A-site deficient perovskite: the parent for in situ exsolution of highly active, regenerable nano-particles as SOFC anodes

2015 ◽  
Vol 3 (20) ◽  
pp. 11048-11056 ◽  
Author(s):  
Yifei Sun ◽  
Jianhui Li ◽  
Yimin Zeng ◽  
Babak Shalchi Amirkhiz ◽  
Mengni Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Oxygen Vacancies ◽  
Electronic Conductivity ◽  
Nano Particles ◽  
Highly Active ◽  
A Site ◽  
Mobile Oxygen

Introduction of A-site deficiency on Ni-doped LaSrCrO3 anodes helps form highly mobile oxygen vacancies and remarkably enhances Ni nanoparticle reducibility, and significantly increases electronic conductivity and catalytic activity.

scholarly journals Correction: A-site deficient perovskite: the parent for in situ exsolution of highly active, regenerable nano-particles as SOFC anodes

2017 ◽  
Vol 5 (2) ◽  
pp. 852-853 ◽  
Author(s):  
Yifei Sun ◽  
Jianhui Li ◽  
Yimin Zeng ◽  
Babak Shalchi Amirkhiz ◽  
Mengni Wang ◽  
...  
Keyword(s):  
Nano Particles ◽  
Highly Active ◽  
A Site

Correction for ‘A-site deficient perovskite: the parent for in situ exsolution of highly active, regenerable nano-particles as SOFC anodes’ by Yifei Sun et al., J. Mater. Chem. A, 2015, 3, 11048–11056.

scholarly journals Highly Dispersed Pd Species Supported on CeO2 Catalyst for Lean Methane Combustion: The Effect of the Occurrence State of Surface Pd Species on the Catalytic Activity

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 772
Author(s):  
Yanxiong Liu ◽  
Changhua Hu ◽  
Longchun Bian
Keyword(s):  
Catalytic Activity ◽  
Oxygen Vacancies ◽  
Methane Combustion ◽  
Pd Nanoparticles ◽  
High Concentration ◽  
Ch4 Combustion ◽  
Highly Active ◽  
Δ Phase ◽  
Occurrence State ◽  
Comprehensive Characterization

The correlation between the occurrence state of surface Pd species of Pd/CeO2 for lean CH4 combustion is investigated. Herein, by using a reduction-deposition method, we have synthesized a highly active 0.5% PdO/CeO2-RE catalyst, in which the Pd nanoparticles are evenly dispersed on the CeO2 nanorods CeO2-R. Based on comprehensive characterization, we have revealed that the uniformly dispersed Pd nanoparticles with a particle size distribution of 2.3 ± 0.6 nm are responsible for the generation of PdO and PdxCe1−xO2−δ phase with –Pd2+–O2−–Ce4+– linkage, which can easily provide oxygen vacancies and facilitate the transfer of reactive oxygen species between the CeO2-R and Pd species. As a consequence, the remarkable catalytic activity of 0.5% Pd/CeO2-RE is related to the high concentration of PdO species on the surface of the catalyst and the synergistic interaction between the Pd species and the CeO2 nanorod.

Enhanced catalytic activity of oxygenated VOC deep oxidation on highly active in-situ generated GdMn2O5/GdMnO3 catalysts

2020 ◽  
Vol 578 ◽  
pp. 229-241 ◽  
Author(s):  
Mingming Guo ◽  
Kan Li ◽  
Hongbo Zhang ◽  
Xin Min ◽  
Xiaofang Hu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Deep Oxidation ◽  
Highly Active

In situ synthesized Au–Ag nanocages on graphene oxide nanosheets: a highly active and recyclable catalyst for the reduction of 4-nitrophenol

2016 ◽  
Vol 40 (2) ◽  
pp. 1685-1692 ◽  
Author(s):  
Min Hong ◽  
Lidan Xu ◽  
Fangli Wang ◽  
Shuling Xu ◽  
Haibo Li ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Catalytic Activity ◽  
Induction Time ◽  
Recyclable Catalyst ◽  
Good Stability ◽  
High Catalytic Activity ◽  
Graphene Oxide Nanosheets ◽  
Highly Active

Graphene oxide-supported hollow Au–Ag alloy nanocages were synthesized here, which exhibited short induction time, high catalytic activity and good stability against agglomeration for the reduction of 4-nitrophenol to 4-aminophenol.

scholarly journals In Situ Wet Etching of MoS2@dWO3 Heterostructure as Ultra-Stable Highly Active Electrocatalyst for Hydrogen Evolution Reaction

