氧化锆负载磷钨酸催化果糖制备5-羟甲基糠醛

以磷钨酸为活性组分,氧化锆为载体,采用浸渍法制备氧化锆负载磷钨酸催化剂。采用BET、XRD、TG-DTG和FT-IR等分析手段对催化剂物化性能进行了表征。通过催化果糖脱水制备5-羟甲基糠醛(HMF)对催化剂催化性能进行了研究。考察了磷钨酸(TPA)负载量、催化剂用量、反应时间、反应温度、果糖添加量对HMF收率的影响。实验结果表明:TPA负载量为20%,以二甲基亚砜(DMSO)为溶剂,120℃反应90min时,催化剂表现出较高的反应活性,相应HMF的收率为73.3%。催化剂循环使用一次后,HMF的收率下降为42.2%,之后再重复使用,HMF的收率维持在40%左右。反应过程中TPA的流失和腐黑素等杂质在催化剂表面的附着可能是造成催化剂活性降低的原因。

PREPARATION OF 5-HYDROXY METHYL FURFURAL BY DEHYDRATION OF FRUCTOSE WITH TUNGSTOPHOSPHORIC ACID SUPPORTED ON ZIRCONIA

TPA / ZrO 2 catalysts were prepared by impregnation of zirconia with H3PW12O40.The solids were characterized by BET 、 XRD 、 TG-DTG and FT-IR.The TPA / ZrO 2 was evaluated as catalyst for the dehydration of fructose to prepare 5-hydroxymethylfurfural.The effects of TPA loading,catalyst concentration,reaction time and reaction temperature were investigated in detail.With catalyst of 20% TPA loading and DMSO as solvent,HMF yield could be up to 73.3% while reacted at 120℃for 90min.A decrease of the HMF yield from 73.3%to 42.2% was observed in the first catalyst recycling.After that the HMF yield kept approximately at 40%.The loss of the TPA and the adsorption of the rot melanin on the surface of the catalyst may be the main reason for the activity decrease.