Influence of CO on the Activation, O-Vacancy Formation, and Performance of Au/ZnO Catalysts in CO2 Hydrogenation to Methanol

Zirconium doping dramatically facilitates O vacancy formation in ceria nanoparticles not only at the surface but also in four-coordinated inner O positions, which enhances O mobility. In mixed nanoparticles zirconium tends to occupy inner sites.

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Synthesis of DME by CO2 hydrogenation over La2O3-modified CuO-ZnO-ZrO2/HZSM-5 catalysts

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq150711005z ◽

2017 ◽

Vol 23 (1) ◽

pp. 49-56 ◽

Cited By ~ 2

Author(s):

Yajing Zhang ◽

Yu Zhang ◽

Fu Ding ◽

Kangjun Wang ◽

Wang Xiaolei ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Direct Synthesis ◽

Catalytic Performance ◽

Co2 Hydrogenation ◽

Precipitation Method ◽

X Ray ◽

Temperature Programmed ◽

And Performance ◽

Co Precipitation ◽

Adsorption Desorption

A series of La2O3-modified CuO-ZnO-ZrO2/HZSM-5 catalysts were prepared by an oxalate co-precipitation method. The catalysts were fully characterized by X-ray diffraction (XRD), N2 adsorption-desorption, hydrogen temperature pro-grammed reduction (H2-TPR), ammonia temperature programmed desorption (NH3-TPD), and X-ray photoelectron spectroscopy (XPS) techniques. The effect of the La2O3 content on the structure and performance of the catalysts was thoroughly investigated. The catalysts were evaluated for the direct synthesis of dimethyl ether (DME) from CO2 hydrogenation. The results displayed that La2O3 addition enhanced catalytic performance, and the maximal CO2 conversion (34.3%) and DME selectivity (57.3%) were obtained over the catalyst with 1% La2O3, which due to the smaller size of Cu species and a larger ratio of Cu+/Cu.

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Anisotropic O vacancy formation and diffusion in LaMnO3

Journal of Materials Chemistry A ◽

10.1039/c4ta04119d ◽

2014 ◽

Vol 2 (46) ◽

pp. 19733-19737 ◽

Cited By ~ 13

Author(s):

Li-Yong Gan ◽

Salawu Omotayo Akande ◽

Udo Schwingenschlögl

Keyword(s):

Vacancy Formation ◽

O Vacancy ◽

And Diffusion

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Thermodynamics of Oxygen Chemistry on PbTiO3 and LaMnO3 (001) Surfaces

MRS Proceedings ◽

10.1557/opl.2011.731 ◽

2011 ◽

Vol 1309 ◽

Author(s):

Ghanshyam Pilania ◽

R. Ramprasad

Keyword(s):

Phase Diagram ◽

High Temperatures ◽

First Principles ◽

Room Temperature ◽

Oxidation Catalysis ◽

Vacancy Formation ◽

Surface Phase ◽

Surface Phases ◽

O Vacancy ◽

Low Pressures

ABSTRACTWe present a first principles thermodynamic study of O ad-atom and vacancy formation on the AO- and BO2-terminated (001) surfaces of the PbTiO3 (PTO) and LaMnO3 (LMO) cubic perovskites. Our results show that, owing to the highly energetically unfavorable nature of O vacancy formation on these surfaces, O vacancies appear only at high temperatures and practically irrelevant low pressures on the (T, p) surface phase diagram. In contrast, effortless formation of O ad-atoms on the surfaces is encountered at practically achievable pressures and temperatures. Above room temperature and close to atmospheric pressures, we predict clean PbO and TiO2-terminated (001) PTO surfaces as the stable surface phases while partially or fully O ad-atom covered surfaces are found to be more stable for LMO. These results are consistent with the observation that LMO is far more active towards oxidation catalysis than PTO.

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