scholarly journals Effect of Preparation Methods on the Performance of Pt/TiO2 Catalysts for the Catalytic Oxidation of Carbon Monoxide in Simulated Sintering Flue Gas

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 804
Author(s):  
Jianyu Cai ◽  
Zehui Yu ◽  
Jian Li
Keyword(s):  
Particle Size ◽  
Catalytic Activity ◽  
Flue Gas ◽  
Ball Mill ◽  
Water Resistance ◽  
Physical Structure ◽  
Impregnation Method ◽  
Oxidation Of Co ◽  
Preparation Methods ◽  
So2 Adsorption

A series of Pt/TiO2 catalysts were prepared by the impregnation (IM), dry ball mill (DB), or wet ball mill (WB) methods, and their catalytic activity for the oxidation of CO was evaluated. The structure and redox properties of the catalysts were investigated by N2 desorption, XRD, SEM, TEM, XPS, H2-TPR, SO2-TPD, and CO chemisorption analysis. It was determined that the preparation method affects the physical structure of the catalyst and the particle size and dispersion of Pt on the catalyst surface. The catalyst prepared by the impregnation method had a more suitable physical structure than the other catalysts, with a smaller particle size, a higher dispersion of Pt on the surface, and the lowest strength of SO2 adsorption. Pt/TiO2(IM) catalysts presented the best catalytic activity for the oxidation of CO in simulated sintering flue gas at 140 °C, as well as better sulfur and water resistance with simulated sintering flue gas containing 50 ppm of SO2 and 15% water vapor.

scholarly journals Carbon Dioxide Reforming of Methane over Ni Supported SiO2: Influence of the Preparation Method on the Resulting Structural Properties and Catalytic Activity

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 795 ◽  
Author(s):  
Hua-Ping Ren ◽  
Shao-Peng Tian ◽  
Si-Yi Ding ◽  
Gui-Qiu Huang ◽  
Min Zhu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Particle Size ◽  
Catalytic Activity ◽  
Citric Acid ◽  
Preparation Method ◽  
Complexing Agents ◽  
Impregnation Method ◽  
Carbon Dioxide Reforming ◽  
Highly Active ◽  
Before And After

Ni-C/SiO2 and Ni-G/SiO2 catalysts were prepared by a complexed-impregnation method using citric acid and glycine as complexing agents, respectively. Ni/SiO2 was also prepared by the conventional incipient impregnation method. All the catalysts were comparatively tested for carbon dioxide reforming of methane (CDR) at P = 1.0 atm, T = 750 °C, CO2/CH4 = 1.0, and GHSV = 60,000 mL·g−1·h−1. The results showed that Ni-C/SiO2 and Ni-G/SiO2 exhibited better CDR performance, especially regarding stability, than Ni/SiO2. The conversions of CH4 and CO2 were kept constant above 82% and 87% after 20 h of reaction over Ni-C/SiO2 and Ni-G/SiO2 while they were decreased from 81% and 88% to 56% and 59%, respectively, over the Ni/SiO2. The characterization results of the catalysts before and after the reaction showed that the particle size and the distribution of Ni, as well as the interactions between Ni and the support were significantly influenced by the preparation method. As a result, an excellent resistance to the coking deposition and the anti-sintering of Ni was obtained over the Ni-C/SiO2 and Ni-G/SiO2, leading to a highly active and stable CDR performance.

Preparation of Nanosized Pt-Au Alloy Catalyst and Its Activity in Methanol Oxidation

2007 ◽  
Vol 7 (11) ◽  
pp. 4073-4076 ◽  
Author(s):  
Ki-Joong Kim ◽  
Yong-Hwa Kim ◽  
Woon-Jo Jeong ◽  
Seung-Won Jeong ◽  
Jong-Che Park ◽  
...  
Keyword(s):  
Particle Size ◽  
Catalytic Activity ◽  
Methanol Oxidation ◽  
Flow Reactor ◽  
Metal Catalyst ◽  
Deposition Method ◽  
Oxidation Activity ◽  
Preparation Methods ◽  
Oxidation Of Methanol ◽  
Alloy Catalyst

