scholarly journals Effects of Pd on Catalysis by Au: CO Adsorption, CO Oxidation, and Cyclohexene Hydrogenation by Supported Au and Pd–Au Catalysts

ACS Catalysis ◽  
2013 ◽  
Vol 3 (11) ◽  
pp. 2644-2653 ◽  
Author(s):  
Timothy Ward ◽  
Laurent Delannoy ◽  
Ruth Hahn ◽  
Shane Kendell ◽  
Christopher J. Pursell ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Co Adsorption ◽  
Cyclohexene Hydrogenation

scholarly journals Unique structure of active platinum-bismuth site for oxidation of carbon monoxide

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bing Nan ◽  
Qiang Fu ◽  
Jing Yu ◽  
Miao Shu ◽  
Lu-Lu Zhou ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Low Temperature ◽  
Co Oxidation ◽  
Density Functional ◽  
Technology Development ◽  
Co Adsorption ◽  
Combustion Engines ◽  
Advanced Combustion ◽  
Surface Metal ◽  
Bismuth Cluster

AbstractAs the technology development, the future advanced combustion engines must be designed to perform at a low temperature. Thus, it is a great challenge to synthesize high active and stable catalysts to resolve exhaust below 100 °C. Here, we report that bismuth as a dopant is added to form platinum-bismuth cluster on silica for CO oxidation. The highly reducible oxygen species provided by surface metal-oxide (M-O) interface could be activated by CO at low temperature (~50 °C) with a high CO2 production rate of 487 μmolCO2·gPt−1·s−1 at 110 °C. Experiment data combined with density functional calculation (DFT) results demonstrate that Pt cluster with surface Pt−O−Bi structure is the active site for CO oxidation via providing moderate CO adsorption and activating CO molecules with electron transformation between platinum atom and carbon monoxide. These findings provide a unique and general approach towards design of potential excellent performance catalysts for redox reaction.

Atomically dispersed Au catalysts supported on CeO2 foam: controllable synthesis and CO oxidation reaction mechanism

Nanoscale ◽  
2017 ◽  
Vol 9 (43) ◽  
pp. 16817-16825 ◽  
Author(s):  
Hao Wang ◽  
Jianhua Shen ◽  
Jianfei Huang ◽  
Tengjing Xu ◽  
Jingrun Zhu ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Co Oxidation ◽  
Oxidation Reaction ◽  
Co Adsorption ◽  
Controllable Synthesis ◽  
Co Oxidation Reaction

The Au atoms on CeO2 foam are a more stable site for CO adsorption on the catalysts.

scholarly journals CO oxidation over Pt-modified CuO catalysts in the presence of water vapour and SO2

2015 ◽  
Vol 18 (2) ◽  
pp. 187-196
Author(s):  
Tri Nguyen ◽  
Anh Cam Ha ◽  
Loc Cam Luu ◽  
Cuong Tien Hoang ◽  
Thi Thi Yen Trinh ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Water Vapour ◽  
Co Adsorption ◽  
X Ray Diffraction ◽  
Active Centers ◽  
Highly Active ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Adsorption Of Co ◽  
Temperature Programmed

The optimal Pt-modified CuO supported on γ-Al2O3 and γ-Al2O3 + CeO2 catalysts have been prepared. Physico-chemical characteristics of catalysts were investigated and determined by the methods of N2 adsorption (BET), X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), temperature-programmed reduction (TPR), and hydrogen pulse chemisorption (HPC). The characteristics of carbon monoxide (CO) adsorption on catalysts were defined by the method of infrared spectroscopy (IR) in the range of 4000 – 400 cm-1. The effect of the mixture of water vapour and SO2 on the activity of these catalysts for the CO oxidation was assessed. Reactions were conducted at 200oC and 350oC in the absence and presence of the mixture of water vapour (1.1 mol %) and SO2 (0.0625 mol %). Concentrations of O2 and CO in the gas mixture were 9.2 mol % and 0.5 mol %, respectively. The results showed that in the catalysts there exist highly active centers Cu1+ and Pt2+. On the catalysts the adsorption of CO on Cu2+, Pt2+, CeO2, and γ - Al2O3 centres was observed. Addition of CeO2 led to increase the reductivity, CO adsorption but decrease in specific surface area of catalyst. The result PtCu/CeAl catalyst shown higher active, but lower stability compared to PtCu/Al catalyst. The mixture of water vapour and SO2 showed the reversible poisoning toward the Pt-CuO catalysts at a temperature of 350oC, but irreversible at 200oC

scholarly journals Catalytic Behaviour of Flame-Made CuO-CeO2 Nanocatalysts in Efficient CO Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 256 ◽  
Author(s):  
Feng Zhao ◽  
Shuangde Li ◽  
Xiaofeng Wu ◽  
Renliang Yue ◽  
Weiman Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Co Oxidation ◽  
Photoelectron Spectroscopy ◽  
Co Adsorption ◽  
Synergistic Interaction ◽  
Flame Spray ◽  
Oxidation Activity ◽  
X Ray

