On the Catalytic Activity of Co3O4 in Low-Temperature CO Oxidation

doi:10.1006/jcat.2002.3738

Journal of Catalysis

Volume 211, Issue 2, 25 October 2002, Pages 387-397

https://doi.org/10.1006/jcat.2002.3738 Get rights and content

Abstract

Oxidation of CO over Co₃O₄ at ambient temperature was studied with flow reactor experiments, and in-situ spectroscopic and structural methods. The catalyst deactivates during the reaction. The rate of deactivation increased with increasing CO or CO₂ gas-phase concentration but decreased with increased O₂ concentration or increased temperature. Regeneration of the catalyst in 10% O₂/Ar was more efficient than regeneration in Ar alone. The presence of carbonates and surface carbon on the deactivated catalyst was concluded from TPO experiments. None of these species could, however, be correlated with the deactivation of the catalyst. In-situ FTIR showed the presence of surface carbonates, carbonyl, and oxygen species. The change in structure and oxidation state of the catalyst was studied by in-situ XRD, in-situ XANES, XPS, and flow reactor experiments. One possible explanation for the deactivation of the catalyst is a surface reconstruction hindering the redox cycle of the reaction.

References (48)

M. Shelef et al.
Catal. Today
(2000)
G. Lenaers
Sci. Total Environ.
(1996)
R.C. Rijkeboer
Catal. Today
(1991)
D.S. Lafyatis et al.
Appl. Catal. B
(1998)
K. Umehara et al.
JSAE Rev.
(1997)
S.D. Gardner et al.
J. Catal.
(1991)
N. Watanabe et al.
Appl. Catal. B
(1996)
M. Haruta et al.
J. Catal.
(1993)
H. Yamaura et al.
Sens. and Actuators, B
(2000)
N. Funazaki et al.
Sens. Actuators B
(1993)

P. Thormählen et al.

J. Catal.

(1999)

L. Simonot et al.

Appl. Catal. B

(1997)

L. Simonot et al.

Stud. Surf. Sci. Catal.

(1995)

Y.J. Mergler et al.

J. Catal.

(1997)

Y.J. Mergler et al.

Stud. Surf. Sci. Catal.

(1995)

Y.J. Mergler et al.

Appl. Catal. B

(1996)

J. Jansson

J. Catal.

(2000)

Y. Takita et al.

J. Catal.

(1986)

Y.J. Mergler et al.

J. Catal.

(1996)

M. Schönnenbeck et al.

Surf. Sci.

(1996)

St.G. Christoskova et al.

Mater. Chem. Phys.

(1999)

P. Arnoldy et al.

J. Catal.

(1985)

H.F.J. van't Blik et al.

J. Catal.

(1986)

Cited by (416)

