接枝微粒PGMA/SiO_2固载的金属卟啉仿生催化剂的制备

Preparation of PGMA/SiO_2-bound metalloporphyrin biomimetic catalyst

采用"接枝"法将甲基丙烯酸缩水甘油酯(GMA)接枝聚合到硅胶微粒表面,通过环氧键与羟基的开环成醚反应,进而将小分子的对羟基苯基卟啉化学键合在接枝微粒PGMA/SiO2表面,再与金属锰配位,从而制得了PGMA/SiO2固载的金属卟啉仿生催化剂(MnP-PGMA/SiO2);并用红外光谱法和原子吸收光谱法进行了表征;重点研究了对羟基苯基卟啉在接枝微粒PGMA/SiO2表面键合反应的规律;初步考察了MnP-PGMA/SiO2对分子氧氧化乙苯为苯乙酮的催化作用。实验结果表明:在键合反应中以4.5mL三乙胺为催化剂,在70℃下反应8h,可制得卟啉键合量为69.36μmol/g的键合微粒HPP-PGMA/SiO2;HPP-PGMA/SiO2与锰配位时,在64℃下反应8h,得到锰有效配位程度为92.34%的固体催化剂MnP-PGMA/SiO2。在催化分子氧氧化乙苯为苯乙酮的过程中,固体催化剂MnP-PGMA/SiO2具有高的催化活性。

In this paper, poly （glyceryl methacrylate）（PGMA） is bounded to silica by adopting the＂ Grafting from＂ method. The hydroxylphenyl porphyrin is bound to the surface of PGMA/SiO2 via the epoxy bond reacting to the hydroxyl and formed HPP - PGMA/SiO2, Further, the coordination between HPP- PGMA/SiO2 and MnC12 is performed,and PGMA/SiO2 bound manganese porphyrin is gained （ denoted as MnP - PGMA/SiO2 ）. These compounds are characterized by FTIR spectra and atom absorbing spectra. Two factors are examined about the bonding process. The catalyst MnP - PGMA/SiO2 is used in the catalytic oxidation of ethylbenzene using dioxygen as oxygen source at ordinary pressure, and the transform of ethylbonzene into acetophenone is realized. The experimental results show that （hydroxylphenyl） porphyrin and its manganese complex can be favorably bound to the surface of PGMA/SIO2 via opening ring and forming ether. Under the optimal condition, which use 4. 5mL triethylamine as catalyst under 70℃ lasting 8h, the most amount of bounding is 69.36 μmol/g. Manganese ion is chelated with HPP - PGMA/SiO2 under 64℃ lasting 8h. The impact of the chelating reaction is identical with the other method, and the disposal of reaction is very simple. The solid catalyst MnP - PGMA/SiO2 can effectively catalyze the transform of ethylbenzene into acetophenone by dioxygen and exhibits fine catalysis activity.