Single-step conversion of n-butyraldehyde to 2-ethylhexanal

Abstract

Disclosed is a method of making and using a titania supported palladium catalyst for the single step synthesis of 2-ethylhexanal from a feed of n-butyraldehyde. This titania supported palladium catalyst demonstrates high n-butyraldehyde conversion but also produces 2-ethylhexanal in an appreciable yield with maintained activity between runs. This method provides a single step synthesis of 2-ethylhexanal from n-butyraldehyde with a catalyst that can be regenerated that provides cleaner downstream separations relative to the traditional caustic route.

1 .- 13 . (canceled) 
     
     
         14 . A method for preparing a palladium eggshell type catalyst comprising:
 i. dissolving a palladium salt in a solvent to produce a palladium salt-containing solution;   ii. mixing the palladium salt-containing solution with a titania support under atmospheric pressure;   iii. removing said solvent to produce a palladium salt-deposited support; and   iv. reducing said palladium salt-deposited support to form a palladium eggshell type catalyst using a reducing agent selected from the group consisting of: hydrogen gas, hydrogen gas mixtures, alcohol solutions, alcohol/water solutions, hydrazine solutions, and hydrazine/solvent solutions;   
       wherein the palladium shell deposited on the titania support comprises nano-sized particles of palladium having a diameter less than about 10 nanometers; and wherein the palladium shell deposited on the titania support is concentrated within about 300 micrometers of the eggshell type catalyst's exterior surface. 
     
     
         15 . The method according to  claim 14 , wherein the reducing agent is about 10% hydrogen at about 20 SCCM in helium at about 180 SCCM. 
     
     
         16 . The method according to  claim 14 , wherein the reducing agent is about 50% v/v methanol and about 50% v/v water. 
     
     
         17 . The method according to  claim 14 , wherein the reducing agent is about 60% hydrazine and about 30% acetone. 
     
     
         18 . The method according to  claim 15 , wherein the noble metal shells have a particle size of less than about 2 nm. 
     
     
         19 . The method according to  claim 16 , wherein the noble metal shells have a particle size of less than about 5 nm. 
     
     
         20 . The method according to  claim 17 , wherein the noble metal shells have a particle size of less than about 7 nm.