CoMg氧化物催化氧化合成对羟基苯甲醛

Synthesis of p-hydroxybenzaldehyde using CoMg-oxide as catalyst

以对甲酚为原料,γ-Al2O3负载钴镁氧化物为催化剂,催化氧化合成标题化合物。考察了催化剂制备条件对催化剂性能的影响,得到较佳的催化剂制备工艺为:醋酸钴和硝酸镁的浓度分别为1.25和0.21 mol/L,焙烧温度750℃,焙烧时间2 h。对甲酚的转化率和对羟基苯甲醛的选择性分别为91%和96%。实验发现,制备催化剂时加入硝酸镁,可大大提高催化活性和产物选择性。通过XRD结果说明,钴镁氧化物之所以有较高的催化活性,是因为催化剂在制备过程中形成了MgCo4氧化物物相。

CoMg-oxide supported on γ-Al2O3 was used as the catalyst for the synthesis of p-hydroxybenzaldehyde from p-cresol.The effect of conditions for preparation of catalyst was investigated.The optimum conditions were as follows：The concentration of Co（OAc）2 and Mg（NO3）2 was 1.25 and 0.21 mol/L;respectively,the calcination temperature was 750 ℃ and the calcination time was equal to 2 h.The conversion of p-cresol resached 91%,while the selectivity of p-hydroxybenzaldehyde was equal to 96%.Test results showed that impregnating Mg（NO3）2 and Co（OAc）2 on γ-Al2O3 led to a higher activity of p-cresol conversion and excellent selectivity for p-hydroxybenzaldehyde than the case for impregnating Co（OAc）2 on γ-Al2O3.According to the XRD analysis,MgCo4 oxide was formed by calcination,resulting in a better catalytic activity.