SU446994A1 - Method of preparing palladium catalyst for liquid-phase oxidation of olefins - Google Patents

Abstract

METHOD OF PREPARING CATALYST Pall-DIE1YUGO / schya ZHIDKOFAZNO- GO olefin oxidation to carbonyl compounds by dissolving the compounds {Chi palshadi in water, .dobavkami promoter metal compounds, characterized in that in order to increase the catalyst activity and selectivity, the compound paJshadi, ppedpochtiteJ [PdCl ^, is dissolved in an aqueous solution of the L-phosphorous-molybdenum-vanadium heteropoly acid prepared by mixing the corresponding salts, oxides of acids, mainly NaPO ^ 12H20, MoO ^ and V ^ Oj, the resulting mixture a- navoshvayut reductant not cleaved yuschim halide ions, e.g. NgH4 "X 1

Description

The invention relates to the field of producing catalysts for the liquid phase oxidation of olefins to carbonyl compounds.

A known method of preparing a catalyst for the liquid phase oxidation of olefins by dissolving pashshdi chloride in water with additives of promoting metals chlorides.

However, this method produces a catalyst with low activity and selectivity.

To increase the activity and selectivity of the catalyst according to the proposed method, palsadium compounds are preferably dissolved in an aqueous solution of phosphorus-molybdenum-vanadium heteropolyacid (PPS) prepared by mixing the corresponding salts, oxides or acids.

Preferably, MoO, reducing with a reducing agent, does not split off halide ions, preferably, and is oxidized with an oxidizing agent, which does not split halides, preferably with air.

To destroy peroxide compounds, which form when the catalyst is used and can cause both equipment corrosion and reduced selectivity due to more sponge oxidation, it is recommended to add a copper compound to the contact solution, for example CuS045H20 at a concentration of 1 mol / l, preferably 10 mol / l .

The catalyst prepared by the proposed method and containing small amounts of chlorine ions is 200 times more than the catalyst prepared by the method known earlier in catalytic activity. Example 1. To prepare 100 MJI of a contact solution containing 0.03 mol tk-b, weighed 11.4 g of Na, P04-12P2 0 (0.3 mol); 25.9 g of MoOj (0.18 mol); 20.5 g VgOg (0.226 g-atom V); 13.0 g, -10 N are dissolved in 150 ml of water with vigorous stirring and boiled for 40 minutes. During the reaction, the solution increases to an intense brown-red ca., dilution. The solution is evaporated to 100 ml and ohh wait to room temperature, the pH is adjusted to 1-1.1 with 10-15 n. , boil for another 20 minutes and the hot solution is filtered twice. With vigorous stirring and boiling, 0.25 g of CuS04 5H, jp is introduced into the solution and in small portions 5.9 g. The solution is foamed, its color changes to blue-green. After boiling for 10-15 minutes, the hot solution is filtered again twice. The filtrate of the recovered solution and the wash water (30 ml) are poured into a 400 ml beaker, and oxidized from the surface with an air flow while boiling and vigorous stirring for 2-3 hours, maintaining a constant volume of 100 ml. Upon reaching olive green coloring, the solution is cooled to. at room temperature and acidified to a pH of 1.0-1.1. The solution turns brown-red. Then, 35 mg of PdClg are poured in, boiled for 20-30 minutes with stirring and air blowing, maintaining the volume equal to 100 ml. The resulting solution contains the following concentrations in mol / l: heteropolyacid with a ratio of P: V: M 1: 7.5: 6 (HPA-6) 0.3; Fd-2 2. 10. At a temperature of 90s and a partial pressure of ethylene and oxygen of 230 mm Hg. the volume of the solution is 0.6 mol, the oxidation rate of ethylene is 6.1 -10 mol, the oxygen reaction rate is 6.42f cIO mol min. Such a catalyst effectively works for 100 hours. Example 2. The preparation of a 100 MP contact solution containing 0.03 mol of P1K-8 ("1: 0.8: 4) is carried out according to the procedure of Example 1. For this, 11.4 g of NazP04- 12H20; 17.3 g 29.5 g 13.0 g N COjIOH O. At the reduction stage, 0.25 g CuSQ is introduced:}. Jc 0 6.5 g. The yield of HPA-8 is 44 g, it is close to the theoretical one, it is considered as one-free HPA-8, the catalyst is insufficiently thermally stable at. After 40 hours of operation at 90 ° C, the hydrolytic cleavage of P1K-8 with the gradual formation of a VO precipitate is observed. The catalyst has high capacity and activity, but it can be used for processes that are not superior.

Claims (1)

METHOD FOR PREPARING A PALLADIUM CATALYST FOR LIQUID PHASE OXIDATION OF OLEFINS into carbonyl compounds by dissolving a palladium compound in water, with additions of promoter metal compounds,