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 977
Author(s):  
Xintian Liu ◽  
Congwei Wang
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Oxygen Vacancies ◽  
Rapid Development ◽  
Strong Stability ◽  
Wet Etching ◽  
Two Dimensional ◽  
Highly Active ◽  
Anisotropic Substrate

Electrocatalysts featuring robust structure, excellent catalytic activity and strong stability are highly desirable, but challenging. The rapid development of two-dimensional transition metal chalcogenide (such as WO3, MoS2 and WS2) nanostructures offers a hopeful strategy to increase the active edge sites and expedite the efficiency of electronic transport for hydrogen evolution reaction. Herein, we report a distinctive strategy to construct two-dimensional MoS2@dWO3 heterostructure nanosheets by in situ wet etching. Synthesized oxygen-incorporated MoS2-was loaded on the surface of defective WO3 square nanoframes with abundant oxygen vacancies. The resulting nanocomposite exhibits a low overpotential of 191 mV at 10 mA cm−2 and a very low Tafel slope of 42 mV dec−1 toward hydrogen evolution reaction. The long-term cyclic voltammetry cycling of 5000 cycles and more than 80,000 s chronoamperometry tests promises its outstanding stability. The intimate and large interfacial contact between MoS2 and WO3, favoring the charge transfer and electron–hole separation by the synergy of defective WO3 and oxygen-incorporated MoS2, is believed the decisive factor for improving the electrocatalytic efficiency of the nanocomposite. Moreover, the defective WO3 nanoframes with plentiful oxygen vacancies could serve as an anisotropic substrate to promote charge transport and oxygen incorporation into the interface of MoS2. This work provides a unique methodology for designing and constructing excellently heterostructure electrocatalysts for hydrogen evolution reaction.

Ba-Addition Induced Enhanced Surface Reducibility of SrTiO3: Implication on Catalytic Aspects

2019 ◽  
Author(s):  
Noopur Jain ◽  
ahin roy ◽  
Angana De
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Oxygen Vacancies ◽  
Cation Substitution ◽  
Surface Oxygen ◽  
Chemical States ◽  
A Site ◽  
Adsorption Desorption ◽  
Enhanced Surface

This work compares the capacity of generating the surface oxygen vacancies over SrTiO<sub>3</sub>, BaTiO<sub>3</sub> and the mixed Sr<sub>0.5</sub>Ba<sub>0.5</sub>TiO<sub>3</sub>. This aspect is elucidated by significantly different chemical states of the elements on the surface of the three materials. Along with the fundamental materials aspect, CO oxidation studies complement the highest surface reducibility of the Sr<sub>0.5</sub>Ba<sub>0.5</sub>TiO<sub>3</sub> catalyst. With detailed adsorption-desorption studies, we report that the A-site cation substitution renders a better surface-reducibility induced catalytic activity for CO oxidation.

Ba-Addition Induced Enhanced Surface Reducibility of SrTiO3: Implication on Catalytic Aspects

2019 ◽  
Author(s):  
Noopur Jain ◽  
ahin roy ◽  
Angana De
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Oxygen Vacancies ◽  
Cation Substitution ◽  
Surface Oxygen ◽  
Chemical States ◽  
A Site ◽  
Adsorption Desorption ◽  
Enhanced Surface

This work compares the capacity of generating the surface oxygen vacancies over SrTiO<sub>3</sub>, BaTiO<sub>3</sub> and the mixed Sr<sub>0.5</sub>Ba<sub>0.5</sub>TiO<sub>3</sub>. This aspect is elucidated by significantly different chemical states of the elements on the surface of the three materials. Along with the fundamental materials aspect, CO oxidation studies complement the highest surface reducibility of the Sr<sub>0.5</sub>Ba<sub>0.5</sub>TiO<sub>3</sub> catalyst. With detailed adsorption-desorption studies, we report that the A-site cation substitution renders a better surface-reducibility induced catalytic activity for CO oxidation.

