摘要
在微型固定床连续流动反应装置上评价催化剂,研究了碱金属离子对合成愈创木酚催化剂AlPTiSbO性能的影响,结果显示碱金属离子对催化剂有较大的影响。优化了催化剂中钠离子的含量,发现最佳的钠铝原子比为0.045。在此催化剂上,280℃,常压下,愈创木酚的选择性为98%,邻苯二酚的转化率达到92%,催化剂稳定性也明显增加。采用BET,XRD,XPS和NH3-TPD等技术对催化剂进行了表征。结果显示,添加钠离子后,催化剂的比表面积有所增加;催化剂中磷酸盐(钠)含量增加;催化剂的表面酸强度降低。
A series of AIPTiSbO catalysts with various alkali metal carbonate additives was investigated to elucidate the effects of additives on the catalytic properties of AlPTiSbO catalysts in the synthesis of guaiacol with eatehol and methanol. The synthesis reaction was carried out in a continuous-flow reactor at 280℃ under atmospheric pressure. The catalytic properties of the AlPTiSbO catalysts were strongly affected by the additives. It was demonstrated that Na^＋ could improve the activity of catalysts greatly. The sodium loading was optimized. The highest activity was achieved when the atomic ratio of Na to Al was 0.045. Selectivity to guaiacol was above 98% and conversion of catechol was 92% on the optimized catalyst. The catalysts were characterized by BET, XPS, XRD and temperature-programmed desorption of NH3. The addition of alkali metal increased the BET surface areas. The increase in stabilities of the sodium-modified catalysts was not only due to the promotional effects of the formation of Na3PO4 in the reaction but also decreased concentration of acid sites on the surface of catalysts.
出处
《广州化工》
CAS
2009年第4期104-106,113,共4页
GuangZhou Chemical Industry
