scholarly journals High catalytic activity for formaldehyde oxidation of an interconnected network structure composed of δ-MnO2 nanosheets and γ-MnOOH nanowires

2020 ◽  
Vol 8 (4) ◽  
pp. 429-439
Author(s):  
Ying Tao ◽  
Rong Li ◽  
Ai-Bin Huang ◽  
Yi-Ning Ma ◽  
Shi-Dong Ji ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Network Structure ◽  
Manganese Oxides ◽  
Active Oxygen Species ◽  
Low Cost ◽  
High Dispersion ◽  
Hydroxyl Groups ◽  
High Catalytic Activity ◽  
Interconnected Network ◽  
Surface Hydroxyl

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.

scholarly journals Synergistic Effects of Co3O4-CeO2 Nanoparticles towards Catalytic Oxidation of Aromatic Hydrocarbons: A Study in Association with Carbon Monoxide and Humidity

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Trung Dang-Bao ◽  
Hong Phuong Phan ◽  
Phung Anh Nguyen ◽  
Pham Phuong Trang Vo ◽  
Van Tien Huynh ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Catalytic Oxidation ◽  
Synergistic Effects ◽  
Active Oxygen Species ◽  
High Dispersion ◽  
High Catalytic Activity ◽  
Impregnation Method ◽  
Temperature Programmed ◽  
The Stability

In this study, a series of Co3O4-CeO2 nanocomposites with various Co3O4 loading were fabricated by the impregnation method using cobalt(II) acetate as the cobalt precursor for the treatment of benzene, toluene, ethylbenzene, and xylene (BTEX). The as-prepared Co3O4-CeO2 nanocomposites were thoroughly characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brumauer-Emmett-Teller (BET), hydrogen temperature-programmed reduction (H2-TPR), and temperature-programmed desorption (O2-TPD). The excellent reproduction of active oxygen species caused by the high dispersion of Co3O4 crystals on the CeO2 supports was established. In addition, the reduction peaks of Co3O4-CeO2 nanocomposites were found at much lower temperatures compared to pure CeO2, considering their unique redox property influencing on the high catalytic activity. Among the characterized materials, the 5.0 wt.% Co3O4 supported on CeO2 (5.0Co–Ce) was the best system for catalytic oxidation of xylene, along with excellent performances in the cases of benzene, ethylbenzene, and toluene. Its catalytic activity increased in the order: benzene < xylene < ethylbenzene < toluene . Furthermore, the addition of carbon monoxide (CO) as a coreactant permitted to improve the catalytic performances in such oxidations as well as the stability of as-prepared catalysts, even under humid conditions.

Hollow structured CoSn(OH)6-supported Pt for effective room-temperature oxidation of gaseous formaldehyde

2016 ◽  
Vol 09 (06) ◽  
pp. 1642009 ◽  
Author(s):  
Jing Zhou ◽  
Yong Zhao ◽  
Lifan Qin ◽  
Chen Zeng ◽  
Wei Xiao
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Room Temperature ◽  
Synergetic Effect ◽  
Hollow Structure ◽  
Pt Nanoparticles ◽  
Hydroxyl Groups ◽  
High Catalytic Activity ◽  
Temperature Oxidation ◽  
X Ray

Uniform CoSn(OH)6 hollow nanoboxes and the derivative with Pt loading (Pt/CoSn(OH)6) were herein synthesized and characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). SEM and TEM analyses showed that CoSn(OH)6 possessed mesoporous hollow structure and Pt nanoparticles with size of 2–8[Formula: see text]nm were uniformly dispersed on the surface of CoSn(OH)6 nanoboxes. The performances of the catalysts for the formaldehyde (HCHO) removal at room temperature were evaluated. These Pt/CoSn(OH)6 catalysts exhibited a remarkable catalytic activity as well as stability for room-temperature oxidative decomposition of gaseous HCHO, while the corresponding CoSn(OH)6 only showed adsorption. The synergetic effect between the highly dispersed Pt nanoparticles and the CoSn(OH)6 nanoboxes with mesoporous hollow structure, a large surface area and abundant surface hydroxyl groups is considered to be the main reason for the observed high catalytic activity of Pt/CoSn(OH)6.

Molten salts-assisted synthesis of special open-cell Fe, N co-doped porous carbon as an efficient electrocatalyst for zinc-air batteries

2021 ◽  
Author(s):  
Xiaoying Gao ◽  
Xuan Xie ◽  
Kanjun Sun ◽  
Xiaofei Lei ◽  
Tianyu Hou ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Porous Carbon ◽  
Molten Salts ◽  
Low Cost ◽  
High Catalytic Activity ◽  
Open Cell ◽  
Co Doped ◽  
Excellent Stability ◽  
Zinc Air Batteries

Fe, N co-doped carbon electrocatalyst is one of the most attractive alternatives to Pt/C catalysts due to its high catalytic activity, excellent stability and low cost. However, obtaining stable and...

scholarly journals Improving the Performance of Zn-Air Batteries with N-Doped Electroexfoliated Graphene

