Acrylonitrile synthesis from acetonitrile and methanol over MgMn/ZrO2 catalysts

A series of MgMn/ZrO2 catalysts with different Mn loadings were prepared by an impregnation method. The catalysts were used for the synthesis of acrylonitrile from acetonitrile and methanol. The addition of a suitable amount of Mn exhibited promoting effects on both the activity and the selectivity to acrylonitrile formation. The optimum Mn-content was determined to be Mn/Zr = 0.2 (molar ratio), over which the acrylonitrile yield could reach 13.6%. Based on various characterizations, such as XRD, XPS, SEM, CO2-TPD and nitrogen physisorption, the promoting effect of the Mn-dopant on the catalytic property was mainly attributed to the presence of Mg2MnO4 and the strong(ly) basic site. However, at high Mn content, the activity decreased due to the coverage of the active sites by inactive Mn2O3 and the weak basicity of the catalysts.