| 1. |
- Ho, Hoang Phuoc, 1983, et al.
(author)
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Role of the supports during phosphorus poisoning of diesel oxidation catalysts
- 2023
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In: Chemical Engineering Journal. - 1385-8947. ; 468
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Journal article (peer-reviewed)abstract
- Phosphorus (P) poisoning is one of the main factors accounting for the deactivation of diesel oxidation catalysts (DOC) apart from sulfur poisoning and sintering of the Pt active sites. This study compares the impact of P with loading up to 2.4 wt% on the catalytic performance of monometallic and bimetallic Pt-Pd catalysts using alumina and high silica BEA zeolites as the supports. P poisoning caused deactivation for CO, C3H6, C3H8 and NO oxidation; however, the degree of the impact of P in terms of temperatures at which 50% of the component is converted (T50) depends not only on the types of the active phase (Pt and Pt-Pd) but also on the types of supports (alumina and BEA zeolite). The influence of P impregnation on the textural properties of the materials is more significant for zeolite than alumina-based catalysts, which is in line with the activity measurements. A weak interaction between P and high silica zeolite resulted in the formation of a prominent fraction of P2O5 in the P-Pt/BEA, whereas a strong binding between P and alumina accounted for a dominant fraction of phosphate in the P-Pt/Al2O3 as revealed by XPS and NMR measurements. Phosphorus compounds partially covered the available surface of the active sites and this lowered the catalytic activity. For alumina-based catalysts, P mainly reacted with the support and only deactivated a part of the active noble metals. Whereas, for zeolite-based catalysts, P existed mainly in the form of phosphorus oxides that significantly blocked the catalyst surface and thereby deactivated more of the available active sites than that on alumina-based materials, which is consistent with the CO chemisorption data.
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| 2. |
- Tang, Weidong, et al.
(author)
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The roles of metal oxidation states in perovskite semiconductors
- 2023
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In: Matter. - : CELL PRESS. - 2590-2393 .- 2590-2385. ; 6:11, s. 3782-3802
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Research review (peer-reviewed)abstract
- Metal halide perovskites are an emerging materials platform for optoelectronic, spintronic, and thermoelectric applications. The field of perovskite materials and devices has progressed rapidly over the past decade. For halide perovskite materials, a range of physical and chemical properties such as crystal structure, bandgap, charge carrier density, and stability that govern the device functionalities are critically determined by the oxidation states of the B-site metal ions. However, such an important mechanistic connection unique to halide perovskites is not well established, limiting the pace of development in this area. In this review, we identify the roles of metal oxidation states in perovskite semiconductors. The redox reactions leading to these states, and their effects on the materials properties, are clarified. Finally, we suggest routes to improving device efficiency and stability from the perspective of oxidation state control.
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| 3. |
- Yao, Dawei, 1991, et al.
(author)
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Deciphering SO2 poisoning mechanisms for passive NOx adsorption: A kinetic modeling approach and development of a high-resistance catalyst
- 2024
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In: Chemical Engineering Journal. - 1385-8947. ; 487
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Journal article (peer-reviewed)abstract
- Passive NOx adsorption (PNA) is a promising technology aimed at reducing NOx emissions from vehicles during the cold start phase of the engine. This work investigated the SO2 poisoning mechanism of PNA through a combination of experimental research and kinetic modeling, leading to the development of a novel PNA sample with high resistance to SO2 poisoning. Pd/SSZ-13 samples were synthesized using different drying conditions, revealing that samples dried at room temperature showed lower degradation (10 %) compared to those dried at 80 °C (26 %). Investigation into the degradation revealed that ion-exchanged Pd sites with a hydroxyl group were more resistant to SO2 poisoning than other Pd sites. It is also found that SO2 aids in NOx storage on Pd sites, enhancing the PNA performance. A kinetic model was developed to describe the SO2 poisoning behavior and its influence on NOx storage. The model, which was verified under various conditions, effectively simulated the PNA behavior and SO2 poisoning of Pd/SSZ-13.
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| 4. |
- Zhang, Lixiu, et al.
(author)
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Advances in the Application of Perovskite Materials
- 2023
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In: NANO-MICRO LETTERS. - : SHANGHAI JIAO TONG UNIV PRESS. - 2311-6706. ; 15:1
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Research review (peer-reviewed)abstract
- Nowadays, the soar of photovoltaic performance of perovskite solar cells has set off a fever in the study of metal halide perovskite materials. The excellent optoelectronic properties and defect tolerance feature allow metal halide perovskite to be employed in a wide variety of applications. This article provides a holistic review over the current progress and future prospects of metal halide perovskite materials in representative promising applications, including traditional optoelectronic devices (solar cells, light-emitting diodes, photodetectors, lasers), and cutting-edge technologies in terms of neuromorphic devices (artificial synapses and memristors) and pressure-induced emission. This review highlights the fundamentals, the current progress and the remaining challenges for each application, aiming to provide a comprehensive overview of the development status and a navigation of future research for metal halide perovskite materials and devices.
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| 5. |
- Zhao, Baodan, et al.
(author)
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Light management for perovskite light-emitting diodes
- 2023
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In: Nature Nanotechnology. - : NATURE PORTFOLIO. - 1748-3387 .- 1748-3395. ; 18:9, s. 981-992
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Research review (peer-reviewed)abstract
- Perovskite light-emitting diodes (LEDs) have reached external quantum efficiencies of over 20% for various colours, showing great potential for display and lighting applications. Despite the internal quantum efficiencies of the best-performing devices already approaching unity, around 80% of the internally generated photons are trapped in the devices and lose energy through a variety of lossy channels. Significant opportunities for improving efficiency and maximizing photon extraction lie in the effective management of light. In this Review we analyse light management strategies based on the intrinsic optical properties of the perovskite materials and the extrinsic properties related to device structures. These approaches should allow the external quantum efficiencies of perovskite LEDs to substantially exceed the conventional limits of planar organic LED devices. By revisiting lessons learned from organic LEDs and perovskite solar cells, we highlight possible directions of future research towards perovskite LEDs with ultrahigh efficiencies. This Review analyses the mechanisms of light extraction from perovskite light-emitting diodes and suggests new approaches towards ultrahigh electroluminescence efficiencies.
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