Study On Gas-solid Phase Alkylation Of Phenol And Ethanol

O-alkylation (mainly phenyl ether) of phenol with ethanol has gained considerable attention for many years as the products are widely used in variety of applications. Such as organic synthesis, medicine manufacturing,dyes, spices, and inspection of aromatic sulfonic acid. Catalytic synthesis of phenyl ether under the condition of gas-solid has many advantages over the traditional method, and it is a green catalytic technology for environmental friendly. Since the first report of alkylation of phenol with ethanol, many kinds of materials have been investigated as catalysts for the reaction, including various zeiolites and metal oxides. Among them, some solid bases and zeiolites show relatively good catalytic performance.However, the selectivity and stability of catalysts are still unsatisfied for practical applications.In this work,La, Ag and MnO2/Ag modified activated alumina catalysts are prepared by impregnation method,and Al-Ce-P-Ti-O catalysts are prepared by co precipitation method.The catalysts are characterized by means of XRD, BET, IR and SEM etc.The influence of the structure and the active center of the catalyst on the catalytic performance of the alkylation of phenol and ethanol is studied.The results show that the catalyst has better catalytic performance with mesoporous structure, and the active component of the catalyst has an important influence on the alkylation reaction.The addition of MnO2 as the active component of the metal oxide is beneficial to the improvement of the selectivity of phenyl ether.The load of metal and metal oxides and Ce/Al have different catalytic effect of alkylation. Among them, Al-Ce-P-Ti-O and La/Al2O3 shows very high selectivity to phenyl ether, they can reach 100% and 98%, MnO2/Ag/Al2O3 can also reach 96.5%.Meanwhile,the reaction conditions have considerable effect on the catalytic performance,such as reaction time,reaction temperature and flow rate of carrier gas.The results show that when the molar ratio of phenol to ethanol was 1:1, the flow rate of N2 was 50ml/min, the reaction temperature was 250℃, and the four kinds of catalysts show higher catalytic activity. The catalytic activity of Al0.75Ce0.15P1.1Ti0.1 for phenol and ethanol alkylation is the best, and the conversion rate of phenol and the selectivity of phenyl ether is 83.3% and 96.6%.