Effect of acidity and copper surface area of the Cu/Al2O3 catalyst prepared by electroless plating procedure on dehydrogenation reactions

Abstract

Two industrially important dehydrogenation reactions were catalyzed with Cu/γ-Al₂O₃ catalyst prepared by the electroless copper plating technique. One is the dehydrogenation of cyclohexanol and the other is the dehydrogenation of isopropanol to realize the catalytic activity of these catalysts on cyclic and noncyclic alcohols. The dehydrogenation activity strongly depends on the number of exposed copper sites and the dehydration activity clearly influences the effective acid sites of the catalysts. The copper surface area increases with loading up to ca. 15 wt.% Cu; above this loading the reduction of copper surface area was observed. The efficiency of the acid site is almost same and is independent of the preparation method up to the lower copper loading range. But at high copper content the efficiency of the acid site is relatively low when compared with the catalysts prepared by the urea hydrolysis procedure. Though the acid amount of the catalysts prepared by the electroless method was higher than that of the catalysts prepared by the urea hydrolysis procedure, the selectivity to cyclohexene was relatively low.