scholarly journals Cold Plasma Preparation of Pd/Graphene Catalyst for Reduction of p-Nitrophenol

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1341
Author(s):  
Qian Zhao ◽  
Decai Bu ◽  
Zhihui Li ◽  
Xiuling Zhang ◽  
Lanbo Di
Keyword(s):  
Metal Nanoparticles ◽  
Cold Plasma ◽  
Heterogeneous Catalysts ◽  
Catalytic Reduction ◽  
Pd Nanoparticles ◽  
Atomic Ratio ◽  
Thermal Reduction ◽  
High Dispersion ◽  
Pd Catalysts ◽  
Metal Support Interaction

Supported metal nanoparticles with small size and high dispersion can improve the performance of heterogeneous catalysts. To prepare graphene-supported Pd catalysts, graphene and PdCl2 were used as support and Pd precursors, respectively. Pd/G-P and Pd/G-H catalysts were prepared by cold plasma and conventional thermal reduction, respectively, for the catalytic reduction of p-nitrophenol (4-NP). The reaction followed quasi-first-order kinetics, and the apparent rate constant of Pd/G-P and Pd/G-H was 0.0111 and 0.0042 s−1, respectively. The graphene support was exfoliated by thermal reduction and cold plasma, which benefits the 4-NP adsorption. Pd/G-P presented a higher performance because cold plasma promoted the migration of Pd species to the support outer surface. The Pd/C atomic ratio for Pd/G-P and Pd/G-H was 0.014 and 0.010, respectively. In addition, the Pd nanoparticles in Pd/G-P were smaller than those in Pd/G-H, which was beneficial for the catalytic reduction. The Pd/G-P sample presented abundant oxygen-containing functional groups, which anchored the metal nanoparticles and enhanced the metal-support interaction. This was further confirmed by the shift in the binding energy to a high value for Pd3d in Pd/G-P. The cold plasma method operated under atmospheric pressure is effective for the preparation of Pd/G catalysts with enhanced catalytic activity for 4-NP reduction.

Activity of yFe-10Cu/H-Sep and xCu/H-Sep for the Selective Catalytic Reduction of NO with Propylene

2012 ◽  
Vol 518-523 ◽  
pp. 281-284
Author(s):  
Qing Ye ◽  
Hai Ping Wang ◽  
Hai Xia Zhao ◽  
Shui Yuan Cheng ◽  
Tian Fang Kang
Keyword(s):  
Catalytic Reduction ◽  
Catalytic Performance ◽  
High Dispersion ◽  
High Catalytic Activity ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Promotional Effect ◽  
Scr Of No ◽  
Metal Support Interaction ◽  
Metal Support

Cu supported on acid-treated sepiolite catalysts (xCu/H-Sep, x = 0  20.0 wt%) or Cu-Fe mixed supported on acid-treated sepiolite catalysts (yFe-10Cu/H-Sep, y = 0  20.0 wt%) were prepared by the incipient wetness impregnation method. The xCu/H-Sep and yFe-10Cu/H-Sep catalysts were characterized by means of XRD, BET, XRF, XPS, and H2-TPR techniques, and their catalytic activities were evaluated for the SCR of NO with propylene. XPS and XRD results indicate that there was the co-presence of Cu+-Cu2+ and Fe2+-Fe3+ over the surfaces of yFe-10Cu/H-Sep catalysts, and there was a strong interaction between Cu, Fe and sepiolite. High promotional effect of iron additive on the catalytic performance of Cu/H-Sep catalyst were found in C3H6-SCR of NO reaction. The highest activity of 65% NO conversion was obtained over 15Fe-10Cu/H-Sep catalyst at 280 oC under the condition of 1000 ppm NO, 1000 ppm C3H6, and 5% O2. The high catalytic activity of 15Fe-10Cu/H-Sep catalyst for NO reduction was due to its high reducibility to activate C3H6 to selectively reduce NO in the presence of excess O2. The high dispersion of copper oxides and strong metal-support interaction over 15Fe-10Cu/H-Sep catalyst also improve its catalytic performance.

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 ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Atmospheric Pressure ◽  
Bimetallic Catalysts ◽  
High Performance ◽  
Cold Plasma ◽  
Low Cost ◽  
Catalytic Decomposition ◽  
High Dispersion ◽  
Metal Support Interaction ◽  
Barrier Discharge Plasma

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.

scholarly journals The Isocyanurate-Carbamate-Bridged Hybrid Mesoporous Organosilica: An Exceptional Anchor for Pd Nanoparticles and a Unique Catalyst for Nitroaromatics Reduction

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 621
Author(s):  
Ali Zebardasti ◽  
Mohammad G. Dekamin ◽  
Esmail Doustkhah
Keyword(s):  
Mesoporous Silica ◽  
Metal Nanoparticles ◽  
Noble Metal ◽  
Room Temperature ◽  
Heterogeneous Catalysts ◽  
Pd Nanoparticles ◽  
Noble Metal Nanoparticles ◽  
Green Catalyst ◽  
Mesoporous Organosilica ◽  
Mesoporous Organosilicas