The alloy catalyst has been widely used because it will be able to improve the activity and selectivity of the single metal catalyst in a given chemical reaction. In this study, the preparation and characteristics of nanosized Pt and Au particles on alumina and their catalytic activity were described. Nanosized Pt–Au catalysts were prepared by impregnation (IMP) method and deposition (DP) method using alumina or ZnO/Al2O3 as support. The size of Pt and Au particles were observed by transmission electron microscopy (TEM), energy dispersive spectroscope (EDS), and X-ray diffraction (XRD). Catalytic activity for oxidation of methanol was measured using a flow reactor. It could be seen that the Pt particle size and dispersion in the alloy catalysts was rarely influenced by preparation methods and Au particles coated by deposition method were well dispersed. TEM images showed that Au particles were well dispersed in the Pt/Au/ZnO/Al2O3 catalyst of which Au particles was supported by deposition method. The catalytic activity for methanol are given in the order of Pt-Au[IMP]/ZnO/Al2O3 > Pt[IMP]/Au[DP]/ZnO/Al2O3 > Au[DP]/Pt[IMP]/ZnO/Al2O3 > Pt-Au[DP]/ZnO/Al2O3. Therefore, Au particle size was doing not play an important role in increasing the oxidation activity, but the Au particles may promote the methanol oxidation.

Engineering surface defects and metal–support interactions on Pt/TiO2(B) nanobelts to boost the catalytic oxidation of CO

2018 ◽  
Vol 8 (19) ◽  
pp. 4934-4944 ◽  
Author(s):  
Jinghua Liu ◽  
Tong Ding ◽  
Hao Zhang ◽  
Guangcheng Li ◽  
Jinmeng Cai ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalytic Oxidation ◽  
Water Resistance ◽  
Surface Defects ◽  
High Catalytic Activity ◽  
Oxidation Of Co ◽  
Catalytic Oxidation Of Co ◽  
Metal Support ◽  
Metal Support Interactions

The thermally reduced Pt/TiO2(B) catalysts show high catalytic activity and good water resistance for the catalytic oxidation of CO.

Catalytic Oxidation of CO over Ag-Doped Manganese Oxide Catalysts: Preparation and Catalytic Activity

2015 ◽  
Vol 1089 ◽  
pp. 133-136 ◽  
Author(s):  
Zhi Dan Fu ◽  
Qing Ye ◽  
Shui Yuan Cheng ◽  
Dao Wang
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Manganese Oxide ◽  
Impregnation Method ◽  
Efficient Catalyst ◽  
Preparation Methods ◽  
Wet Impregnation ◽  
Adsorption Desorption ◽  
Wet Impregnation Method ◽  
Incorporation Method

The manganese oxide (MnO2) sample was synthesized by the reaction of KMnO4 with Mn (Ac)2 using the HNO3 solution as pH regulator. The Ag-doped manganese oxide, Ag/MnO2-Q and Ag/MnO2-H, were synthesized by incorporation method and typical wet impregnation method, respectively. The structure of catalysts was characterized by N2 adsorption/desorption and X-ray diffraction. The influences of preparation methods on the catalytic activity of CO oxidation were studied. The doping of Ag to MnO2 decreased the specific surface area of Ag/MnO2 catalysts, especially for Ag/MnO2-H samples prepared by traditional wet-impregnation method. The Ag/MnO2 catalysts showed higher catalytic activity for CO oxidation than that of MnO2. The catalytic activities of Ag/MnO2 samples strongly depended upon the preparing methods, among which 3Ag/MnO2-Q catalyst, prepared by the incorporation method, was the most efficient catalyst towards the addressed reactions. The excellent performance of 3Ag/MnO2-Q was mainly associated with the good low-temperature reducibility, abundant surface oxygen and broadly dispersed silver oxides species.

The DeNOx Characteristics of V/Ti Plate SCR Catalysts

2011 ◽  
Vol 356-360 ◽  
pp. 1712-1715
Author(s):  
Qiang Lu ◽  
Shu Hua Su ◽  
Shi Ye Fen ◽  
Wei Liang Cheng ◽  
Chang Qing Dong
Keyword(s):  
Nitric Oxide ◽  
Catalytic Activity ◽  
Selective Catalytic Reduction ◽  
Flue Gas ◽  
Catalytic Reduction ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Negative Effects ◽  
V2o5 Content ◽  
Scr Catalysts