CuO-CeO2 nanocatalysts with varying CuO contents (1, 5, 9, 14 and 17 wt %) were prepared by one-step flame spray pyrolysis (FSP) and applied to CO oxidation. The influences of CuO content on the as-prepared catalysts were systematically characterized by X-ray diffraction (XRD), N2 adsorption-desorption at −196 °C, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and hydrogen-temperature programmed reduction (H2-TPR). A superior CO oxidation activity was observed for the 14 wt % CuO-CeO2 catalyst, with 90% CO conversion at 98 °C at space velocity (60,000 mL × g−1 × h−1), which was attributed to abundant surface defects (lattice distortion, Ce3+, and oxygen vacancies) and high reducibility supported by strong synergistic interaction. In addition, the catalyst also displayed excellent stability and resistance to water vapor. Significantly, in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) showed that in the CO catalytic oxidation process, the strong synergistic interaction led readily to dehydroxylation and CO adsorption on Cu+ at low temperature. Furthermore, in the feed of water vapor, although there was an adverse effect on the access of CO adsorption, there was also a positive effect on the formation of fewer carbon intermediates. All these results showed the potential of highly active and water vapor-resistive CuO-CeO2 catalysts prepared by FSP.

First-principles Study of PdAu Segregation with CO Coverage

2009 ◽  
Vol 1177 ◽  
Author(s):  
Bin Shan ◽  
Jangsuk Hyun ◽  
Neeti Kapur ◽  
Kyeongjae Cho
Keyword(s):  
Diesel Engine ◽  
Co Oxidation ◽  
First Principles ◽  
Surface Composition ◽  
Co Adsorption ◽  
Quantitative Relationship ◽  
Pure Metal ◽  
Oxidation Catalyst ◽  
Embedded Atom ◽  
Key Factor

AbstractAlloying has been one of the strategies to develop alternatives to Pt based CO oxidation catalyst. PdAu bimetallic alloy has recently been shown to have better reactivity and thermal stability toward CO oxidation for diesel engine applications as compared to pure metal catalysts. The key factor for low temperature light off in diesel engine catalysis is reactivity of alloy catalysts under CO environment, which in turn depends on the alloy surface composition and morphology. We explored the segregation processes in bimetallic Pd-Au alloy using first-principles calculations, assisted by a Monte-Carlo (MC) scheme that combines an improved Embedded Atom Method (EAM) and an atomistic treatment for adsorbed CO molecules for searching low energy states. Our simulation results show that PdAu surface changes from Au-rich to Pd-rich with increase in CO coverage up to 0.75 ML, beyond which additional CO adsorption is no longer favorable. A quantitative relationship between CO coverage and Pd concentrations on the surface is also revealed.

scholarly journals Novel structure of active platinum-bismuth site for oxidation of carbon monoxide

2020 ◽  
Author(s):  
Bing Nan ◽  
Qiang Fu ◽  
Miao Shu ◽  
Lulu Zhou ◽  
Wei-Wei Wang ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Low Temperature ◽  
Co Oxidation ◽  
Density Functional ◽  
Technology Development ◽  
Co Adsorption ◽  
Advanced Combustion ◽  
Novel Structure ◽  
Surface Metal ◽  
Bismuth Cluster

Abstract As the technology development, the future advanced combustion engines must be designed to perform at a low temperature. Thus, it is a great challenge to synthesize high active and stable catalysts to resolve exhaust below 100 °C. Here, we report that bismuth as a dopant added to form platinum-bismuth cluster on silica for CO oxidation. The highly reducible oxygen species provided by surface metal-oxide (M-O) interface could be activated by CO at low temperature (~ 50 °C) with a high CO2 production rate of 487 µmolCO2·gPt−1·s− 1 at 110 °C. Experiment data combined with density functional calculation (DFT) results demonstrate that Pt cluster with surface Pt−O−Bi structure is the active site for CO oxidation via providing moderate CO adsorption and activating CO molecules with electron transformation between platinum atom and carbon monoxide. These findings provide a novel and general approach towards design of potential outstanding performance catalysts for redox reaction.

scholarly journals Frontispiece: A CO Adsorption Site Change Induced by Copper Substitution in a Ruthenium Catalyst for Enhanced CO Oxidation Activity

2019 ◽  
Vol 58 (8) ◽  
Author(s):  
Bo Huang ◽  
Hirokazu Kobayashi ◽  
Tomokazu Yamamoto ◽  
Takaaki Toriyama ◽  
Syo Matsumura ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Co Adsorption ◽  
Ruthenium Catalyst ◽  
Adsorption Site ◽  
Oxidation Activity ◽  
Site Change ◽  
Copper Substitution

First-principle study of CO adsorption and oxidation on Sm-doped CeO2(111) surface

RSC Advances ◽  
2016 ◽  
Vol 6 (24) ◽  
pp. 20349-20356 ◽  
Author(s):  
Tao Xie ◽  
Xu-Dong Wang ◽  
Man Yao ◽  
Xiong-Shan Liu ◽  
Yong-Gang Chen
Keyword(s):  
Co Oxidation ◽  
Surface Properties ◽  
Co Adsorption ◽  
Catalytic Performance ◽  
First Principle ◽  
Doped Ceo2

The surface properties and CO oxidation on Sm doped CeO2(111) have been studied systematically by using the DFT+U method to reveal the influence of Sm on the catalytic performance of CeO2(111).

CO adsorption and CO oxidation on Rh(100)

1996 ◽  
Vol 99 (1) ◽  
pp. 1-8 ◽  
Author(s):  
A. Baraldi ◽  
L. Gregoratti ◽  
G. Comelli ◽  
V.R. Dhanak ◽  
M. Kiskinova ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Co Adsorption
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