Conversion Single Reagent of n-Propanol to 1,1-Dipropoxypropane Using Cr/Activated Carbon Catalyst

Abstract

Synthesis of 1,1–dipropoxypropane from a single reagent of n-propanol using Cr/Activated Carbon (Cr/AC) as a catalyst has been done. Activated carbon (AC) was prepared by activating coconut shell carbon at 650 °C in the atmosphere of N2 at a flow rate of 20 mL/min for 4 h, and then it was washed using acetone in a Soxhlet for 15 rounds, washed three times by 1.0 M HCl, and finally, it was sieved at 60–80 mesh. Metal content was analyzed using atomic absorption spectroscopy (AAS) and represented by Na, Ca, and Fe. The AC was impregnated with Cr (VI) solution and reduced with H2 at 650 °C. The acidity of the Cr catalyst was determined by the adsorption of ammonia. Optimation of n-propanol conversion to 1,1-dipropoxypropane using Cr/AC catalyst in the atmosphere of N2 was conducted in an oven using variations of temperature of 450, 500, and 550 °C, amount of catalyst of 5, 10, and 15 g, and flow rate of alcohol of 0.10, 0.50, and 0.90 mL/min. The conversions of 1,1-dipropoxypropane were analyzed by GC-MS and 1H-NMR. The results showed that the AC's metal content significantly decreased after washing with acetone and 1.0 M HCl. The AC and Cr/AC had 2.49 and 8.27 mmol/g acidity, respectively. The highest product of 1,1-dipropoxypropane of 65.0% was reached at 450 °C using a 5 g catalyst at a flow rate of the alcohol 0.10 mL/min.