负载离子对型酞菁钴双功能硫醇氧化催化剂

Bifunctional Catalysts of Supported Cobalt Phthalocyanine with Oppositively Charged Ions for Autoxidation of Mercaptan

将分别带有正、负电荷基团的季铵盐酞菁钴CoPc[N(CH3 ) 3 I]4 和磺酸盐酞菁钴CoPc(SO3 Na) 4溶解在一起 ,负载在由水滑石热分解而成的MgAl复合氧化物碱性载体上 ,制成负载离子对型酞菁钴催化剂 ,其所具有的碱性、氧化性双功能的特征能够有效地催化 1 辛硫醇氧化 .当这两种酞菁钴配合物的摩尔比为 1时 ,催化活性最高 ,并且稳定性也有较明显的改善 .这种双功能催化剂体系具有酶催化的特点 ,即遵循双底物 ( 1 C8H17SH和O2 )Michaelis Menten动力学规律 ;表观活化能Ea=5 0 .4kJ·mol-1.在一定范围内提高二元酞菁钴混合物的负载量 ,单位酞菁钴中心的活性基本保持恒定 ,表明形成的二聚体络合物可在一定程度上抑制酞菁钴分子的聚集 ,改善催化剂的性能 .同时 ,增大Mg(Al)O载体量即碱中心数 ,有利于催化剂活性和稳定性的提高 .这类新型双功能催化剂具有工业应用的前景 .

The novel bifunctional catalysts for mercaptan autoxidation have been prepared by supporting a mixture of cobalt phthalocyanine tetrasodium sulphonate CoPc(SO 3Na) 4 (CPTS) and Cobalt phthalocyanine tetra(trimethylammonium) iodide CoPc[N(CH 3) 3I] 4 (CPTI) on mixed MgAl oxide ( Mg(A1)O ) derived from thermal decomposition of Mg Al hydrotalcite.The resulting catalysts were examined by the autoxidation reaction of 1 octanethiol.The catalyst shows an increase in reaction rate for the 1 octanethiol autoxidation as compared with an equal amount of catalyst containing CPTS or CPTI alone,and the highest activitiy and stability was achieved when the catalyst containing equimolar amount of CPTS and CPTI was used.This is the result of the matching of positive charge of CPTI and negative charge of CPTS,which prevents the aggregation of Co 2+ centers and the formation of less active peroxo complex: Co(Ⅲ)-O-O-Co(Ⅲ) to a certain degree.The autoxidation reaction catalyzed by these bifunctional catalysts follows two substrate Michaelis Menten kinetics with respect to both of 1 octanethiol and oxygen and the apparent activation energy is 50.4 kJ·mol -1 .