Crystal plane dependent dopant migration that boosts catalytic oxidation

2018 ◽  
Vol 8 (23) ◽  
pp. 6084-6090 ◽  
Author(s):  
Ruixue Wang ◽  
Jingjing Wei ◽  
Huiying Wei ◽  
Yanzhao Yang
Keyword(s):  
Catalytic Oxidation ◽  
Catalytic Performance ◽  
Crystal Plane ◽  
Catalyst Supports ◽  
Iron Species ◽  
Crystallographic Facets

CeO2 rods with {110} facets and cubes with {100} facets were utilized as catalyst supports to probe the effect of crystallographic facets on the iron species and the structure-dependent catalytic performance.

scholarly journals Electron donation of non-oxide supports boosts O2 activation on nano-platinum catalysts

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Gan ◽  
Jingxiu Yang ◽  
David Morris ◽  
Xuefeng Chu ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Pt Nanoparticles ◽  
Catalytic Performance ◽  
Nitrogen Vacancy ◽  
Innovative Strategy ◽  
Oxide Supports ◽  
Heterogeneous Catalytic ◽  
Highly Active ◽  
Electron Sink ◽  
Nitrogen Vacancies

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.

The Synthesis of Iron Oxides with Different Phases or Exposure Crystal Planes and their Catalytic Property for Propene Oxidation

2012 ◽  
Vol 463-464 ◽  
pp. 189-193
Author(s):  
Kong Zhai Li ◽  
Masaaki Haneda ◽  
Masakuni Ozawa
Keyword(s):  
Catalytic Activity ◽  
Iron Oxides ◽  
Catalytic Property ◽  
Significant Influence ◽  
Catalytic Performance ◽  
Selective Growth ◽  
Crystal Plane ◽  
Low Density ◽  
Fe2o3 Nanoparticles ◽  
Propene Oxidation

Maghemite (γ-FeSubscript text2OSubscript text3) and hematite (α-Fe2O3) nanoparticles with various dominant exposure crystal planes were prepared by several different methods. The structure and the reducibility of these materials were investigated by XRD, Raman and H2-TPR technologies, and their catalytic performance for propene oxidation was also discussed. The maghemite (γ-FeSubscript text2OSubscript text3) showed a better reducibility than hematite (α-FeSubscript text2OSubscript text3), but its activity for propene oxidation is relatively lower. The exposure crystal plane of hematite has a significant influence on its catalytic activity for propene oxidation. Among the prepared four samples, the hematite-1 sample showed the best activity. The selective growth of any planes with a relative low density of Fe atoms for the α-FeSubscript text2OSubscript text3 catalyst would lead to an obvious decrease in the catalytic activity.

Effect of the crystal plane figure on the catalytic performance of MnO2for the total oxidation of propane

CrystEngComm ◽  
2015 ◽  
Vol 17 (15) ◽  
pp. 3005-3014 ◽  
Author(s):  
Yujie Xie ◽  
Yanyan Yu ◽  
Xueqing Gong ◽  
Yun Guo ◽  
Yanglong Guo ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Crystal Plane ◽  
Plane Figure ◽  
Total Oxidation

scholarly journals Pt-Promoted Tungsten Carbide Nanostructures on Mesoporous Pinewood-Derived Activated Carbon for Catalytic Oxidation of Formaldehyde at Low Temperatures

2020 ◽  
Vol 1 (2) ◽  
pp. 86-105
Author(s):  
Qiangu Yan ◽  
Zhiyong Cai
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Relative Humidity ◽  
Tungsten Carbide ◽  
Catalytic Oxidation ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Inert Atmosphere ◽  
Bet Surface Area ◽  
Formaldehyde Concentration

Tungsten carbide (WC) nanostructures were prepared by carbothermal reduction (CR) of tungsten-impregnated pinewood-derived activated carbon (AC) at 1000 °C under an inert atmosphere. Brunauer-Emmet-Teller (BET) surface area, pore structures of the AC, and catalyst samples were evaluated by N2 adsorption-desorption experiments. The structures of the catalysts were characterized using X-ray powder diffraction (XRD). The morphologies and particle structures of the synthesized WC nanoparticles were investigated by field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). The WC/AC material was used as support of the platinum catalysts for catalytic oxidation of formaldehyde (HCHO) from interior sources. Pt-WC/AC catalysts with different platinum loadings were assessed for the catalytic oxidation of HCHO at low temperature. The catalytic performance was found to be significantly influenced by reaction temperature, initial formaldehyde concentration, relative humidity, and space velocity. The testing results demonstrated that HCHO can be totally oxidized by the 1 wt% Pt-WC/AC catalyst in the gas hourly space velocity (GHSV) = 50,000 h−1 at 30 °C with a relative humidity (RH) of 40%.

