在浸没式双管式陶瓷膜反应器中考察TS-1分子筛上H202氧化苯酚羟基化制苯二酚连续反应的稳定性.研究发现,30 h连续反应过程中,苯二酚选择性保持不变,苯酚转化率逐渐下降.采用场发射扫描电子显微镜结合元素组分分析的测试方法分析使用后的陶瓷膜上的污染物,发现陶瓷膜上吸附少量TS -1催化剂,说明催化剂吸附是造成转化率下降的原因之一.采用X线衍射、紫外可见反射光谱、傅里叶变换红外光谱、N2吸附-脱附以及热分析等测试方法分析反应前后的TS -1催化剂性质,结果表明:经过30 h的连续反应,TS -1分子筛的结晶度、MFI骨架结构和骨架中的钛含量没有显著变化,而其比表面积和孔体积显著降低,说明连续运行过程中产生的有机副产物沉积堵塞分子筛孔道造成TS -1催化剂失活,是导致反应转化率下降的主要原因.%The operation stability of a submerged dual-membrane reactor was evaluated by the phenol hydroxylation to hydroquinone and catechol over TS-1 catalyst. In a 30 h continuous operation, the selectivity remained stable while the conversion decreased gradually. The fresh membrane and the used one were characterized by field emisson scanning electron microscopy ( FESEM) and energy dispersive X-ray spec-troscopy (EDX) analysis. Results showed that some TS-1 catalyst particles aggregated on the membrane surface was one of the reasons for the decrease of phenol conversion. The fresh and used catalysts were characterized by X-ray diffraction ( XRD ) , UV-vis, Fourier transform infrared spectroscopy ( FT-IR ) , N2 adsorption-desorption, and thermogravimetry (TG) analysis techniques. It was found that the crystallini-ty, structure of TS-1 and the content of titanium in the framework did not change obviously. Compared with the fresh catalyst,the channels of the TS-1 used catalyst were blocked by organic by products,leading to the decrease in the surface area and the pore volume for the used catalyst, thus it was the main reason for the decrease of the phenol conversion.
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