A dynamic structural behavior of Pt nanoparticles on the ceria surface under reducing/oxidizing conditions was found at moderate temperatures (<500 °C) and exploited to enhance the catalytic activity of Pt/CeO -based exhaust gas catalysts. Redispersion of platinum in an oxidizing atmosphere already occurred at 400 °C. A protocol with reducing pulses at 250-400 °C was applied in a subsequent step for controlled Pt-particle formation. Operando X-ray absorption spectroscopy unraveled the different extent of reduction and sintering of Pt particles: The choice of the reductant allowed the tuning of the reduction degree/particle size and thus the catalytic activity (CO>H >C H ). This dynamic nature of Pt on ceria at such low temperatures (250-500 °C) was additionally confirmed by in situ environmental transmission electron microscopy. A general concept is proposed to adjust the noble metal dispersion (size, structure), for example, during operation of an exhaust gas catalyst.
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http://dx.doi.org/10.1002/anie.201707842 | DOI Listing |
Objective: This study sought to evaluate the value of a CO field-flooding device in cardiopulmonary bypass (CPB) surgical procedures for congenital heart disease (CHD) performed via a right-side small incision approach.
Methods: Between April 2022 and December 2023, 234 children with simple CHD who underwent CPB via a right-side small incision approach were separated into a control group (n = 93) without the use of a CO field-flooding device and a treatment group (n = 141) in which this device was added to the traditional surgical manual exhaust. Demographic, perioperative, arterial blood gas (ABG), and laboratory test data were then compared between these groups of patients.
Nanoscale
January 2025
Chemical Engineering Program, Department of Advanced Science and Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima, Hiroshima 739-8527, Japan.
Highly ordered porous structured particles comprising three-way catalyst (TWC) nanoparticles have attracted attention because of their remarkable catalytic performance. However, the conditions for controlling their pore arrangement to form interconnected pore structures remain unclear. In particular, the correlation between framework thickness (distance between pores) or macroporosity and the diffusion of gaseous reactants to achieve a high catalytic performance has not been extensively discussed.
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January 2025
School of Mechanical Engineering, VIT-AP University, Amaravati, Andhra Pradesh 522237, India.
Waste plastic oils (WPOs) can help address the global energy crisis caused by the rapid depletion of fossil fuels, global warming, and strict emission regulations. The present research delves into the intricate interplay of higher alcohol blends in the context of combustion, performance, and emission characteristics within a common rail direct injection engine. In this regard, 1-hexanol has been selected as the blending constituent for the WPO to tackle emission challenges while concurrently reducing dependence on conventional fuel, as it stands out for its enhanced fuel properties compared to lower alcohols.
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January 2025
Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran.
In this study, a series of experiments are done to analyze the effect of bluff body geometry on the NO reduction of a natural gas-air stratified swirl burner. The stratified burner of Cambridge University is chosen to study the mentioned geometrical effect, and the geometry modification of bluff body is used as a simple method for NO reduction, which can be easily applied to the systems using these burners, including gas turbines. The bluff body geometrical change to an annular bluff body is inspired by the fact that the areas in which the edge of the bluff body is in contact with the unburned flow have lower temperatures, which can drastically affect combustion parameters, especially emissions.
View Article and Find Full Text PDFACS Sens
January 2025
Department of Mechanical Engineering, University of British Columbia, 2054-6250 Applied Science Lane, Vancouver, British Columbia V6T 1Z4, Canada.
Natural gas (NG) is a promising alternative to diesel for sustainable transport, potentially reducing GHG and air quality emissions significantly. However, the GHG benefits hinge on managing methane slip, the unburned methane in the exhaust of NG engines, which carries a significant global warming potential. The CH slip from NG engines is highly dependent on engine type and operation, and effective greenhouse gas emission mitigation requires that the actual operation of real-world engines is monitored.
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