पैलेडियम नैनोकणों की सोनोकेमिकल कमी
Palladium (Pd) is well known for its catalytic properties and is also widely used in materials research, electronics manufacturing, medicine, hydrogen purification, and various chemical applications. Using a sonochemical route, the size and morphology of palladium particles can be controlled by adjusting the PVP/Pd ratio. This enables the ultrasonic synthesis of either very fine, monodisperse nanoparticles or larger palladium aggregates, allowing particle dimensions to be tailored for optimal catalytic performance.
पैलेडियम नैनोकणों का अल्ट्रासोनिक उत्पादन
Ultrasonic palladium nanoparticle reduction offers a fast, reagent-efficient route to Pd(0) nanoparticles by using acoustic cavitation to generate localized high-energy conditions and reducing radicals in solution, enabling palladium ions to be reduced without conventional high-temperature processing.
A key advantage is process control: sonication time and stabilizer concentration, such as the PVP/Pd ratio, can influence whether the product forms as well-dispersed, rounded nanoparticles around 5 nm or as larger aggregates around 20 nm, which is industrially relevant because palladium performance in catalysis depends strongly on particle size, morphology, dispersion, and surface area. Since palladium nanoparticles are widely valuable as heterogeneous catalysts, electrocatalysts, and functional materials, ultrasonic reduction is attractive for producing finely dispersed Pd catalysts under comparatively mild liquid-phase conditions, with potential benefits for chemical synthesis, environmental catalysis, fuel-cell technologies, and other processes where high catalytic activity and efficient noble-metal utilization are economically important.
Industrial nanoparticle processing सोनिकेटर UIP2000hdT के साथ
Sample Preparation Procedure
नमूने निम्नलिखित के रूप में तैयार किए गए थे:
नमूनों के लिए, ईजी के 30 एमएल और 5 · 10 का मिश्रण-6mol of PVP were preprared by magnetic stirring for 15 min. For the different samples, different amount of Pd(NO₃)₂ solution, 1.5mL and 2mL, were added. The sample mixtures were prepared with the ratio of 2·10-3mol Pd(NO₃)₂ in sample (a) and 2.66·10-3mol Pd(NO₃)₂ in sample (b). Both mixtures were sonicated in a 20mL vial using a probe-type ultrasonicator. Samples were taken after sonication times of 30, 60, 90, 120, 150, and 180 min.
प्रयोगात्मक परिणामों के विश्लेषण से पता चलता है कि:
- 1. Pd(II) की Pd(0) में सोनोकेमिकल कमी सोनिकेशन समय पर निर्भर करती है।
- 2. उच्च PVP/Pd(II) दाढ़ अनुपात एक गोल आकार और लगभग 5nm के औसत व्यास वाले मोनोडिस्पर्स्ड पैलेडियम कणों के निर्माण की ओर जाता है।
- 3. हालांकि, कम पीवीपी/पीडी (द्वितीय) दाढ़ अनुपात में 20 एनएम पर केंद्रित बड़े आकार के वितरण के साथ समुच्चय पैलेडियम नैनोकणों को प्राप्त करना शामिल है।
पैलेडियम (II) आयनों को कम करने का सोनोकेमिकल मार्ग पीडी (द्वितीय) पैलेडियम परमाणुओं के लिए पीडी(0) निम्नलिखित माना जा सकता है:
- (1) Water pyrolysis: H₂O → •OH+•H
- (2) Radical formation: RH (Reducing agent) + •OH(•H) → •R + H₂O(H₂)
- (3) आयनों में कमी: पीडी (द्वितीय) + कणों को कम करने (• एच, • आर) → पीडी (0) + आर • सीएचओ + एच +
- (4) कण गठन: Nपीडी (0) → पीडीएन
परिणाम: पीवीपी/पीडी (द्वितीय) अनुपात के आधार पर, छितरी हुई या एकत्रित पीडीN प्राप्त किए गए थे।
Sonochemical reduction of Palladium: sample a (left) contains a high amount of PVP, sample b (right) a low amount of PVP. Sonication time with UP100H: 180 min. Sample a shows mono dispersed Pd nano particles, sample b aggregated Pd nano particles.
Images and study: ©Nemamcha and Rehspringer, 2008
विश्लेषण और परिणाम
यूवी-दृश्यमान अवशोषण विश्लेषण पैलेडियम (II) आयनों की पैलेडियम (0) परमाणुओं में सोनोकेमिकल कमी और अल्ट्रासोनिक क्षेत्र में प्रतिधारण समय के बीच संबंध की पुष्टि करता है। पैलेडियम (II) आयनों की पैलेडियम (0) परमाणुओं में कमी प्रगति करती है और बढ़ती सोनिकेशन समय के साथ पूरी तरह से प्राप्त की जा सकती है। ट्रांसमिशन इलेक्ट्रॉन माइक्रोस्कोपी (टीईएम) के माइक्रोग्राफ बताते हैं कि:
- When a high amount of PVP is added, the sonochemical reduction of palladium ions leads to the formation of monodispersed palladium particles with spherical shape and a mean diameter of approx. 5nm.