Catalytic oxidation of methyl bromide using ruthenium-based catalysts

2016 ◽  
Vol 6 (12) ◽  
pp. 4337-4344 ◽  
Author(s):  
Xiaolong Liu ◽  
Junlin Zeng ◽  
Jian Wang ◽  
Wenbo Shi ◽  
Tingyu Zhu
Keyword(s):  
Thermal Stability ◽  
Catalytic Oxidation ◽  
Methyl Bromide ◽  
Catalytic Performance ◽  
Product Selectivity

Ruthenium-based catalysts Ru/TiO2, Ru/SiO2, Ru/γ-Al2O3, and Ru/ZrO2 were prepared and evaluated for CH3Br oxidation, and Ru/TiO2 showed the best catalytic performance. Product selectivity, thermal stability, and anti-moisture properties were also studied.

Intensified-Fenton process for the treatment of phenol aqueous solutions

2014 ◽  
Vol 71 (3) ◽  
pp. 359-365 ◽  
Author(s):  
M. Isabel Pariente ◽  
Raúl Molina ◽  
Juan Antonio Melero ◽  
Juan Ángel Botas ◽  
Fernando Martínez
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Heterogeneous Catalyst ◽  
Reaction Temperature ◽  
Catalytic Performance ◽  
Fenton Process ◽  
Iron Species ◽  
Iron Extraction ◽  
Dissolved Iron ◽  
Iron Leaching

An intensified-Fenton process for the treatment of phenol aqueous solutions has been studied as a continuous catalytic wet hydrogen peroxide oxidation system. This process consists of coupling the catalytic activity of a heterogeneous Fenton-like catalyst with the homogeneous contribution of its dissolved iron species. Agglomerated mesoporous SBA-15 silica-supported iron oxide (Fe2O3/SBA-15) material was used as heterogeneous catalyst. The influence of the reaction temperature and the initial hydrogen peroxide dosages was studied in order to minimize the operation cost of the process. The catalytic performance of the process was assessed in terms of total organic carbon (TOC) and hydrogen peroxide conversions. Likewise, the stability of the solid Fenton-like catalyst was also evaluated in terms of the dissolved iron species. The increase of the reaction temperature enhanced the TOC conversion and reduced the iron leaching from the heterogeneous catalyst. These results were related to the degradation of oxalic acid as responsible for iron extraction by formation of soluble stable iron complexes into the aqueous medium. Finally, the use of a moderate hydrogen peroxide concentration (2.6 g/L) and milder temperatures (80–120 °C) has led to remarkable results of TOC and phenol reductions as well as oxidant efficiency through the intensified-Fenton process.

Catalytic performance of vanadia-doped titania-pillared clay for the selective catalytic oxidation of H2S

2009 ◽  
Vol 15 (2) ◽  
pp. 207-211 ◽  
Author(s):  
Kanattukara Vijayan Bineesh ◽  
Sang-Yun Kim ◽  
Balasamy Rabindran Jermy ◽  
Dae-Won Park
Keyword(s):  
Catalytic Oxidation ◽  
Catalytic Performance ◽  
Pillared Clay ◽  
Selective Catalytic Oxidation ◽  
Doped Titania

scholarly journals Removal of VOCs by Ozone: n-Alkane Oxidation under Mild Conditions

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 506
Author(s):  
Alina I. Mytareva ◽  
Igor S. Mashkovsky ◽  
Sergey A. Kanaev ◽  
Dmitriy A. Bokarev ◽  
Galina N. Baeva ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Oxygen Vacancies ◽  
Oxide Catalyst ◽  
Catalytic Performance ◽  
High Concentration ◽  
Volatile Organic ◽  
Negative Effect ◽  
Manganese Oxide Catalyst ◽  
Conventional Solution ◽  
Al2o3 Catalyst

Volatile organic compounds (VOCs) have a negative effect on both humans and the environment; therefore, it is crucial to minimize their emission. The conventional solution is the catalytic oxidation of VOCs by air; however, in some cases this method requires relatively high temperatures. Thus, the oxidation of short-chain alkanes, which demonstrate the lowest reactivity among VOCs, starts at 250–350 °C. This research deals with the ozone catalytic oxidation (OZCO) of alkanes at temperatures as low as 25–200 °C using an alumina-supported manganese oxide catalyst. Our data demonstrate that oxidation can be significantly accelerated in the presence of a small amount of O3. In particular, it was found that n-C4H10 can be readily oxidized by an air/O3 mixture over the Mn/Al2O3 catalyst at temperatures as low as 25 °C. According to the characterization data (SEM-EDX, XRD, H2-TPR, and XPS) the superior catalytic performance of the Mn/Al2O3 catalyst in OZCO stems from a high concentration of Mn2O3 species and oxygen vacancies.

Crystal-Plane-Controlled Surface Restructuring and Catalytic Performance of Oxide Nanocrystals

2011 ◽  
Vol 123 (51) ◽  
pp. 12502-12506 ◽  
Author(s):  
Huizhi Bao ◽  
Wenhua Zhang ◽  
Qing Hua ◽  
Zhiquan Jiang ◽  
Jinlong Yang ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Crystal Plane ◽  
Surface Restructuring
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