Article
Chemistry, Physical
Xudong Du, Yun Lang, Kun Cao, Jiaqiang Yang, Jiaming Cai, Bin Shan, Rong Chen
Summary: This paper designs bifunctional Pt/Ru nanoparticle catalysts via selective atomic layer deposition for PROX in H-2, showcasing optimal activity and selectivity. The enhancement in PROX performance is attributed to the elimination of competitive CO adsorption on Pt, allowing neighboring exposed Ru surfaces to provide highly active sites for O-2 dissociation.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Physical
Chongya Yang, Tianyu Zhang, Yusen Chen, Weijue Wang, Hongying Zhuo, Xiaofeng Yang, Yanqiang Huang
Summary: By using the atomic layer deposition (ALD) technique to deposit alumina on the Ru/SiC model nanocatalysts, the corrugated (1011) surface of Ru nanoparticles can be selectively insulated, and the intrinsic activity of CO2 conversion was found to depend on the residual planar (0001) surface. The competitive kinetics of H2 and CO2 activation on the Ru surface govern the activity and selectivity of methanation. The terrace sites of Ru nanocatalysts serve as the active site through the HCOO* intermediate, while the (1011) surface has a negligible contribution toward methanation due to its preference for CO2 adsorption and surface poisoning.
Article
Nanoscience & Nanotechnology
Azina Rahmani, Maksim A. Sultanov, Kemah Kamiru-White, Lorianne R. Shultz-Johnson, Brian E. Butkus, Shaohua Xie, Fudong Liu, Diep T. H. Nguyen, Noeimie Wilson-Faubert, Ali Nazemi, Parag Banerjee, Lei Zhai, Massimiliano Delferro, Jianguo Wen, Titel Jurca
Summary: Galvanic exchange and atomic layer deposition techniques were used to prepare ultralow loading Pt catalysts with high stability and recyclability. The catalysts showed high activity towards various functionalized styrenes and excellent tolerance towards substituents.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Hyun Soo Park, Heon Jun Jeong, Keun-hee Kim, Wanhyuk Chang, Yoon Seong Kim, Yoon Seong Choi, Joon Hyung Shim
Summary: This study demonstrates the performance improvement of a protonic ceramic fuel cell (PCFC) by applying a CoOx nanoparticle treatment to a PrBa(0.5)Sr(0.5)Co(2-x)FexO(5+delta)(PBSCF) cathode with a perovskite structure. The deposition of CoOx nanoparticles on the surface of the cathode using plasma-enhanced atomic layer deposition (ALD) process results in uniform distribution and a constant deposition rate. The treated cells show a 36% increase in performance compared to untreated cells at an operating temperature of 650 degrees C, indicating the potential of the proposed method for high-performance PCFC fabrication and lower operating temperatures.
APPLIED SURFACE SCIENCE
(2023)
Article
Energy & Fuels
Qiuping Yang, Daowei Gao, Chunsheng Li, Siyi Cao, Shun Li, Huaiqing Zhao, Cuncheng Li, Gengxiu Zheng, Guozhu Chen
Summary: “The selective hydrogenation of furfural to furfuryl alcohol has attracted extensive attention, but designing and preparing efficient catalysts with high selectivity remains challenging due to the presence of conjugated C-O and C-C groups in furfural. In this study, small-sized Pt nanoclusters were loaded onto MOFs-derived CeO2 using atomic layer deposition. The Pt/M-CeO2 catalyst exhibited superior catalytic activity and selectivity compared to Pt/commercial CeO2, achieving 100% conversion of furfural with 98% selectivity to furfuryl alcohol. The excellent catalytic performance of Pt/M-CeO2 can be attributed to the clean surface of Pt clusters, strong interaction between Pt and M-CeO2, and the rich oxygen vacancy/porous structure of the M-CeO2 support. This work highlights an effective approach for depositing noble metal clusters onto MOFs-derived metal oxides, providing an alternative strategy for the rational design of highly efficient catalysts in selective hydrogenation reactions.”
Article
Chemistry, Physical
Qin Liu, Shibo Xi, Xinnan Peng, Lei Feng, Guangyuan Xu, Zhendong Liu, Yuan Kong, Xiaoxu Zhao, Huan Yan
Summary: This study proposes a new strategy for investigating the coordination environment of catalytic centers and its effect on reactivity. By altering the surrounding atoms instead of the catalytic metal center, a clear relationship between coordination environment and catalytic activity was observed. DFT calculations provided a comprehensive map of the relationship between coordination environments and catalytic performances. This coordination environment engineering method can be widely applied to screen new catalysts and offers a novel way to investigate the fundamental chemistry of active sites in catalysis.