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2115 ◽  
Author(s):  
Anna Ilnicka ◽  
Malgorzata Skorupska ◽  
Piotr Romanowski ◽  
Piotr Kamedulski ◽  
Jerzy P. Lukaszewicz
Keyword(s):  
Catalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Noble Metals ◽  
Electrode Materials ◽  
Low Cost ◽  
Rapid Development ◽  
Reduction Reaction ◽  
Graphene Sheets ◽  
High Catalytic Activity ◽  
Energy Storage Devices

The constantly growing demand for active, durable, and low-cost electrocatalysts usable in energy storage devices, such as supercapacitors or electrodes in metal-air batteries, has triggered the rapid development of heteroatom-doped carbon materials, which would, among other things, exhibit high catalytic activity in the oxygen reduction reaction (ORR). In this article, a method of synthesizing nitrogen-doped graphene is proposed. Few-layered graphene sheets (FL-graphene) were prepared by electrochemical exfoliation of commercial graphite in a Na2SO4 electrolyte with added calcium carbonate as a separator of newly-exfoliated FL-graphene sheets. Exfoliated FL-graphene was impregnated with a suspension of green algae used as a nitrogen carrier. Impregnated FL-graphene was carbonized at a high temperature under the flow of nitrogen. The N-doped FL-graphene was characterized through instrumental methods: high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. Electrochemical performance was determined using cyclic voltamperometry and linear sweep voltamperometry to check catalytic activity in ORR. The N-doped electroexfoliated FL-graphene obeyed the four-electron transfer pathways, leading us to further test these materials as electrode components in rechargeable zinc-air batteries. The obtained results for Zn-air batteries are very important for future development of industry, because the proposed graphene electrode materials do not contain any heavy and noble metals in their composition.

scholarly journals Bifunctional electrochemical properties of La0.8Sr0.2Co0.8M0.2O3-δ (M= Ni, Fe, Mn, Cu): efficient elemental doping based on structural and pH-dependent study

2021 ◽  
Author(s):  
Junfang Cheng ◽  
Pandian Ganesan ◽  
Ziling Wang ◽  
Ming Zhang ◽  
Guozhu Zhang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Oxygen Reduction Reaction ◽  
Oxygen Evolution Reaction ◽  
Low Cost ◽  
Perovskite Oxides ◽  
Reduction Reaction ◽  
High Catalytic Activity ◽  
Suitable Candidate ◽  
Ph Dependent ◽  
Elemental Doping

Perovskite oxides with a low cost and high catalytic activity are considered as suitable candidate for oxygen evolution reaction (OER)/oxygen reduction reaction (ORR), whereas most of them favor only either...

scholarly journals Anionic polyelectrolytes in titanosilicate molecular sieve synthesis towards simultaneously accomplishing low production cost and high catalytic activity

RSC Advances ◽  
2018 ◽  
Vol 8 (38) ◽  
pp. 21363-21368 ◽  
Author(s):  
Kairui Fu ◽  
Jingui Wang ◽  
Yichen Wang ◽  
Yuanchao Shao ◽  
Jiaqi Zhu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieve ◽  
Production Cost ◽  
Low Cost ◽  
High Catalytic Activity ◽  
Titanium Silicalite ◽  
Diffusion Restriction

Anionic polyelectrolytes can help to directly achieve low-cost, titanium-rich, diffusion restriction-free and 100%-yield titanium silicalite-1.

Sulfur doping enhanced desorption of intermediates on NiCoP for efficient alkaline hydrogen evolution

Nanoscale ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 1985-1993 ◽  
Author(s):  
Yuyang Qi ◽  
Long Zhang ◽  
Lan Sun ◽  
Guanjun Chen ◽  
Qiaomei Luo ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
High Stability ◽  
Low Cost ◽  
High Catalytic Activity ◽  
Sulfur Doping

Electrocatalysts with high catalytic activity, high stability and low cost are critical to the hydrogen evolution reaction (HER).

Effect of Bimetallic Doping in Cobalt Titanate for Methane Reforming

2019 ◽  
Author(s):  
Disha Jain
Keyword(s):  
Catalytic Activity ◽  
Low Cost ◽  
Coke Deposition ◽  
Ex Situ ◽  
Pt Catalyst ◽  
High Catalytic Activity ◽  
Methane Reforming ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Surface Intermediates

<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>

Effect of Bimetallic Doping in Cobalt Titanate for Methane Reforming

2019 ◽  
Author(s):  
Disha Jain
Keyword(s):  
Catalytic Activity ◽  
Low Cost ◽  
Coke Deposition ◽  
Ex Situ ◽  
Pt Catalyst ◽  
High Catalytic Activity ◽  
Methane Reforming ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Surface Intermediates

<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>

Effect of Different Iron Sources on In-Situ Growth of Zeolitic Imidazolate Frameworks-8: For Efficient Oxygen Reduction Electrocatalysts

2021 ◽  
Vol 21 (10) ◽  
pp. 5319-5328
Author(s):  
Sha-Sha Luo ◽  
Yu-Meng Ma ◽  
Peng-Wei Li ◽  
Ming-Hua Tian ◽  
Qiao-Xia Li
Keyword(s):  
Catalytic Activity ◽  
High Temperature ◽  
Oxygen Reduction ◽  
High Performance ◽  
Low Cost ◽  
Three Dimensional ◽  
Precious Metals ◽  
High Catalytic Activity ◽  
Zeolitic Imidazolate Frameworks ◽  
Wide Range

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.

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