Palladium on Carbon CAS 7440-05-3 Palladium Black
Previous
Next
Factory Supply Palladium on Carbon CAS 7440-05-3 Palladium Black with Best Price
- Appearance: Black powder
- Purity: 99. 0%min
- Stock: In stock
- Sample: Available
- Zhishang Chemical: Palladium Supplier & Manufacturer
Palladium on Carbon: The Complete Guide
- Item 1: Basic Info of Palladium on Carbon
- Item 2: What is Palladium on Carbon?
- Item 3: Classification and Application of Palladium-Carbon Catalysts
- Item 4: The Manager has Something to Say
- Item 5: Application of Preparation Method of Palladium-Carbon Catalyst
- Item 6: Deactivation and Prevention of Palladium-Carbon Catalyst
- Item 7: Quality Control of Palladium on Carbon
- Item 8: Hot Sale Products
- Item 9: Get Palladium on Carbon Quotation
Palladium on Carbon for Sale
Basic Info of Palladium on Carbon
Basic Info
Chemical Name: | Palladium |
Other Name: | Palladium on carbon; Palladium black; Palladium metaal; Palladium dames; Palladium-carbon catalysts |
CAS: | 7440-05-3 |
EINECS: | 231-115-6 |
Type: | Inorganic salt; Pharmaceutical raw materials |
Molecular Formula: | Pd |
Molecular Weight: | 106.42 |
Chemical Properties
Melting point | 1554 °C(lit.) |
Boiling point | 2970 °C(lit.) |
density | 1.025 g/mL at 25 °C |
storage temp. | no restrictions. |
form | wire |
color | Silver-gray |
Specific Gravity | 12.03 |
Odor | Odorless |
resistivity | 9.96 μΩ-cm, 20°C |
Merck | 14,6989 |
Exposure limits | ACGIH: TWA 1 mg/m3 |
Stability: | Stable. Flammable – fine powder may cause fire or explosion in air. Incompatible with ozone, sodium tetrahydroborate, sulphur, arsenic. |
Other Info
Brand Name: | Zhishang Chemical |
Provide: | Palladium MSDS; Palladium COA |
What is Palladium on Carbon?
Palladium (Pd) belongs to the group VIII element. In general, bulk palladium is silvery white. Its density is about 12.02g/cm3 at 20°C, the melting point is 1550°C, and the boiling point is 2900°C. It has good ductility and plasticity.
As a precious metal, palladium (Pd) is mainly used in the fields of catalysis and precision resistance. The general-sized Pd metal is a silver-white, softer material with good ductility and plasticity, but at the nanoscale size, its morphology and properties have undergone great changes. At ultra-fine size, palladium and its dispersions generally appear black and have a large specific surface area. The most striking thing is the excellent hydrogen absorption properties of Pd. At room temperature and 1 standard atmospheric pressure, palladium metal can absorb hydrogen more than 800 times its own volume. When the pressure is constant, the hydrogen absorption capacity of palladium decreases with the increase of temperature. After hydrogen absorption, its lattice constant can change, the volume becomes larger, and properties such as conductivity also decrease with the increase of hydrogen absorption. The excellent hydrogen absorption ability enables palladium to be widely used in gaseous reactions, especially hydrogenation or dehydrogenation reactions. Therefore, catalysts with palladium as the main active component are the first choice catalysts for various reactions.
Classification and Application of Palladium-Carbon Catalysts
Palladium on carbon (Pd/C) catalyst is a supported catalyst prepared by loading the active component palladium on a carrier activated carbon in a certain way. Although Pd has good catalytic performance, bulk palladium or sponge palladium has poor mechanical properties, poor thermal stability, and relatively expensive price, so it is not suitable for direct use in catalytic reactions. Therefore, people use a carrier with certain mechanical strength, high specific surface area, and suitable chemical properties to support and disperse Pd, so that the above problems have been solved. Activated carbon is widely used as a support for the preparation of palladium-carbon (Pd/C) catalysts due to its high specific surface area, good thermal stability and mechanical strength. Pd/C catalysts have some advantages that homogeneous catalysts do not have, so they have been widely studied and applied.
Classification of Pd/C catalysts
According to the Pd mass fraction (loading capacity) supported on activated carbon, common Pd/C catalysts can be divided into loadings ranging from 0.5wt% to 30wt%, among which, 0.5%, 1%, 1.25% , 3%, 5%, 10% common.
