Ethylphosphonic acid, 85 percent orthophosphoric acid and aluminum nitrate were dissolved in water and pH was increased to 5 by ammonia water; precipitates were formed which were separated by filtration and dried; 10 percent alumina sol was added and catalyst calcined at 250 C for 3 hours to give a molded, weakly acidic solid catalyst T=200°C; P=7500.75 Torr;