Hybridisation of mesoporous organosilicas (MO) to reinforce the surface capability in adsorption and stabilisation of noble metal nanoparticles is of great attention in generating/supporting noble metal within their matrices and transforming them into efficient heterogeneous catalysts. Here, we used a unique hybrid of organic-inorganic mesoporous silica in which pore profile pattern was similar to the well-known mesoporous silica, SBA-15 for catalysis. This hybrid mesoporous organosilica was further engaged as a support in the synthesis and stabilisation of Pd nanoparticles on its surface, and then, the obtained Pd-supported MO was employed as a heterogeneous green catalyst in the conversion of aqueous p-nitrophenol (PNP) to p-aminophenol (PAP) at room temperature with efficient recyclability.

scholarly journals Boosting Hydrogen Production from Formic Acid over Pd Catalysts by Deposition of N-Containing Precursors on the Carbon Support

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3885 ◽  
Author(s):  
Golub ◽  
Beloshapkin ◽  
Gusel’nikov ◽  
Bolotov ◽  
Parmon ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Formic Acid ◽  
Carbon Support ◽  
Pd Nanoparticles ◽  
High Dispersion ◽  
Pd Catalysts ◽  
Strong Electron ◽  
High Hydrogen ◽  
Hydrogen Carrier ◽  
Pyridinic Nitrogen

Formic acid is a promising liquid organic hydrogen carrier (LOHC) since it has relatively high hydrogen content (4.4 wt%), low inflammability, low toxicity and can be obtained from biomass or from CO2. The aim of the present research was the creation of efficient 1 wt% Pd catalysts supported on mesoporous graphitic carbon (Sibunit) for the hydrogen production from gas-phase formic acid. For this purpose, the carbon support was modified by pyrolysis of deposited precursors containing pyridinic nitrogen such as melamine (Mel), 2,2′-bipyridine (Bpy) or 1,10-phenanthroline (Phen) at 673 K. The following activity trend of the catalysts Pd/Mel/C > Pd/C ~ Pd/Bpy/C > Pd/Phen/C was obtained. The activity of the Pd/Mel/C catalyst was by a factor of 4 higher than the activity of the Pd/C catalyst at about 373 K and the apparent activation energy was significantly lower than those for the other catalysts (32 vs. 42–46 kJ/mol). The high activity of the melamine-based samples was explained by a high dispersion of Pd nanoparticles (~2 nm, HRTEM) and their strong electron-deficient character (XPS) provided by interaction of Pd with pyridinic nitrogen species of the support. The presented results can be used for the development of supported Pd catalysts for hydrogen production from different liquid organic hydrogen carriers.

scholarly journals Facile Redox Synthesis of Novel Bimetallic Crn+/Pd0 Nanoparticles Supported on SiO2 and TiO2 for Catalytic Selective Hydrogenation with Molecular Hydrogen

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 583
Author(s):  
Olga A. Kirichenko ◽  
Elena A. Redina ◽  
Gennady I. Kapustin ◽  
Marina S. Chernova ◽  
Anastasiya A. Shesterkina ◽  
...  
Keyword(s):  
Selective Hydrogenation ◽  
Photoelectron Spectroscopy ◽  
Catalytic Reduction ◽  
Pd Nanoparticles ◽  
Nanoparticle Size ◽  
Ambient Conditions ◽  
Pd Catalysts ◽  
Adsorbed Co ◽  
Temperature Programmed ◽  
Redox Method

The bimetallic Crn+/Pd0 nanoparticles have been synthesized for the first time by a two-step redox method. The method includes the deposition of Pd0 nanoparticles on the surface of SiO2 and TiO2 carriers followed by the deposition of Crn+ on the surface of Pd0 nanoparticles using the redox procedures, which are based on the catalytic reduction of Crn+ with H2 in aqueous suspensions at ambient conditions. Transmission (TEM) and scanning (SEM) electron microscopy, X-ray photoelectron spectroscopy (XPS), Fourie-transformed infrared spectroscopy of adsorbed CO (FTIR-CO), and CO chemisorption studies were performed to characterize the morphology, nanoparticle size, element, and particle distribution, as well as the electronic state of deposited metals in the obtained catalysts. A decrease in nanoparticle size from 22 nm (Pd/SiO2) to 2–6 nm (Pd/TiO2) makes possible deposition of up to 1.1 wt.% Cr most likely as Cr3+. The deposition of CrOx species on the surface of Pd nanoparticles was confirmed using FTIR of adsorbed CO and the method of temperature-programmed reduction with hydrogen (TPR-H2). The intensive hydrogen consumption in the temperature ranges from −50 °C to 40 °C (Cr/Pd/SiO2) and from −90 °C to −40 °C (Cr/Pd/TiO2) was first observed for the supported Pd catalysts. The decrease in the temperature of β-PdHx decomposition indicates the strong interaction between the deposited Crn+ species and Pd0 nanoparticle after reduction with H2 at 500 °C. The novel Crn+/Pd/TiO2 catalysts demonstrated a considerably higher activity in selective hydrogenation of phenylacetylene than the Pd/TiO2 catalyst at ambient conditions.