Preparation of highly active and SO<inf>2</inf>-resistant Cr-based non-carbon adsorbents via plasma for elemental mercury removal
2024, Separation and Purification Technology
Coal-fired mercury pollution poses an escalating threat to the ecosystem and human health. In this study, we designed and prepared transition metal oxides (MO_x) supported non-carbon-based adsorbents for Hg⁰ removal using non-thermal plasma, based on the mechanism of Hg⁰ removal. Specifically, MO_x supported SiO₂ adsorbents were examined to explore the correlation between their redox ability and Hg⁰ removal. The plasma treatment process could enhance the catalytic oxidation activity of the MO_x (oxygen activation center) and effectively enhance Hg⁰ removal efficiency. The Hg⁰ removal efficiencies of Co₃O₄/SiO₂-P and CrO_x/SiO₂-P prepared by plasma could maintain above 95.0 % and 85.0 % in the whole test, whereas the Co₃O₄/SiO₂ and CrO_x/SiO₂ adsorbents prepared by traditional incipient wetness impregnation method exhibited lower Hg⁰ removal efficiencies of nearly 20–30 %. Furthermore, with the addition of SO₂, the Hg⁰ removal performance of Co₃O₄/SiO₂-P decreased significantly, while the performance of CrO_x/SiO₂-P remained relatively unchanged. Characterization results containing X-ray photoelectron spectroscopy (XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) showed that the oxygen activation centers on CrO_x/SiO₂-P exhibited excellent resistance to SO₂ and were less susceptible to SO₂ occupation than those on Co₃O₄/SiO₂-P. The plasma-prepared CrO_x/SiO₂-P adsorbents demonstrate promising potential for industrial applications in Hg⁰ removal.
A review on topical advancement and challenges of indium oxide based gas sensors: Future outlooks
2024, Journal of Environmental Chemical Engineering
The advancement of industry and the hastening of urbanization have led to serious problems associated with the emanation of various harmful and lethal gases, which are a threat to humankind. Therefore, the fabrication of highly sensitive and selective sensors for monitoring these gases is desirable. Due to its stability, sensitivity, and selectivity in the general environment, indium oxide (In₂O₃) has attracted considerable attention for gas sensing. Thus, the current review discusses the latest research made over the last five years on In₂O₃-based gas sensors. The influence of environmental pollutants, such as VOCs, NO_X, CO, O₃, NH₃, and SO₂ on the environment and human life were discussed. Among the synthesis methods, the hydrothermal approach has been the most used for the preparation of sensors based on In₂O₃. The drawbacks and challenges linked with the In₂O₃ sensors for the last five (5) years, showed that most of the sensors have been functioning at higher temperatures. This has led to a lack of commercialization because of reliability issues associated with the long-term stability drift. So far, noble metals doped-In₂O₃ sensors have shown promising advantages for room temperature operation, which could be useful for reaching the next generation of intelligent gas sensors from micro/nanomaterials to the era of self-powered, artificially intelligent system and their integration on smartphones. Thus, In₂O₃ gas sensors with Bluetooth modules can make it feasible to wirelessly monitor the concentration of different gases without the need for an external power source and transmit information via a smartphone. This would further be suitable in wireless signal detection, the Internet of Things, in data processing, particularly in machine learning, to aid in gas sensing.
Growth of ultrathin cobalt oxide films on Pd(100): Refined structural model
2024, Surface Science
We present an atomistic-level study on the growth of cobalt oxide ultra-thin films prepared on Pd(100) substrate performed by a combination of scanning tunneling microscopy (STM) and Low Energy Electron Diffraction (LEED). In this contribution, we report a new surface structure c(12×2)-CoO(111), which co-exist with the previously reported extended c(4 × 2)-CoO(100) domains at low Co deposition coverages. We demonstrate that the lattice parameters derived for the newly observed hexagonal c(12×2)-CoO(111) phase fit the three- or sixfold lattice parameter of the c(4 × 2)-CoO(100) layer. The c(12×2)-CoO(111) layer was shown to grow directly on top of the c(4 × 2)-CoO(100) structure, offering a transition mechanism from rectangularly to hexagonally terminated CoO surface. At growing Co coverages, HEX-CoO(111) domains exhibiting a Moiré pattern followed by the formation of well-defined Co₃O₄(111) islands, were prepared and structurally characterized. Both latter phases have been previously reported in the literature. Finally, we provide a refined model for the epitaxial growth of cobalt oxide thin films on Pd(100), including the formation of new c(12×2)-CoO(111) phase.
