Alumina was purchased from Piyush chemicals, Ahmedabad
and all other chemicals were purchased from Akar Enterprise,
Ahmedabad. The catalyst was prepared by impregnation of alumina
with an aqueous solution of potassium nitrate. For this purpose,
30 ml of (35%) Potassium nitrate was loaded onto 10 gm of
alumina by an impregnation method, followed by drying in atmospheric
dryer. Prior to each reaction, the catalysts were calcined in
a muffle furnace at desired temperatures (typically at 773 K) in air
for 4 h [5]. The alumina used as a support had a surface area of
126 m2/g.