Pd/C catalyst application
Due to the excellent catalytic properties of palladium and the stability and dispersion of Pd on the support, Pd/C catalysts are used in many fields. For example: hydrogenation reactions of alkenes, alkynes, ketones, nitriles, imines, azides, etc., as well as hydrogenolysis reactions of cyclopropane, benzyl ester derivatives, epoxides, hydrazines and halides, etc. It has been widely used, and these reactions involve many industries such as petrochemicals, pharmaceuticals, dyes, and new energy. Pd/C catalyst is the core of catalytic reaction processes such as hydrorefining. Pd/C catalyst has irreplaceable value in various fields, especially in the field of chemical synthesis, and because its carrier is relatively easy to obtain, its application range is very wide.
The Manager has Something to Say
This is William, CEO of Zhishang Chemical Co., Ltd.
Welcome to visit our factory . As the top chemical manufacturer, we have been striving for product quality, innovation , R&D, and customer service for the past 7 years. In the next 10 years or even longer, we are committed to becoming the most reliable chemical supplier in the world , creating a well-known international brand trusted by customers, with the spirit of “one meter wide, ten thousand meters deep”, we continue to focus on product research and development, continue to focus on customer service, continue to improve the supply chain service system, to create a professional chemical supply service team, to achieve win-win long-term cooperation. Please feel free to contact us if you have any questions.
Contact Us
- Email: sales002@sdzschem.com
- Phone: +86 176 5311 3209
- WhatsApp: +86 176 5311 3209
- WeChat: Zhishang17653113209
- Skype: +86 176 5311 3209
Facebook
Twitter
LinkedIn
Pinterest
Email
WhatsApp
If you want to buy palladium on carbon, pls contact us to get a free quote.
Preparation Method of Palladium-Carbon Catalyst
Dipping method
The impregnation method is the easiest method to prepare the catalyst, and it is also the most commonly used method in industry. In most cases, the solution of salts or other compounds that are easily soluble in solvent is used to contact the carrier. After these salts or compounds are loaded on the surface of the carrier, the solvent is volatilized by heating, and then calcined or used with a reducing agent. activate the catalyst.
Dipping precipitation method
The impregnation precipitation method is a common method for many precious metal impregnated catalysts. Since the immersion liquid mostly uses chloride hydrochloric acid solution (such as chloropalladium acid), after the adsorption reaches equilibrium, the immersion liquid is added with sodium hydroxide or sodium carbonate solution and neutralized with hydrochloric acid, so that the chloride is converted into hydroxide and precipitated in The inner pores and surfaces of the carrier.
This method is conducive to the cleaning and removal of chloride ions, and the resulting noble metal compounds can be pre-reduced with an aqueous solution of hydrogen-containing compounds such as hydrazine, formaldehyde and hydrogen peroxide at a lower temperature. The active component precious metal prepared under this condition is easy to reduce, and the particles are relatively fine, and no pollution caused by high-temperature roasting and decomposing chloride occurs.
Ion exchange method
The preparation of catalyst by ion exchange method is to use the ions that can be exchanged on the surface of the carrier, and the active components are loaded on the carrier through ion exchange, and then washed and reduced to make a supported metal catalyst. The introduction of active components in the form of ions can better improve the uniformity of particle size, and is suitable for preparing supported metal or metal ion catalysts with high dispersion, large surface area and uniform distribution, especially suitable for low content and high utilization of metals. Preparation of catalysts.
The ion exchange method is used to prepare the carbon material supported palladium catalyst. At present, the literature only introduces the negatively charged carrier and the metal cation exchange method. The widely used positively charged precursor is the amine complex of palladium. Usually two forms of precursors Pd(NH3)4(N03)2 and Pd(NH3)4Cl2 complexes are used.
Chemical Vapor Deposition
Chemical vapor deposition has many advantages over wetting methods:
- Direct and effective deposition of active substances occurs through the reaction of the carrier surface groups with the gas phase of a suitable volatile organometallic precursor.
- Many steps of the impregnation process are avoided, such as: washing, drying, calcination and reduction.
- Changes in metal dispersion due to high temperature during the calcination and reduction steps are avoided.
The chemical vapor deposition method requires metal precursors to be volatile organometallic compounds, and such precursors generally need to be prepared by themselves.
Deactivation and Prevention of Palladium-Carbon Catalyst
Inactivated
Wear loss of palladium-carbon catalyst
The wear of palladium on carbon catalyst is mainly caused by the following reasons:1) In the process of catalyst transportation, storage and filling, due to vibration and collision, friction occurs between catalyst particles and between catalyst particles and equipment and equipment, causing catalyst powder to fall;
2) During the production process, due to the fluctuation of the liquid level of the reactor, the catalyst active component palladium on the catalyst bed is lost under the direct flushing of the feed solution;
3) If the process adjustment is not timely, if the temperature of the feed material changes too much, the liquid in the hydrogenation kettle will be “flashed”, and the friction between the particles will be intensified.