- The use of a small quantity of PVP involves the obtaining of aggregates palladium nanoparticles. The dynamic light scattering (DLS) measurements reveal that the palladium nanoparticles aggregates have a large size distribution centered at 20nm.
The lab sonicator UP100H has been used for the preparation of palladium nano-particles.
पैलेडियम (पीडी) नैनो कणों को सोनिकेशन द्वारा तैयार किया जा सकता है
डिजाइन, विनिर्माण और परामर्श – गुणवत्ता जर्मनी में निर्मित
Hielscher अल्ट्रासोनिकेटर अपने उच्चतम गुणवत्ता और डिजाइन मानकों के लिए प्रसिद्ध हैं। मजबूती और आसान संचालन औद्योगिक सुविधाओं में हमारे अल्ट्रासोनिकेटर के सुचारू एकीकरण की अनुमति देता है। किसी न किसी स्थिति और मांग वातावरण आसानी से Hielscher ultrasonicators द्वारा नियंत्रित कर रहे हैं।
Hielscher Ultrasonics एक आईएसओ प्रमाणित कंपनी है और अत्याधुनिक प्रौद्योगिकी और उपयोगकर्ता-मित्रता की विशेषता वाले उच्च प्रदर्शन अल्ट्रासोनिकेटर पर विशेष जोर देती है। बेशक, Hielscher अल्ट्रासोनिकेटर सीई के अनुरूप हैं और उल, सीएसए और RoHs की आवश्यकताओं को पूरा करते हैं।
साहित्य/संदर्भ
- Nemamcha, A.; Rehspringer, J. L. (2008): Morphology of dispersed and aggregated PVV-Pd nanoparticles prepared by ultrasonic irradiation of Pd(NO₃)₂ solution in ethylene glycol. Rev. Adv. Mater. Sci. 18;2008. 685-688.
- Prekob, Á., Muránszky, G., Kocserha, I. et al. (2020): Sonochemical Deposition of Palladium Nanoparticles Onto the Surface of N-Doped Carbon Nanotubes: A Simplified One-Step Catalyst Production Method. Catalysis Letters 150, 2020. 505–513.
- Haitao Zheng, Mphoma S. Matseke, Tshimangadzo S. Munonde (2019): The unique Pd@Pt/C core-shell nanoparticles as methanol-tolerant catalysts using sonochemical synthesis. Ultrasonics Sonochemistry, Volume 57, 2019. 166-171.
जानने के योग्य तथ्य
What is Palladium?
Palladium is a rare, silvery-white precious metal with the chemical symbol Pd and atomic number 46. It belongs to the platinum-group metals and is valued because it is chemically stable, conducts electricity, absorbs hydrogen, and acts as an excellent catalyst. Finely divided palladium is especially effective for hydrogenation and dehydrogenation reactions, and heated palladium can allow hydrogen to diffuse through it, which makes it useful for hydrogen separation and purification.
What are Palladium Nanoparticles Used for?
Palladium nanoparticles are used mainly as high-surface-area catalysts. Because nanoparticles expose far more active surface area than bulk palladium, they can improve catalyst efficiency and reduce the amount of expensive noble metal required. Typical applications include chemical synthesis, hydrogenation reactions, carbon–carbon coupling reactions, electrocatalysis, fuel-cell research, hydrogen sensing and storage, environmental catalysis, and some biomedical research areas such as antimicrobial, photothermal, and anticancer systems. Palladium catalytic behavior depends strongly on particle size, morphology, and dispersion.
Palladium nanoparticles are also used to dope other particles in order to achieve catalytic functionalities. Read more about the ultrasonic pathway to synthesize Pd/N-BCNT as Fischer-Tropsch catalyst!
Is Palladium Toxic?
Elemental metallic palladium is generally considered to have low toxicity and no known biological role, but palladium compounds, salts, dusts, and nanoscale forms should be handled carefully. Occupational or laboratory exposure can cause irritation or sensitization depending on the compound and route of exposure, and palladium chloride solutions, for example, may irritate mucous membranes. For industrial handling, the practical answer is: bulk metallic palladium is relatively low-risk, but palladium powders, soluble palladium salts, and palladium nanoparticles should be treated as potentially hazardous materials, with dust control, ventilation, gloves, eye protection, and proper waste handling.