A series of V2O5/WO3/TiO2plate catalysts were prepared via the incipient wetness impregnation method, with the V2O5content of 0.68 wt%, 1.01 wt%, 1.19 wt%, 1.5 wt% and the WO3loading of 4.8 wt%, 6.2 wt%, 7.9 wt%, 9.2 wt%, respectively. Selective catalytic reduction of nitric oxide by ammonia (NH3-SCR) experiments were performed to investigate the effects of the several factors on the performance of the catalysts, including the V2O5, WO3and MoO3content in the catalysts and the O2concentration in the flue gas. The results indicated that as the rising of the V2O5 content, the SCR activity of the V2O5/WO3/TiO2catalysts was firstly increased and then slightly decreased, with the best activity obtained at the V2O5content of 1.19 wt%. As the increasing of the WO3content, the activity was firstly increased slightly and then almost kept constant. Furthermore, the loading of the MoO3on the V2O5/WO3/TiO2plate catalysts would bring negative effects to the catalytic activity. In addition, the capability of the catalysts would slightly increase as the O2concentration rising up to 7%, and then became stable at higher O2concentrations.

Low-temperature catalytic oxidation of CO over highly active mesoporous Pd/CeO2–ZrO2–Al2O3catalyst

RSC Advances ◽  
2016 ◽  
Vol 6 (47) ◽  
pp. 41181-41188 ◽  
Author(s):  
Xin Liu ◽  
Ping Ning ◽  
Lisi Xu ◽  
Qixian Liu ◽  
Zhongxian Song ◽  
...  
Keyword(s):  
Particle Size ◽  
Catalytic Activity ◽  
Low Temperature ◽  
Catalytic Oxidation ◽  
Pore Volume ◽  
Oxidation Of Co ◽  
Highly Active ◽  
Catalytic Oxidation Of Co ◽  
P Addition

Addition of zirconium and aluminum into Pd/CeO2led to an increase of surface atomic ratios of Ce3+/Ce4+andOadsorbed/Olattice, pore volume, ratios and size of mesopores, catalytic activity, as well as decrease of particle size,EaandT100(60 °C).

scholarly journals Synthesis and Characterization of Metal Modified Catalysts for Decomposition of Ibuprofen from Aqueous Solutions

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 786 ◽  
Author(s):  
Soudabeh Saeid ◽  
Matilda Kråkström ◽  
Pasi Tolvanen ◽  
Narendra Kumar ◽  
Kari Eränen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Catalytic Activity ◽  
Liquid Chromatography ◽  
Metal Particle ◽  
Catalytic Ozonation ◽  
Preparation Methods ◽  
Metal Particle Size ◽  
Ozonation Process ◽  
By Products

The presence of pharmaceuticals in surface water, drinking water, and wastewater has attracted significant concern because of the non-biodegradability, resistance, and toxicity of pharmaceutical compounds. The catalytic ozonation of an anti-inflammatory pharmaceutical, ibuprofen was investigated in this work. The reaction mixture was analyzed and measured by high-performance liquid chromatography (HPLC). Liquid chromatography-mass spectrometry (LC-MS) was used for the quantification of by-products during the catalytic ozonation process. Ibuprofen was degraded by ozonation under optimized conditions within 1 h. However, some intermediate oxidation products were detected during the ibuprofen ozonation process that were more resistant than the parent compound. To optimize the process, nine heterogeneous catalysts were synthesized using different preparation methods and used with ozone to degrade the ibuprofen dissolved in aqueous solution. The aim of using several catalysts was to reveal the effect of various catalyst preparation methods on the degradation of ibuprofen as well as the formation and elimination of by-products. Furthermore, the goal was to reveal the influence of various support structures and different metals such as Pd-, Fe-, Ni-, metal particle size, and metal dispersion in ozone degradation. Most of the catalysts improved the elimination kinetics of the by-products. Among these catalysts, Cu-H-Beta-150-DP synthesized by the deposition–precipitation process showed the highest decomposition rate. The regenerated Cu-H-Beta-150-DP catalyst preserved the catalytic activity to that of the fresh catalyst. The catalyst characterization methods applied in this work included nitrogen adsorption–desorption, scanning electron microscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy. The large pore volume and small metal particle size contributed to the improved catalytic activity.

