen cold plasma (without calcination in Ar gas) respectively, exhibit low CO oxidation reactivity. The activity of Pd/C-EP is lower than Pd/C-HP, which is mainly ascribed to the carbon layer formed by ethanol decomposition during plasma treatment. However, the 100% CO conversion temperature (T100) of Pd/C-EP-Ar is 140 °C, which is similar to that of Pd/C-HP-Ar fabricated using AP hydrogen cold plasma (calcined in Ar gas at 550 °C for 2 h). The characterization results of X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy indicated that the carbon layer formed by ethanol decomposition enhanced the interaction of metal nanoparticles to the support, and a high Pd/C atomic ratio was obtained. This was beneficial to the high CO oxidation performance. This work provides a safe method for synthesizing high-performance Pd/C catalytic materials avoiding the use of H2, which is explosive and difficult to transport.


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