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FUNNL: Fast Nonlinear Nonnegative Unmixing for Alternate Energy Systems
Published in Anuj Karpatne, Ramakrishnan Kannan, Vipin Kumar, Knowledge-Guided Machine Learning, 2023
Jeffrey A. Graves, Thomas F. Blum, Piyush Sao, Miaofang Chi, Ramakrishnan Kannan
Palladium is an important catalyst useful for the conversion of carbon monoxide to methane, a critical step in the process of alternative fuel production. Palladium is also used as a catalyst in automotive catalytic converters and fuel cells. The effectiveness of palladium and other catalysts is strongly dependent upon the conditions at their surface [1, 22, 38]. Electron energy loss spectrum (EELS) scanning is a helpful technique that allows scientists to analyze the chemical interactions on a nanometer scale and map chemical distributions, as well as other sub-nanometer phenomena, which is useful for uncovering knowledge about the conditions at the catalyst surface. Carbon is a common support layer used in catalytic reactions and electron microscopy samples, and the carbon EELS signal (the K-edge) overlaps with the palladium signal (the M_4,5-edge). These overlapping signals along with nonlinear interactions between the atomic elements can make interpreting EELS images challenging.
Macrocyclic Receptors for Precious Metal Ions
Published in Satish Kumar, Priya Ranjan Sahoo, Violet Rajeshwari Macwan, Jaspreet Kaur, Mukesh, Rachana Sahney, Macrocyclic Receptors for Environmental and Biosensing Applications, 2022
Satish Kumar, Priya Ranjan Sahoo, Violet Rajeshwari Macwan, Jaspreet Kaur, Mukesh, Rachana Sahney
Additionally, the release and accumulation of palladium from industrial and nuclear wastes in the environment may impact human health adversely. Palladium(II) ions are cytotoxic as they are capable of binding with proteins, DNA, RNA and can cause eye irritations, skin problems, asthma, etc. (Kim et al. 2011; Bai et al. 2013; Berhanu et al. 2019). Various methods such as solvent extraction, ion exchange, membrane transport and adsorption have been explored for palladium enrichment from nuclear wastes. Intensive efforts have been made to make use of the host-guest chemistry to design macrocyclic receptors for effective detection, separation and recovery of palladium.
Activation, Initiation, and Growth of Electroless Nickel Coatings
Published in Fabienne Delaunois, Véronique Vitry, Luiza Bonin, Electroless Nickel Plating, 2019
Esteban Correa, Alejandro Alberto Zuleta Gil, Juan G. Castaño, Félix Echeverría
Furthermore, palladium is part of the platinum-group metals. The commercial value of these metals varies according to their durability, resistance to corrosion, and catalytic properties. For this reason, the price of palladium has been increasing with its application in various industrial sectors (mainly as a catalyst in vehicle gas exhaust pipes), while its reserves constantly decrease. (Vaškelis et al. 2005; Chen et al. 2012). This constant increase in palladium prices prompts the academic, scientific, and industrial communities to search for copper surface activation alternatives. In this sense, it is known as an alternative procedure that effectively activates copper surfaces, allowing for the subsequent formation of electroless nickel coatings. This procedure consists of activating copper surfaces with nickel (Ni-activation). This facilitates the formation of a very thin layer (scarce nanometer thick) of metallic nickel through the reduction of the Ni2+ species. To achieve the thin nickel layer, an excess of thiourea (Tian et al. 2013), Ti3+ ions (Yagi et al. 2005), or formaldehyde (Lin et al. 2016) may be used as a reducing agent. Once the thin layer of metallic nickel is formed, the treated substrate is coated with the desired electroless nickel coating.
Structural Effect of Sulfide-Containing Diamides on the Extraction of Palladium(II) from HCl
Published in Solvent Extraction and Ion Exchange, 2021
Hirokazu Narita, Kazuko Morisaku, Mikiya Tanaka
Palladium is increasingly important for industrial uses, especially for the fabrication of automotive catalytic converters.[1] For the selective recovery of Pd, most major platinum group metal (PGM) refineries currently use solvent extraction methods after leaching PGM into acidic chloride solutions.[2] At the Pd separation stage, separation of Pd over Pt is generally required. However, because Pd and Pt in a relatively concentrated HCl solution both form chloridometalates with the same anionic charge (i.e., [PdCl4]2‒ and [PtCl6]2‒),[3] it is difficult to selectively extract Pd by an anion-exchange reaction. Therefore, coordination-type extractants that induce a ligand-exchange reaction are widely used because of the large difference between the ligand-exchange kinetics of Pd(II) and Pt(IV).[4]
Lifecycle of palladium in Japan: for setting clearance levels of 107Pd
Published in Journal of Nuclear Science and Technology, 2018
Tomoyuki Takahashi, Kayoko Iwata, Sota Tanaka, Naoki Takashima, Tomoyuki Ikawa, Sentaro Takahashi
The Pd demand tripled in the 1990s because of the increased use of Pd in automotive emission control catalysts due to the introduction of stricter standards and legislations on emissions from road vehicles [1,8–10]. The total demand of ∼100 t in 1990 increased to 300 t in 1999; it maintained a similar level thereafter. The worldwide total demand of Pd was 290 t in 2015. Palladium is mainly used as catalysts in automobile exhausts and chemical industries, dental prostheses, electrical devices, and jewellery. The total Pd demand in Japan was 88.5 t in 2015, but the actual domestic consumption (excluding export) was 64 t. Compared with 85 t in 2006, the domestic consumption has gradually decreased during this decade (Figure 1). Palladium is an element that can be recovered and recycled relatively well. In 2015, 28% and 32% of the total supply of Pd was recycled in the world and Japan, respectively. The recovery rate of Pd from catalysts in the chemical industry and from automotive emission control catalysts in Japan is almost 100% and 60%, respectively.
Structural and morphological characteristics of nanocrystalline palladium deposits prepared from ammonia complex by electrodeposition technique
Published in Transactions of the IMF, 2023
K. Ranjithkumar, K. Geetha, V. Prabu, S. M. Senthilkumar, R. Sekar
Palladium (Pd) is one of the most important metals for industrial applications such as catalysis and electrical contacts, because of its solderability, and high catalytic activities for various chemical reactions. The electrodeposition of palladium in an aqueous solution needs a strong complexing agent for stable complex formation. This is because the function of the complexing agent is to shift the potential towards more negative direction and control the free metal ion concentration to a lower level because otherwise the hydrogen evolution reaction will be predominant. Palladium has a high hydrogen absorption capacity.1 The quality of the deposits depends on the electrolyte composition and operating parameters such as current density, mode of current (DC and pulse), factors such as operating temperature, pH, extent of agitation and cathodic polarisation.2 Currently, palladium is widely used in many electronics and automotive industrial applications as a catalyst. This is mainly a result of palladium having high catalytic activity and a lower price in comparison with gold and platinum. The main interest in palladium as an alternative for gold in electrical contacts is twofold: (1) due to its lower cost and (2) because its properties such as ductility and wear resistance are superior to those gold. The palladium deposit from the aqueous electrolyte is light grey. Fewer studies have been reported on the electrodeposition of palladium from aqueous solutions, than gold plating, which has a longer history. Additionally, gold is deposited from cyanide-based solutions which are more toxic and harmful to the environment and human beings.