6 results about "Rh element" patented technology

The present invention relates to a flower-shaped rhodium-doped β-Ni(OH)2 methanol oxidation electrocatalyst, a preparation method thereof and an application. The rhodium (Rh) element is doped in β-Ni(OH)2, and the Rh-doped β-Ni(OH)2 presents a flower shape and is composed of petal-shaped flakes, all of which are β-type Ni(OH)2. It is prepared by a hydrothermal method in a hydrothermal reaction kettle. When used for methanol oxidation reaction, the anodic oxidation current density can reach 90 mA cm ‑2 , and the Tafel slope is only 40 mV dec ‑1 . The preparation method adopted in the present invention is simple, and the microscopic morphology, size uniformity and stability of the product are good, which is suitable for industrial production; doping with a trace amount of rhodium element significantly reduces the usage amount of precious metals in the preparation process compared with commercial Pd / C and Pt / C catalysts, greatly reducing the production cost, and at the same time reducing the poisoning effect of CO on the catalyst and improving the stability of the catalyst. The doping of rhodium element can inhibit the formation of γ-NiOOH, change the electronic structure of Ni in β-Ni(OH)2, increase the proportion of surface defects in β-Ni(OH)2, reduce the impedance of charge transfer, and thus further improve the catalytic activity.

The invention relates to a supported metal catalyst for selective hydrogenation reaction and a preparation method and application thereof, the catalyst comprises a functional carrier, and a hydrogenation metal active component and an auxiliary metal which are supported on the functional carrier, and the catalyst is characterized in that the functional carrier is a high-silicon Y-type molecular sieve supported with Ag and Ce, the silica-alumina ratio of the high-silicon Y-type molecular sieve is 10-90, and the functional carrier is a high-silicon Y-type molecular sieve supported with Ag and Ce. The specific surface area is greater than or equal to 550m < 2 > / g; the hydrogenation metal active component loaded on the functional carrier comprises one or more of Pd, Pt, Au and Rh elements; the auxiliary metal comprises one or more metal elements selected from Co, Ni, Mo, W, Zn, La and Cu; the hydrogenation metal active component is at least dispersed on the surface of the high-silicon Y-type molecular sieve, and the particle size D50 of the loaded hydrogenation metal active component is 1-20nm.

The invention provides a ternary supported catalyst and a preparation method and application thereof.The ternary supported catalyst comprises a carrier and an auxiliary loaded on the surface of the carrier, the carrier comprises In2O3 and an M-containing oxide, the M-containing oxide comprises ZrO2, Ga2O3 or ZnO, and the auxiliary comprises an Rh element, a Pd element and a Cu element; in the ternary supported catalyst, the content of an Rh element is 1 to 10 weight percent, the content of a Pd element is 0.1 to 5 weight percent, and the content of a Cu element is 0.8 to 10 weight percent. According to the ternary supported catalyst disclosed by the invention, three elements of Rh, Pd and Cu with specific contents are supported on a specific carrier, and the contents of the Rh, Pd and Cu elements in the catalyst are regulated, so that the ternary supported catalyst has the characteristics of high CO2 conversion rate, high methanol selectivity, high methanol space-time yield and the like.

The invention provides a nitrogen-doped carbon carrier confined rhodium-praseodymium double-monatomic catalyst and a preparation method and application thereof.The preparation method includes the steps that 1, Zn (NO3) 2.6 H2O, a precursor of Rh and a precursor of Pr are dispersed in methyl alcohol, and a homogeneous solution A is obtained; the molar ratio of the Rh element to the Pr element is (10-11): (7-8); (2) dissolving 2-methylimidazole in methanol to obtain a homogeneous solution B; (3) mixing the homogeneous solution A and the homogeneous solution B, reacting under pressurization, and centrifuging a reaction product to obtain a first composite solid; (4) washing and drying the first composite solid, and then carrying out heat treatment to obtain a second composite solid; and (5) carrying out acid pickling, suction filtration, drying and grinding on the second composite solid to obtain the nitrogen-doped carbon carrier confined rhodium-praseodymium double-monatomic catalyst. The RhPr / NC double-monatomic catalyst shows excellent hydroxidability and long-term CO poisoning resistance stability under an acidic condition.

The application discloses a catalyst for synthesizing vinyl acetate by an acetylene method and a preparation method and application thereof. The catalyst comprises a carrier, an active component and a metal additive. The metal additive is Rh element. The Rh element exists in the form of Rh 0 and Rh 3+ . The Rh 3+ accounts for 9% to 49% of the total amount of Rh element, and the Rh 0 accounts for 51% to 91% of the total amount of Rh element. The catalyst is used in the reaction of synthesizing vinyl acetate by the acetylene method, and has the advantages of high catalyst activity and less loss of the active component.

The invention belongs to the technical field of precious metal detection, and particularly relates to a method for rapidly detecting the concentration of precious metal in a solution. The method comprises the following steps: detecting an absorbance value of a solution to be detected, wherein precious metals contained in the solution to be detected comprise one or more of a Pd element, a Pt element and an Rh element; and substituting the absorbance value into a linear fitting curve or a linear fitting equation of absorbance value-precious metal element concentration to obtain the concentration of the precious metal element in the solution to be detected. According to the method, the concentration of the noble metal in the solution is detected by adopting the spectrophotometric method, and the spectrophotometric method has the advantages of low equipment cost, high response speed, simplicity and convenience in operation and the like; the method provided by the invention is suitable for real-time quality control in the fields of precious metal extraction, recovery, electrolysis, catalyst preparation and the like; the device can be combined with a continuous flow analysis device or an online monitoring system to realize intelligent detection and data closed loop.