Patent ID: 8138115

Claim:
A method of manufacturing a catalyst comprising iron, copper and potassium, comprising: preparing an iron nitrate solution having a Fe 2+ :Fe 3+ ratio (wt %/wt %) in the range of from about 0.01% Fe 2+ :99.99% Fe 3+ to about 100% Fe 2+ :0%Fe 3+ and comprising copper; heating the iron nitrate solution to a temperature in the range of about 20° C. to 80° C.; preparing a precipitating agent solution; reducing the temperature of the iron nitrate solution to a temperature in the range of from about 25° C. to 35° C. to obtain low temperature iron nitrate solution and reducing the temperature of the precipitation agent solution to a temperature in the range of 25° C. to 80° C. to obtain low temperature precipitating agent solution; and precipitating a precipitate comprising iron phases and optionally copper phases by reacting the low temperature nitrate solution with the low temperature precipitating agent at a temperature not exceeding 40° C.