Catalyst for oxacylation and use of the same

Abstract

This invention relates to a catalyst which comprises palladium metal as the main catalyst, tin metal or a mixture of tin and additional metals as the promoter, in combination with an alkali or alkaline earth metal compound, supported on the outer surface of a porous carrier. The catalyst is used in the process for producing allyl acetate through the oxacylation of propylene, acetic acid and oxygen in a vapor phase. The catalyst of the present invention exhibits high catalytic activity, high catalytic selectivity and high catalytic life, which greatly increases the economic utility of the oxacylation process.

What is claimed is:  
     
         1 . A catalyst for oxacylation, which comprises palladium metal as the main catalyst, tin metal or a mixture of tin and additional metal(s) as the promoter, in combination with an alkali or alkaline earth metal compound, supported on the outer surface of a porous carrier, and being used in the process for producing allyl acetate.  
     
     
         2 . The catalyst according to  claim 1 , which further comprises metal(s) selected from the group consisting of gold, copper, cadmium, bismuth, cerium and a mixture thereof as the additional promoter.  
     
     
         3 . The catalyst according to  claim 1 , wherein the content of said main catalyst, palladium metal, based on the weight of said porous carrier, is in the range of 0.1 to 5.0 weight %.  
     
     
         4 . The catalyst according to  claim 3 , wherein the content of said main catalyst, palladium metal, based on the weight of said porous carrier, is in the range of 0.3 to 1.5 weight %.  
     
     
         5 . The catalyst according to  claim 1 , wherein the content of said promoter, tin metal, based on the weight of said porous carrier, is in the range of 0.01 to 5.0 weight %.  
     
     
         6 . The catalyst according to  claim 5 , wherein the content of said promoter, tin metal, based on the weight of said porous carrier, is in the range of 0.02 to 1.0 weight %.  
     
     
         7 . The catalyst according to  claim 2 , wherein the total content of said promoter, tin metal and additional metal(s), based on the weight of said porous carrier, is in the range of 0.01 to 5.0% by weight.  
     
     
         8 . The catalyst according to  claim 7 , wherein the total content of said promoter, tin metal additional promoter metal(s), based on the weight of said porous carrier, is in the range of 0.02 to 1 0% by weight  
     
     
         9 . The catalyst according to  claim 1 , wherein the content of said alkali or alkaline earth metal compound, based on the weight of said porous carrier, is in the range of 1 to 15 weight %.  
     
     
         10 . The catalyst according to  claim 9 , wherein the content of said alkali or alkaline earth metal compound, based on the weight of said porous carrier, is in the range of 4 to 10 weight %.  
     
     
         11 . The catalyst according to claims  7  or  8 , wherein said additional promoter metal is gold.  
     
     
         12 . The catalyst according to claims  7  or  8 , wherein said additional promoter metal is copper.  
     
     
         13 . The catalyst according to claims  7  or  8 , wherein said additional promoter metal is selected from the group consisting of cadmium, bismuth and cerium.  
     
     
         14 . The catalyst according to  claim 1 , wherein said alkali or alkaline earth metal compounds are the hydroxides, acetates, nitrates and bicarbonates of potassium, sodium, cesium, magnesium and barium.  
     
     
         15 . The catalyst according to  claim 14 , wherein said alkali or alkaline earth metal compounds are the hydroxide, acetate, nitrate and bicarbonate of potassium.  
     
     
         16 . The catalyst according to  claim 1 , wherein said porous carrier is selected from the group consisting of alumina, silica gel, silica, active carbon, silicon carbide, diatomaceous earth, pumice and a mixture thereof..  
     
     
         17 . The catalyst according to  claim 1 , wherein said process for producing allyl acetate is carried out through the oxacylation of propylene, acetic acid, oxygen and water in a vapor phase.  
     
     
         18 . The catalyst according to  claim 17 , wherein the content of water is in the range of 0 to 15 volume %, based on total amount of the reacting gases.  
     
     
         19 . The catalyst according to  claim 18 , wherein the content of water is in the range of 0 to 10 volume %, based on total amount of the reacting gases.  
     
     
         20 . A method for preparing the catalyst according to  claim 1 , which comprises: (a) impregnating a porous carrier with a solution containing palladium and promoter metal(s) in oxidative states, then reducing the metals from an oxidative state into metallic state; (b) impregnating said metallic state metals-supporting carrier with a solution of alkali or alkaline earth metal compounds, then drying it.  
     
     
         21 . The method according to  claim 20 , wherein the reduction reaction for reducing the metals from an oxidative state into a metallic state is carried out in a liquid phase, and the reducing agent used is selected from the group consisting of amines, aldehydes and hydrazines.  
     
     
         22 . The method according to  claim 20 , wherein said reduction reaction for reducing the metals from an oxidative state into a metallic state is carried out in a vapor phase, and the reducing agent used is selected from the group consisting of carbon monoxide, hydrogen and alkene.