3 results about "Rh element" patented technology

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.