Study of synergistic effect between CuO and CeO2 over CuO@CeO2 core–shell nanocomposites for NH3-SCO

Zhang, Xiaoyu; Wang, Hui; Jiang, Xiao; Sun, Hongchun; Qu, Zhenping

doi:10.1039/c9cy00480g

Cited by 48 publications

(23 citation statements)

References 55 publications

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“…The peak observed at 531.37 is assigned to the oxygen atoms in the vicinity of oxygen vacancies (O V ) . The last peak at 533.06 eV can be attributed to surface adsorbed oxygen such as hydroxy groups (M−OH) and/or water molecules (O OH ) …”

Section: Resultsmentioning

confidence: 99%

Surface Modification of Hematite Photoanodes with CeO_x Cocatalyst for Improved Photoelectrochemical Water Oxidation Kinetics

et al. 2020

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Hematite is a promising photoanode for solar water splitting by photoelectrochemical (PEC) cells, but its performance is limited by the slow kinetics of water oxidation reaction or oxygen evolution reaction (OER). Surface modification of hematite photoanodes with a suitable water oxidation cocatalyst is a key strategy for improving the kinetics of water oxidation. In this study, a CeO x overlayer is deposited on the surface of the hematite photoanode by a water-based solution method with ceric ammonium nitrate (CAN) followed by heat treatment. The photocurrent of CeO x-modified hematite is 3 times higher than that of pristine hematite (at 1.23 V vs. RHE) under AM 1.5G, 1 sun conditions. Through hole-scavenger measurements, Tafel plot analysis, and electrochemical impedance spectroscopy, it is concluded that CeO x overlayer increases the hole injection efficiency, improves the surface catalytic activity, and enhances charge transfer across the photoanode/electrolyte interface. These observations are attributed to the synergistic effects of Ce 3 + /Ce 4 + redox species in CeO x and the oxygen vacancies. This work elucidates the role of CeO x as an efficient cocatalyst overlayer to improve the OER kinetics of photoanodes.

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Section: Resultsmentioning

confidence: 99%

Surface Modification of Hematite Photoanodes with CeO_x Cocatalyst for Improved Photoelectrochemical Water Oxidation Kinetics

et al. 2020

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“…The resulting more rapid reduction–oxidation cycle explained the higher activity of the CuO-CeO 2 catalyst. Similarly, a core–shell CuO@CeO 2 catalyst was successfully prepared by a template-assisted method . This structure greatly promoted the synergistic effect of CuO and CeO 2 , whereby more of the Cu-O-Ce solid solution was formed on the catalyst surface.…”

Section: Scr + Nh3 Eliminationmentioning

confidence: 99%

“…Similarly, a core−shell CuO@CeO 2 catalyst was successfully prepared by a template-assisted method. 154 This structure greatly promoted the synergistic effect of CuO and CeO 2 , whereby more of the Cu-O-Ce solid solution was formed on the catalyst surface. Compared with the CuO/CeO 2 catalyst, the core−shell CuO@CeO 2 catalyst exhibited higher performance with a lower T 100 of 240 °C and a high N 2 selectivity of 90%, which was ascribed to the promoted absorption and activation of ammonia by the Cu-O-Ce solid solution.…”

Section: Scr + Nh 3 Eliminationmentioning

confidence: 99%

Multipollutant Control (MPC) of Flue Gas from Stationary Sources Using SCR Technology: A Critical Review

Wang

Chen

Zhang

et al. 2021

Environ. Sci. Technol.

131

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The emission of gaseous pollutants from the combustion of fossil fuels is believed to be one of the most serious environmental challenges in the 21st century. Given the increasing demands of multipollutant control (MPC) via adsorption or catalysis technologies, such as NO x , volatile organic compounds (VOCs), heavy metals (Hg etc.), and ammonia, and considering investment costs and site space, the use of existing equipment, especially the selective catalytic reduction (SCR) system to convert pollutants into harmless or readily adsorbed substances, is one of the most practical approaches. Consequently, many efforts have been directed at achieving the simultaneous elimination of multipollutants in a SCR convertor, and this method has been widely used to mitigate the stationary emission of NO x . However, the development of active, selective, stable, and multifunctional catalysts/adsorbents suitable for large-scale commercialization remains challenging. Herein, we summarize recent works on the applications of SCR in MPC, describing the approaches of (i) SCR + VOCs oxidation, (ii) SCR + heavy metal control, and (iii) SCR + NH3 reduction to reveal that the efficiency of simultaneous elimination depends on catalyst composition and flue gas parameters. Furthermore, the synergistic promotional/inhibitory effects between SCR and VOCs/ammonia/heavy metal oxidations are shown to be the key to the feasibility of the reactions.