- Scaling of palladium-carbon catalysts
The side reactions of the oxidation reaction will generate some macromolecular organic compounds and metal corrosion products. These by-products are highly viscous and adsorb on the catalyst surface and micropores, covering a part of the catalyst’s active center and hindering the hydrogenation reaction. Higher levels of these sticky substances can cause catalyst deactivation when the oxidation unit is on and off. Palladium-carbon catalyst poisoning
1) When the impurity concentration contained in the raw material is too high, the active center palladium combines with the impurity, resulting in a decrease in the effective active center concentration, and the catalyst is poisoned. It takes a period of hydrogenation to gradually recover its activity.2) Permanent poisoning
Sulfur can permanently poison the catalyst. After the sulfide (such as sulfate, etc.) enters the reaction system with the raw materials and auxiliary materials, it reacts with palladium to generate dipalladium sulfide or tetrapalladium sulfide, and these two reaction products are reduced to metal elemental palladium with large grains. The activity of palladium is much lower than that of microcrystalline palladium in a highly dispersed state. Therefore, through the above description, it can be determined that palladium carbon will have a partial loss in the production process, and the content will drop a part.
Prevention and improvement measures
- Keep the production running smoothly. Minimize fluctuations in flow and pressure to reduce bed movement; control the reaction temperature to be stable to avoid local overheating of the catalyst bed causing sintering and growth of Pd crystallites; avoid direct friction of particles to produce carbon powder during catalyst storage, transportation and loading. fine grains.
- Strictly control the impurity content in the feed. The impurity content of raw materials PX, acetic acid (HAc), H2, pure water (DIW), and air (AIR) should be strictly controlled, and the corrosion of the reaction system should be reduced to produce metals, so as to prevent the chemical sintering of metals and non-metals from reacting with palladium, resulting in Pd micro-organisms. crystal growth is disabled. In addition, the main poison of palladium-carbon catalyst is sulfur. When the mass fraction of sulfur in the refined feed is 1400×10-6, the bed can be poisoned and completely deactivated within 3 days. The short-term failure of the desulfurization system of the hydrogen production unit can cause The catalyst deactivates rapidly, and the high sulfur content in the air inhaled by oxidation can cause the catalyst to deactivate quickly. The sulfur in production mainly comes from pure water (DIW), hydrogen (H2) and the atmosphere, so necessary measures should be taken to strictly control the sources of each sulfur.
- Optimize the oxidation reaction conditions. Reducing the by-products in the product CTA, macromolecular organics, is an important means to prolong the service life of palladium-carbon catalysts; in addition, appropriately increasing the hydrogenation reaction temperature can reduce the deposition of macromolecular organics on the surface of the catalyst. In recent years, new PTA The reaction temperature of the device has been increased from 280 °C to 288 °C; according to the introduction of relevant patents [6], once it is judged that the system has been deactivated by organic matter coverage, the catalytic activity can be recovered by alkali washing, but the process conditions such as alkali concentration and alkali washing temperature All require strict controls to prevent equipment corrosion, catalyst oxidation and chlorine contamination.
- Due to the difference in the particle size of Pd crystallites and the loss of Pd metal in the catalyst bed, after a period of use, the overall catalytic activity of the catalyst is the strongest in the middle layer, and relatively weak in the upper and lower layers. In order to give full play to the catalytic activity of the catalyst, the service life of the catalyst can be extended by updating the position and surface of the catalyst bed.
Reference
- Palladium – WikiPedia
- Yu Jianmin. The current situation and countermeasures of secondary resource recovery of domestic palladium and platinum[J]. Resource Regeneration, 2007, (1): 46-47.
- He Guodong, Sun Qin, Yang Asan. Preparation of palladium/carbon catalyst and its catalytic performance in the synthesis of 1,3-propanediol[J]. Zhejiang Chemical Industry, 2007, 38(4): 6-14.
Palladium Suppliers and Manufacturers
As a palladium supplier and manufacturer with strict standard product quality system certificate, Zhishang Chemical has long been providing the best palladium raw materials to customers all over the world.
Over the years, relying on professional team experience and customer-centric team concept to meet customer needs in a timely manner, our company enjoys a high reputation in the world. At present, our company has served more than 6,000 customers and has established long-term cooperative relations with customers from many countries.
If you have demand for palladium and related products, please contact our service staff Zhishang Chemical – White directly, we will provide you with high-quality products at the best price.
Quality Control of Palladium on Carbon
Previous
Next