Octahedral Layered Birnessite (OL) Supported Ag Catalysts: Characterization and Catalytic Oxidation of CO

2020 ◽  
Vol 304 ◽  
pp. 35-44
Author(s):  
Meng Yue Chen ◽  
Ning Dong ◽  
Qing Ye ◽  
Zhi Dan Fu
Keyword(s):  
Catalytic Activity ◽  
Oxygen Vacancies ◽  
Catalyst Surface ◽  
Oxygen Free Radical ◽  
Oxidation Of Co ◽  
Exchange Method ◽  
In Situ Drifts ◽  
Redox Method ◽  
Ag Catalysts

Octahedral layered birnessite (OL) was synthesized by redox method, and OL supported Ag catalysts (xAg/OL, x = 0.1wt%, 0.2wt%, 0.3wt%, 0.5wt%) were prepared by ion exchange method. Then catalysts were characterized by XRD, SEM, BET, H2-TPR, TG, O2-TPD and in-situ DRIFTS, while the catalytic activity of CO was evaluated. Among xAg/OL samples, the 0.3Ag/OL exhibited the best catalytic activity for CO oxidation (T50 = 105 oC and T90 = 135 oC). The results show that the chemical adsorption of oxygen, the low-temperature reducibility and the strong interaction between the Ag species and OL are related to the excellent catalytic activity of xAg/OL. The reaction mechanism was studied by in-situ DRIFTS. First, O2 was adsorbed and activated on the oxygen vacancies of xAg/OL, then formed oxygen free radical attacked the adsorbed CO and produced CO2, subsequently CO2 desorbed from the catalyst surface. Oxygen vacancies was supplemented by gas O2, thus circulating.

Characterization and Catalytic Reactivity of LaNi1-xMgxO3-δ Perovskite Oxides in Reforming of Methane with CO2 and O2

2017 ◽  
Vol 16 (4) ◽  
Author(s):  
Alireza Jahangiri ◽  
Majid Saidi ◽  
Abolfazl Mohammadi ◽  
Mehdi Sedighi
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Sol Gel ◽  
Synthesis Method ◽  
Sample Surface ◽  
Nano Particles ◽  
Partial Substitution ◽  
Syngas Production ◽  
Highly Active ◽  
Oxide Phases

Abstract A series of Mg doped LaNiO3 nano particles by solids denoted as LaNi1-xMgxO3-δ (x = 0, 0.1, 0.2, 0.4, 0.6, 0.8 and 1) were prepared by the modified citrate sol-gel method and investigated as catalysts for combine reforming of methane (CRM).The resulting oxides were examined by using XRD, BET, ICP, SEM, EDS, TEM, TPR and TGA techniques, under the condition of as-synthesized and used samples. The results showed that highly homogeneous and crystalline oxides with particle sizes in the range of nanometers were obtained through this synthesis method. The XRD patterns of the prepared LaNi1-xMgxO3-δsolids confirmed with increasing Mg amount not only perovskite structure could not form correctly but also the spinel (La2NiO4) and oxide phases (MgO and NiO) are produced on the sample surface. Also according to BET results, the presence of these oxide phases lead to the increase in the surface area of samples .Although, increasing in surface area had not a significant effect in results of activity tests. TPR analysis revealed that the reduction of the prepared samples became more difficult by increasing the degree of substitution (x). The effects of the partial substitution of Ni by Mg and reaction temperatures (600–800 °C) were investigated in CRM process, after reduction of the samples under hydrogen. Although, all catalysts, except LaMgO3, were found to be highly active toward the syngas production during the CRM process but substitution of Ni by Mg could not improve the catalytic activity of the LaNi1-xMgxO3-δ in this process. The catalytic activity in the steady state was found to decrease in the following order: $${\text{LaNi}}{{\text{O}}_{\text{3}}} \gt {\text{LaN}}{{\text{i}}_{{\text{0}}{\text{.4}}}}{\text{M}}{{\text{g}}_{{\text{0}}{\text{.6}}}}{{\text{O}}_{{\text{3 - }}\delta }} \gt {\text{LaN}}{{\text{i}}_{{\text{0}}{\text{.6}}}}{\text{M}}{{\text{g}}_{{\text{0}}{\text{.4}}}}{{\text{O}}_{{\text{3 - }}\delta }} \gt {\text{LaN}}{{\text{i}}_{{\text{0}}{\text{.9}}}}{\text{M}}{{\text{g}}_{{\text{0}}{\text{.1}}}}{{\text{O}}_{{\text{3 - }}\delta }} \gt {\text{LaN}}{{\text{i}}_{{\text{0}}{\text{.8}}}}{\text{M}}{{\text{g}}_{{\text{0}}{\text{.2}}}}{{\text{O}}_{{\text{3 - }}\delta }} \gt {\text{LaMgO3 - }}\delta$$ Of course, according to the TPR and TGA results, the stability of the samples increased and the coke deposits on the catalyst surface decreased with increasing of x, respectively.

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