MIL-68 derived In<inf>2</inf>O<inf>3</inf> microtubes and Co<inf>3</inf>O<inf>4</inf>/In<inf>2</inf>O<inf>3</inf> heterostructures for high sensitive formaldehyde gas sensors
2024, Ceramics International
The gas sensors with high response and selectivity are important for detecting and monitoring formaldehyde gas in real-time. In this paper, In₂O₃ microtubes are derived from metal organic framework named MIL-68 and Co₃O₄ nanoparticles are successfully loaded on the surface of In₂O₃ microtubes to form Co₃O₄/In₂O₃ heterostructures via one-step hydrothermal and calcination methods. The crystal structure, surface morphology and components of all samples are characterized and the formaldehyde gas-sensing performance is investigated in detail. All results indicates that Co₃O₄ nanoparticles greatly improve the formaldehyde gas-sensing performance of Co₃O₄/In₂O₃ heterostructures. Specifically, Co₃O₄/In₂O₃ (9 wt%) sensor exhibits a higher response (1215.47) to 10 ppm formaldehyde gas, which is about 10.16 times than that of pristine In₂O₃ sensor. Furthermore, Co₃O₄/In₂O₃ (9 wt%) sensor possesses a shorter recovery time (81 s), lower working temperature (190 °C), excellent selectivity, superior linear properties. As a result, Co₃O₄/In₂O₃ sensors exhibit excellent gas-sensing properties because of the synergistic effect of the catalytic activity of Co₃O₄ nanoparticles, the formation of p-n heterojunction and the increasing surface oxygen.
Zeolite fixed cobalt–nickel nanoparticles for coking and sintering resistance in dry reforming of methane
2023, Chemical Engineering Science
Dry reforming of methane (DRM) displays a crucial role in CO₂ fixation, but the current catalysts suffer from deactivation from thermodynamically oriented coking and metal sintering. Herein, we reported a catalyst by fixing the cobalt–nickel nanoparticles within the zeolite crystals (CoNi@zeolite), where the SiO_x-O-M^δ+ (M = Ni or Co) linkage enhanced the reduction resistance of Co and Ni species compared with the generally supported catalysts, efficiently hindering the deep dehydrogenation of methane, which is well known as a reaction channel for coke formation. In addition, the rigid and thermally stable zeolite framework stabilized the cobalt–nickel nanoparticles to avoid their sintering during the reaction. As a result, the CoNi@zeolite catalyst exhibited a long reaction lifetime and great regenerability in a test for 980 h with reaction gas flow at 1200 L per unit mass of metal species per hour, outperforming conventionally supported metal catalysts. This work enables a proof-of-the-concept design of durable catalysts by zeolite fixation for the reactions in strongly reductive atmospheres.
Toluene decomposition by non-thermal plasma assisted CoO<inf>x</inf> − γ-Al<inf>2</inf>O<inf>3</inf>: The relative contributions of specific energy input of plasma, Co<sup>3+</sup> and oxygen vacancy
2023, Journal of Hazardous Materials
Cobalt oxide (CoO_x) is a common catalyst for plasma catalytic elimination of volatile organic compounds (VOCs). However, the catalytic mechanism of CoO_x under radiation of plasma is still unclear, such as how the relative importance of the intrinsic structure of the catalyst (e.g., Co³⁺ and oxygen vacancy) and the specific energy input (SEI) of the plasma for toluene decomposition performance. CoO_x − γ-Al₂O₃ catalysts were prepared and evaluated by toluene decomposition performance. Changing the calcination temperature of the catalyst altered the content of Co³⁺ and oxygen vacancies in CoO_x, resulting in different catalytic performance. The results of the artificial neural network (ANN) models presented that the relative importance of three reaction parameters (SEI, Co³⁺, and oxygen vacancy) on the mineralization rate and CO₂ selectivity were as follows: SEI > oxygen vacancy > Co³⁺ , and SEI > Co³⁺ > oxygen vacancy, respectively. Oxygen vacancy is essential for mineralization rate, and CO₂ selectivity is more dependent on Co³⁺ content. Furthermore, a possible reaction mechanism of toluene decomposition was proposed according to the analysis results of in-situ DRIFTS and PTR-TOF-MS. This work provides new ideas for the rational design of CoO_x catalysts in plasma catalytic systems.

View all citing articles on Scopus

¹: To whom correspondence should be addressed. Fax: +46 31 772 30 35. E-mail: [email protected].

View full text

Regular ArticleOn the Catalytic Activity of Co3O4 in Low-Temperature CO Oxidation

Abstract

Catal. Today

Sci. Total Environ.

Catal. Today

Appl. Catal. B

JSAE Rev.

J. Catal.

Appl. Catal. B

J. Catal.

Sens. and Actuators, B

Sens. Actuators B

J. Catal.

Appl. Catal. B

Stud. Surf. Sci. Catal.

J. Catal.

Stud. Surf. Sci. Catal.

Appl. Catal. B

J. Catal.

J. Catal.

J. Catal.

Surf. Sci.

Mater. Chem. Phys.

J. Catal.

J. Catal.

Regular Article
On the Catalytic Activity of Co₃O₄ in Low-Temperature CO Oxidation