Article
Thermodynamics
Tianyu Cao, Ohhun Kwon, John M. Vohs, Raymond J. Gorte
Summary: LaFeO3 films were deposited onto amorphous SiO2 by Atomic Layer Deposition to serve as supports for Pt. The films showed uniform coverage and high Pt dispersion following high-temperature reduction, indicating the formation of perovskite phase on a short length scale. The implications of using these materials were discussed in terms of their activity and stability.
INTERNATIONAL JOURNAL OF GREEN ENERGY
(2022)
Article
Chemistry, Physical
Sungje Lee, Yunsung Kang, Jaehyeong Lee, Jingyung Kim, Jeong Woo Shin, Sangjun Sim, Dohyun Go, Eunhwan Jo, Seunghyeon Kye, Jongbaeg Kim, Jihwan An
Summary: The use of platinum (Pt) catalysts decorated on molybdenum disulfide (MoS2) using atomic layer deposition (ALD) can create highly sensitive hydrogen (H-2) sensors; oxygen plasma pretreatment is employed to facilitate homogeneous distribution of Pt nanoparticles on MoS2 surfaces; the sensor achieves a sensitivity over 400 and a lower detection limit of 2.5 ppm for H-2 detection.
APPLIED SURFACE SCIENCE
(2022)
Article
Electrochemistry
Yuehong Zeng, Huiming Wang, Muhammad Rauf, Hongwei Mi, Lingna Sun, Qixing Wu, Qianling Zhang, Xiangzhong Ren, Yongliang Li
Summary: In this study, a synergistic effect between carbon nanotube (CNT) network and atomic layer deposition (ALD) of TiO2 is reported. The CNTs and TiO2 work together to capture zinc ions and suppress dendrite growth, resulting in uniform deposition during repeated cycles. The modified anode (TiO2-CNT@Zn anode) exhibits high plating/stripping reversibility and ultralong lifespan. Furthermore, the Zn-MnO2 battery with the TiO2-CNT@Zn anode shows enhanced cycling stability.
ELECTROCHIMICA ACTA
(2023)
Article
Electrochemistry
Bilal Bawab, Sitaramanjaneya M. Thalluri, Jhonatan Rodriguez-Pereira, Hanna Sopha, Raul Zazpe, Jan M. Macak
Summary: Pd nanoparticles prepared by ALD show good performance in methanol electro-oxidation, with TNT layers as the supporting material effectively preventing the formation of electrochemical poisoning species. Different Pd loadings influence the particle size of Pd and electrocatalytic performance.
ELECTROCHIMICA ACTA
(2022)
Article
Chemistry, Multidisciplinary
Cara-Lena Nies, Suresh Kondati Natarajan, Michael Nolan
Summary: Prolonging the lifetime of Cu as an interconnect metal in future nanoelectronic devices is a significant challenge, and researchers are investigating new materials that combine diffusion barrier and seed liner properties to enhance electrical conductance.
Article
Chemistry, Physical
Siwon Lee, Chao Lin, Seunghyun Kim, Xinyu Mao, Taeho Kim, Sang-Joon Kim, Raymond J. Gorte, WooChul Jung
Summary: The influence of manganese oxide on CO oxidation over Pt catalysts was investigated. MnOx modification improved catalyst durability and CO oxidation rates by creating active Pt-MnOx interfacial sites. Despite suppressed CO adsorption after high-temperature calcination, TEM showed uniform coverage of Pt by a thin film of MnOx.
Article
Chemistry, Physical
Dan Li, Jianguo Li, Lijun Qin, Yiyun Hu, Ting Gong, Wangle Zhang, Longfei Hui, Hao Feng
Summary: By synthesizing high surface area H-titanate nanotubes through a hydrothermal route, and depositing iron oxide (Fe2O3) on them using atomic layer deposition (ALD), H-titanate@Fe2O3 composites were produced and used as combustion catalysts for thermal decomposition of ammonium perchlorate (AP). The results show that H-titanate@Fe2O3 catalysts effectively promote the thermal decomposition of AP, reducing the decomposition temperature and apparent activation energy. The excellent catalytic activity of H-titanate@Fe2O3 catalysts is attributed to the finely dispersed Fe2O3 nanoparticles anchored on the surface of H-titanate, generating very active interface sites for the decomposition of AP, demonstrating the potential of interface engineering in preparing efficient propellant combustion catalysts.