scholarly journals Biotechnological synthesis of Pd-based nanoparticle catalysts

2022 ◽  
Author(s):  
Christopher Egan-Morriss ◽  
Richard L. Kimber ◽  
Nigel A. Powell ◽  
Jonathan R. Lloyd
Keyword(s):  
Metal Nanoparticles ◽  
Heterogeneous Catalysts ◽  
Pd Nanoparticles ◽  
Coupling Reactions ◽  
Nanoparticle Catalysts ◽  
Supported Pd

Cell supported Pd metal nanoparticles are sustainably synthesised via microbial bioreduction. Bio-Pd nanoparticles are effective heterogeneous catalysts that catalyse industrially important reactions, such as hydrogenation and C–C coupling reactions.

Metal nanoparticles supported on two-dimensional graphenes as heterogeneous catalysts

2016 ◽  
Vol 312 ◽  
pp. 99-148 ◽  
Author(s):  
Sergio Navalon ◽  
Amarajothi Dhakshinamoorthy ◽  
Mercedes Alvaro ◽  
Hermenegildo Garcia
Keyword(s):  
Metal Nanoparticles ◽  
Heterogeneous Catalysts ◽  
Two Dimensional

A facile approach to fabricate halloysite/metal nanocomposites with preformed and in situ synthesized metal nanoparticles: a comparative study of their enhanced catalytic activity

2015 ◽  
Vol 44 (19) ◽  
pp. 8906-8916 ◽  
Author(s):  
Sankar Das ◽  
Subhra Jana
Keyword(s):  
Catalytic Activity ◽  
Comparative Study ◽  
Metal Nanoparticles ◽  
Heterogeneous Catalysts ◽  
Cost Effective ◽  
Environmentally Benign ◽  
Metal Nanocomposites

Halloysite/metal nanocomposites have been synthesized through the immobilization of preformed and in situ synthesized metal nanoparticles over halloysite surfaces, which in turn produce efficient, cost-effective, and environmentally benign heterogeneous catalysts.

scholarly journals The Multifunctional Roles of Chitosan in the Formation of Flower-Shaped Palladium Nanoparticles

2021 ◽  
Vol 3 (1) ◽  
pp. 18
Author(s):  
Thi Tuong Vy Phan
Keyword(s):  
Green Synthesis ◽  
Metal Nanoparticles ◽  
Human Health ◽  
Palladium Nanoparticles ◽  
Pd Nanoparticles ◽  
The Novel ◽  
Natural Polymers ◽  
Green Method ◽  
Harmful Effects

The chemical and physical routes are usually used to synthesize metal nanoparticles. However, the harmful effects on the environment and human health has turned scientists into finding greener methods. We have developed the novel green method for the synthesis of flower Pd nanoparticles based on the chitosan (CS) polymer. In this method, CS can work as a stabilizer, a shape-directing agent, and a size-controllable agent for the synthesis of these nanoparticles. This study provides pioneer evidence about the multifunctional roles of natural polymers in the preparation of metal nanoparticles. Deep and extensive studies should be conducted to explore the great benefits of natural polymers in the green synthesis of metal nanoparticles.

scholarly journals A brief review on the reaction mechanisms of CO2 hydrogenation into methanol

2020 ◽  
Vol 3 (2) ◽  
pp. 33-40
Author(s):  
Jawed Qaderi
Keyword(s):  
Catalytic Hydrogenation ◽  
Density Functional ◽  
Heterogeneous Catalysts ◽  
Catalytic Reduction ◽  
Kinetic Monte Carlo ◽  
Low Cost ◽  
Hydrogenation Of Co2 ◽  
Fuel Prices ◽  
Metal Metal ◽  
Reduction Of Co2

The catalytic reduction of CO2 to methanol is an appealing option to reduce greenhouse gas concentration as well as renewable energy production. In addition, the exhaustion of fossil fuel, increase in earth temperature and sharp increases in fuel prices are the main driving factor for exploring the synthesis of methanol by hydrogenating CO2. Many studies on the catalytic hydrogenation of CO2 to methanol were published in the literature over the last few decades. Many of the studies have presented different catalysts having high stability, higher performance, low cost, and are immediately required to promote conversion. Understanding the mechanisms involved in the conversion of CO2 is essential as the first step towards creating these catalysts. This review briefly summarizes recent theoretical developments in mechanistic studies focused on using density functional theory, kinetic Monte Carlo simulations, and microkinetics modeling. Based on these simulation techniques on different transition metals, metal/metal oxide, and other heterogeneous catalysts surfaces, mainly, three important mechanisms that have been recommended are the formate (HCOO), reverse water–gas shift (RWGS), and trans-COOH mechanisms. Recent experimental and theoretical efforts appear to demonstrate that the formate route in which the main intermediate species is H2CO* in the reaction route, is more favorable in catalytic hydrogenation of CO2 to chemical fuels in various temperature and pressure conditions.

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