Selective direct oxidation of 1-butanol into acetal using hydrogen peroxide and Cs 5 MPW 11 (H 2 O)O 39 (M=Fe, Co, Cu) catalysts.

Direct catalytic oxidation of alcohols to acetals in one step process is very attractive, because the two steps process leads firstly to aldehydes, which are unstable species serving as reactive intermediates to generate several by-products reducing process efficiency and selectivity. In this work, a new selective catalytic acetalization of 1-butanol into 1-1-dibutoxybutane acetal using H 2 O 2 in one step process is investigated using Keggin-type polyoxometalates catalysts. The materials developed consisted of new lacunary phophotungstate salts Cs 5 MPW 11 (H 2 O)O 39 (M=Fe, Co and Cu) which were prepared by inorganic solution condensation method and characterized using XRD, IR, SEM and EDX analysis to verify their structure, surface morphology and chemical composition. Cs 5 CuPW 11 (H 2 O)O 39 catalyst allowed the highest performance for the oxidation of 1-butanol at 60 °C using H 2 O 2 excess with a yield approaching 92 % and a turnover number of 784. Such activity is related to a bifunctional behavior of the catalyst as superacid and redox operating system and the synergistic effect created between the [PW 11 O 39 ] 7- Keggin framework, Cs + and Cu 2+ .