摘要
在2-硝基-4-乙酰胺基苯甲醚(NMA)催化加氢合成2-氨基-4-乙酰胺基苯甲醚(AMA)反应中,规整纳米Pd/C催化剂表现出很好的催化活性和选择性。但Pd/C催化剂在反应的套用过程中表现出反应活性逐渐降低。通过XRD、BET、EDS、XPS等物性表征以及Na2S滴定法和原子吸收法测定Pd含量的研究表明,钯微晶的长大、钯流失、催化剂中毒等不是引起Pd/C催化剂失活的主要原因,而Pd/C催化剂表面金属钯活性位在反应后被2-氨基-4-乙酰胺基苯甲醚产物等有机物覆盖可能是导致其性能逐渐降低的关键。使用酸洗法可以去除反应后Pd/C催化剂表面覆盖的2-氨基-4-乙酰胺基苯甲醚等有机物,释放金属钯活性位,实现Pd/C催化剂的性能有较大程度的恢复;而其他方法对Pd/C催化剂活性恢复的效果不明显。
N-(4-Amino-2-methoxyphenyl)acetamide (AMA) is hydrogenated to form N-(4-nitro-2-methoxyphenyl)acetamide (NMA) over nano-assembled Pd/C catalyst in aqueous phase. The Pd/C catalyst exhibits high activity and selectivity, but it is not good at stability in the aqueous phase. The characterization results of XRD, BET, EDS and XPS for the used Pd/C catalysts indicate that the deactivation of Pd/C catalyst was caused by the absorption and coverage of product AMA on the surface of the catalyst, not caused by the Pd particle growth, Pd leaching or poisoned by S element. After the treatment of the deactivated Pd/C catalyst washed using acetic acid at 100 oC, the catalytic performances of the used Pd/C catalyst could be regenerated due to the removing product covered on the surface of Pd/C catalyst.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2010年第S2期526-529,共4页
Rare Metal Materials and Engineering
基金
浙江省科技厅重大绿色专项(2005C11023-01)
浙江省自然科学基金(Y4080396)