APPLIED SURFACE SCIENCE
(2021)
Article
Engineering, Environmental
Qiheng Wang, Haojie Liang, Jingwei Zhou, Jingkun Wang, Zhuang Ye, Min Zhao, Huimin Yang, Yanhui Song, Junjie Guo
Summary: Introducing heterometals into Pt/C catalyst to construct multi-metal catalyst is a rational strategy that can optimize the over-strong *O adsorption of Pt nanoparticles for oxygen reduction reaction (ORR). The constructed Pt-Fe-NG structure by atomic layer deposition shows outstanding ORR performance, with a half-wave potential of 0.948 V, a total four-electron pathway, and superior durability over 10,000 cycles. The Fe bridging atoms in the structure play a crucial role in enhancing the interaction between Pt nanoparticles and carbon support.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Joel R. Schneider, Camila Paula, Jacqueline Lewis, Jacob Woodruff, James A. Raiford, Stacey F. Bent
Summary: Recent research has reported that a zero-valent complex, Ru(DMBD)(CO)(3), achieved good nucleation in atomic layer deposition (ALD) at relatively low temperatures and mild reaction conditions. The precursor produced high-quality Ru films with excellent nucleation properties. However, the deposition process is kinetically limited and relies on decarbonylation reaction, which provides both challenges and opportunities for ALD implementation and process tuning.
Article
Acoustics
Jorgen Arendt Jensen, Martin Lind Ommen, Sigrid Husebo Oygard, Mikkel Schou, Thomas Sams, Matthias Bo Stuart, Christopher Beers, Erik Vilain Thomsen, Nielse Bent Larsen, Borislav Gueorguiev Tomov
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
(2020)
Article
Engineering, Electrical & Electronic
Andreas Spandet Havreland, Erik Vilain Thomsen
Summary: This paper presents a perturbative analysis of prestressed electrostatic actuated MEMS systems, estimating pull-in voltage using weighted residual method and comparing results with experimental data and Finite Element Model. By incorporating residual stress in the model, improved accuracy in pull-in voltage estimation is achieved, with Richardson extrapolation providing the most precise results.
JOURNAL OF MICROELECTROMECHANICAL SYSTEMS
(2021)
Article
Acoustics
Martin Lind Ommen, Mikkel Schou, Christopher Beers, Jorgen Arendt Jensen, Niels Bent Larsen, Erik Vilain Thomsen
Summary: This study evaluates the use of 3D printed phantoms for calibration of 3D super-resolution ultrasound imaging algorithms. By accurately positioning sub-wavelength sized ultrasound scatterers in a material with properties similar to tissue, the method demonstrates the potential for precise calibration and evaluation of volumetric super-resolution algorithms.
Article
Acoustics
Sigrid H. Oygard, Melanie Audoin, Andreas Austeng, Erik V. Thomsen, Matthias B. Stuart, Jorgen A. Jensen
Summary: A ray tracing method is proposed to predict the position of the transmitted wave in order to improve the usable transmitted field-of-view (FOV) of a row-column array (RCA) with a diverging lens. The method is compared with a simpler thin lens model and shown to increase the usable transmitted FOV.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2022)
Review
Acoustics
Jorgen Arendt Jensen, Mikkel Schou, Lasse Thurmann Jorgensen, Borislav G. Tomov, Matthias Bo Stuart, Marie Sand Traberg, Iman Taghavi, Sigrid Huesebo Oygaard, Martin Lind Ommen, Kitty Steenberg, Erik Vilain Thomsen, Nathalie Sarup Panduro, Michael Bachmann Nielsen, Charlotte Mehlin Sorensen
Summary: Row-column (RC) arrays have the potential to achieve full 3-D ultrasound imaging with a reduced number of elements. By using synthetic aperture sequences and modified beamforming techniques, high-quality anatomic and functional imaging can be achieved. A RC array is also capable of super-resolution imaging and expanding the field of view.
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
(2022)
Article
Acoustics
Sigrid Husebo Oygard, Martin Lind Ommen, Borislav Gueorguiev Tomov, Soren Elmin Diederichsen, Erik Vilain Thomsen, Matthias Bo Stuart, Niels Bent Larsen, Jorgen Arendt Jensen
Summary: This study demonstrates that the nonlinear relationship between voltage and emitted signal in CMUTs can be effectively addressed by using a three-pulse amplitude modulation sequence. Experimental results show that the CMUT and PZT arrays have an average contrast-to-tissue ratio (CTR) enhancement of 37.4 dB and 49.9 dB, respectively, for B-mode and CEUS images with an applied alternating current voltage of 6-60 V. Hydrophone recordings indicate that the nonlinear emissions from CMUTs do not significantly degrade the cancellation in the compounded AM signal, with only 2% of the emitted power between 26 and 60 V AC. Therefore, it is demonstrated that CMUTs can perform CEUS imaging independently of the applied excitation voltage when using a three-pulse AM sequence.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2023)
Article
Acoustics
Mudabbir Tufail Bhatti, Borislav Gueorguiev Tomov, Soren Elmin Diederichsen, Matthias Bo Stuart, Erik Vilain Thomsen, Jorgen Arendt Jensen
Summary: Coded excitation has the potential to enhance image quality and penetration depth, but the increase in operating temperature poses a challenge. This study investigates the ability of CMUTs to handle coded excitation and finds that CMUTs can generate coded excitation signals more effectively at lower temperatures compared to PZT probes.