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“…In metal-based catalysts, silver- or copper-based catalysts were proven to be the most effective ones for NH 3 -SCO. Although copper catalysts such as copper-exchanged zeolites and copper oxides exhibited high N 2 selectivity, they represented low activity at <350 °C. − For example, Gang et al , investigated the effect of different content of copper (5.0–15.0%) for NH 3 oxidation with Cu/Al 2 O 3 catalysts, in which a complete oxidation of NH 3 with 90% selectivity toward N 2 could be obtained with 10.0% loading at 350 °C. However, the NH 3 conversion was only 15% at 250 °C.…”

Section: Introductionmentioning

confidence: 99%

High-Performance Ag–Cu Nanoalloy Catalyst for the Selective Catalytic Oxidation of Ammonia

Zhou

Zhong

Sun

et al. 2019

ACS Appl. Mater. Interfaces

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High-performance Ag–Cu alloy nanoparticles (NPs) were successfully synthesized by a solventless mix–bake–wash method and tested for NH3-SCO. The prepared Ag2Cu1 catalyst with a perfect Ag–Cu alloy structure exhibited better T 100 (200 °C, the temperature at which 100% NH3 conversion was obtained), higher reaction rates, and lower E a compared to that with ordinary bimetallic Ag–Cu (AgCuO x ). The characterization data revealed much smaller Ag–Cu alloy nanoparticles of the Ag2Cu1 catalyst and more Ag/Cu metallic species on the surface, which can increase the amount of chemisorbed surface oxygen (Oβ) and enhance NH3 adsorption and activation in the low-temperature range, therefore leading to a much higher NH3-SCO activity. Kinetic studies and density functional theory calculations indicated that Cu decoration at Ag by Ag–Cu alloying could enhance the adsorption/activation of NH3 and O2. It has been found that O2 was more easily transformed from the adsorption state to the transition state than NH3, which enhanced the performance of NH3 oxidation. In addition, the Ag2Cu1 catalyst exhibited excellent durability because of the stabilization of Ag sites by the Ag–Cu alloy structure.

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Study of synergistic effect between CuO and CeO₂ over CuO@CeO₂ core–shell nanocomposites for NH₃-SCO

Abstract: CuO@CeO2 core–shell nanocomposites were fabricated and applied in NH3-SCO. Synergistic effect of CuO–CeO2 promotes the formation of the Cu–O–Ce structure, which is beneficial to N2 selectivity.

Cited by 48 publications

References 55 publications

Surface Modification of Hematite Photoanodes with CeO_x Cocatalyst for Improved Photoelectrochemical Water Oxidation Kinetics

Surface Modification of Hematite Photoanodes with CeO_x Cocatalyst for Improved Photoelectrochemical Water Oxidation Kinetics

Multipollutant Control (MPC) of Flue Gas from Stationary Sources Using SCR Technology: A Critical Review

High-Performance Ag–Cu Nanoalloy Catalyst for the Selective Catalytic Oxidation of Ammonia

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Study of synergistic effect between CuO and CeO2 over CuO@CeO2 core–shell nanocomposites for NH3-SCO

Abstract: CuO@CeO2 core–shell nanocomposites were fabricated and applied in NH3-SCO. Synergistic effect of CuO–CeO2 promotes the formation of the Cu–O–Ce structure, which is beneficial to N2 selectivity.

Cited by 48 publications

References 55 publications

Surface Modification of Hematite Photoanodes with CeOx Cocatalyst for Improved Photoelectrochemical Water Oxidation Kinetics

Surface Modification of Hematite Photoanodes with CeOx Cocatalyst for Improved Photoelectrochemical Water Oxidation Kinetics

Multipollutant Control (MPC) of Flue Gas from Stationary Sources Using SCR Technology: A Critical Review

High-Performance Ag–Cu Nanoalloy Catalyst for the Selective Catalytic Oxidation of Ammonia

Contact Info

Product

Resources

About

Study of synergistic effect between CuO and CeO₂ over CuO@CeO₂ core–shell nanocomposites for NH₃-SCO

Surface Modification of Hematite Photoanodes with CeO_x Cocatalyst for Improved Photoelectrochemical Water Oxidation Kinetics

Surface Modification of Hematite Photoanodes with CeO_x Cocatalyst for Improved Photoelectrochemical Water Oxidation Kinetics