Preparation of Strong Acid Catalysts by Sulfate Treatment of Calcined Boehmite

1992 ◽  
Vol 57 (11) ◽  
pp. 2241-2247 ◽  
Author(s):  
Tomáš Hochmann ◽  
Karel Setínek
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Aluminum Sulfate ◽  
Solid Acid ◽  
Strong Acid ◽  
Acid Strength ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Preparation Methods ◽  
Indicator Method

Solid acid catalysts with acid strength of -14.52 < H0 < -8.2 were prepared by sulfate treatment of the samples of boehmite calcined at 105-800 °C. Two preparation methods were used: impregnation of the calcined boehmite with 3.5 M H2SO4 or mixing of the boehmite samples with anhydrous aluminum sulfate, in both cases followed by calcination in nitrogen at 650 °C. The catalysts were characterized by measurements of surface area, adsorption of pyridine and benzene, acid strength measurements by the indicator method and by catalytic activity tests in the isomerization of cyclohexene, p-xylene and n-hexane. Properties of the catalysts prepared by both methods were comparable.

scholarly journals Waste Animal Bones as Catalysts for Biodiesel Production; A Mini Review

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 630
Author(s):  
Fayaz Hussain ◽  
Saad Alshahrani ◽  
Muhammad Mujtaba Abbas ◽  
Haris Mahmood Khan ◽  
Asif Jamil ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Heterogeneous Catalyst ◽  
Recent Literature ◽  
Catalyst Preparation ◽  
Biodiesel Production ◽  
Waste Generation ◽  
Preparation Methods ◽  
Eu Legislation ◽  
Animal Bones ◽  
Disposal Cost

Slaughterhouse waste is considered to be an emerging issue because of its disposal cost. As an alternative, it would be a great prospect for the bioeconomy society to explore new usages of these leftover materials. As per food safety rules mentioned by EU legislation, all bone waste generated by slaughterhouses ought to be disposed of by rendering. The huge quantity of worldwide bone waste generation (130 billion kilograms per annum) is an environmental burden if not properly managed. The waste animal bones can be efficiently employed as a heterogeneous catalyst to produce biodiesel. This mini review summarized the recent literature reported for biodiesel generation using waste animal bones derived heterogeneous catalyst. It discusses the sources of bone waste, catalyst preparation methods, particularly calcination and its effects, and important characteristics of bones derived catalyst. It suggests that catalysts extracted from waste animal bones have suitable catalytic activity in transesterification of different oil sources to generate a good quality biodiesel.

scholarly journals A Thermally Conductive Pt/AAO Catalyst for Hydrogen Passive Autocatalytic Recombination

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 491
Author(s):  
Alina E. Kozhukhova ◽  
Stephanus P. du Preez ◽  
Aleksander A. Malakhov ◽  
Dmitri G. Bessarabov
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Combustion Temperature ◽  
Volume Fraction ◽  
Morphological Characteristics ◽  
Al Alloy ◽  
Impregnation Method ◽  
Case Scenario ◽  
Worst Case ◽  
Thermal Distribution

In this study, a Pt/anodized aluminum oxide (AAO) catalyst was prepared by the anodization of an Al alloy (Al6082, 97.5% Al), followed by the incorporation of Pt via an incipient wet impregnation method. Then, the Pt/AAO catalyst was evaluated for autocatalytic hydrogen recombination. The Pt/AAO catalyst’s morphological characteristics were determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The average Pt particle size was determined to be 3.0 ± 0.6 nm. This Pt/AAO catalyst was tested for the combustion of lean hydrogen (0.5–4 vol% H2 in the air) in a recombiner section testing station. The thermal distribution throughout the catalytic surface was investigated at 3 vol% hydrogen (H2) using an infrared camera. The Al/AAO system had a high thermal conductivity, which prevents the formation of hotspots (areas where localized surface temperature is higher than an average temperature across the entire catalyst surface). In turn, the Pt stability was enhanced during catalytic hydrogen combustion (CHC). A temperature gradient over 70 mm of the Pt/AAO catalyst was 23 °C and 42 °C for catalysts with uniform and nonuniform (worst-case scenario) Pt distributions. The commercial computational fluid dynamics (CFD) code STAR-CCM+ was used to compare the experimentally observed and numerically simulated thermal distribution of the Pt/AAO catalyst. The effect of the initial H2 volume fraction on the combustion temperature and conversion of H2 was investigated. The activation energy for CHC on the Pt/AAO catalyst was 19.2 kJ/mol. Prolonged CHC was performed to assess the durability (reactive metal stability and catalytic activity) of the Pt/AAO catalyst. A stable combustion temperature of 162.8 ± 8.0 °C was maintained over 530 h of CHC. To confirm that Pt aggregation was avoided, the Pt particle size and distribution were determined by TEM before and after prolonged CHC.

Sign in / Sign up

Export Citation Format

Share Document