Proceedings Paper
Acoustics
Stine Lovholt Grue Pedersen, Andreas Spandet Havreland, Ole Hansen, Erik Vilain Thomsen
Summary: This article introduces the importance of the resonance frequency of ultrasound transducers in the field of ultrasound, and proposes a new expression for deriving the resonance frequency in immersion. By considering the influence of the immersion medium, an approximation of the radiation impedance is obtained using the Taylor expansion, and the use of the Fade approximant is suggested for higher precision at smaller aspect ratios.
2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS)
(2022)
Proceedings Paper
Acoustics
Iman Taghavi, Mostafa Amin-Naji, Mikkel Schou, Martin Lind Ommen, Kitty Steenberg, Niels Bent Larsen, Erik Vilain Thomsen, Jorgen Arendt Jensen
Summary: Super-resolution ultrasound imaging (SRI) is a promising technique for visualizing blood vessels with sub-wavelength resolution. This study investigates the impact of microbubble (MB) tracking on image quality and velocity estimation in SRI, with a focus on small-sized vessels. Theoretical modeling, simulation, and measurement results show that the peak velocity of a 3D parabolic velocity profile in 2D imaging is underestimated by approximately 33% when the vessel size is smaller than the resolution limit. This finding suggests that compensation is needed for accurate velocity estimates in SRI.
2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS)
(2022)
Proceedings Paper
Acoustics
Melanie Audoin, Borislav Gueorguiev Tomov, Kasper Flong Pedersen, Jorgen Arendt Jensen, Erik Vilain Thomsen
Summary: This study demonstrates the fabrication of acoustic lenses using a combination of 3D printing and casting or CNC machining techniques, allowing for real-time 3D imaging of large organs. Different lenses made from various materials show different field of view on 2D transducers.
2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS)
(2022)
Proceedings Paper
Acoustics
Mudabbir Tufail Bhatti, Borislav Gueorguiev Tomov, Soren Elmin Diedrichsen, Matthias Bo Stuart, Erik Vilain Thomsen, Jorgen Arendt Jensen
Summary: Coded excitation signals can improve image quality and penetration depth by increasing signal-to-noise ratio. Capacitive Micro-machined Ultrasonic Transducers (CMUTs), which generate less heat compared to Lead Zirconate Titanate (PZT) probes, are believed to be more efficient for coded excitation imaging. Experimental results showed that CMUTs had better thermal efficiency and could emit signals for a longer duration compared to PZTs.
2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS)
(2022)
Proceedings Paper
Acoustics
Jorgen Arendt Jensen, Mikkel Schou, Martin Lind Ommen, Kitty Steenberg, Erik Vilain Thomsen, Borislav G. Tomov, Nathalie Sarup Panduro, Charlotte Mehlin Sorensen, Matthias Bo Stuart
Summary: Row-column (RC) matrix probes can provide volumetric imaging with better resolution and image quality than traditional linear arrays, while maintaining a similar rate.
2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS)
(2022)
Proceedings Paper
Acoustics
Kasper Flong Pedersen, Andreas Spandet Havreland, Erik Vilain Thomsen
Summary: This paper explores the fabrication, characterization, and modeling of delay-line based capacitive micromachined ultrasonic transducers (CMUT). The excellent agreement between theory and measurement in the electrical frequency response modeling is achieved, and a suppression of over -30 dB for electrical crosstalk between adjacent elements is observed in frequencies between 1 MHz and 15 MHz, consistent with the developed model.
INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS 2021)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Sigrid H. Oygard, Martin L. Ommen, Mathias Engholm, Mikkel Schou, Soren E. Diederichsen, Erik Thomsen, Matthias Bo Stuart, Jorgen Arendt Jensen
PROCEEDINGS OF THE 2020 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Kasper F. Pedersen, Mathias Engholm, Andreas S. Havreland, Lars N. Moesner, Christopher Beers, Borislav G. Tomov, Jorgen A. Jensen, Erik Thomsen
PROCEEDINGS OF THE 2020 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)
(2020)
