摘要
钼铋系催化剂在丙烯氧化制丙烯醛反应中具有独特优势,但对反应温度、水汽配比的要求均较高.金催化剂的低温催化性能优异且对产物选择性高,我们结合两者的优势,通过调变载体制备过程中沉淀终止时的p H值得到了一系列多组分复合氧化物担载金催化剂(Au/MBFCN).反应结果显示,p H=4、载金量为0.5%(质量分数)时得到的催化剂Au/MBFCN-4性能较优,在水汽配比5%(体积分数)、反应温度300℃下,丙烯转化率可达22.9%,丙烯醛选择性为91.2%.用HRTEM、XRD、Raman和XPS等对催化剂进行表征,发现pH值较低时得到的催化剂中Mo O_(3)、Bi_(2)Mo_(3)O_(12)、Fe_(2)(Mo O_(4))_(3)等活性晶相的含量较多,是Au/MBFCN-4低温催化性能优异的主要原因.
Molybdenum-bismuth catalysts have unique advantages in propylene oxidation to acrolein.Higher reaction temperature and water vapor ratio,however,are required.Taking the advantages of gold catalysts with excellent catalytic performance at low temperature and high selectivity to product,we prepared a series of multi-component composite oxide supported gold catalysts(Au/MBFCN)by adjusting the pH at the termination of precipitation during the preparation of the support.The reaction results showed that the catalyst Au/MBFCN-4 with pH=4 and gold loading of 0.5%(Mass fraction)presented nice performance.The propylene conversion of 22.9%and acrolein selectivity of 91.2%was achieved at the temperature of 300℃when water vapor reduced to 5%(Volume Fraction).The catalysts were characterized by HRTEM,XRD,Raman and XPS,and it was found that the catalyst obtained at low pH contained more active crystal phases such as MoO_(3),Bi_(2)Mo_(3)O_(12),Fe_(2)(MoO_(4))_(3),which was the main reason for the excellent catalytic performance of Au/MBFCN-4 at low temperature.
作者
赵亚俐
孙逊
闫啸
刘野淳子
苏慧娟
祁彩霞
ZHAO Ya-li;SUN Xun;YAN Xiao;LIU Ye-chun-zi;SU Hui-juan;QI Cai-xia(Yantai Key Laboratory of Gold Catalysis and Engineering,Shandong Applied Research Center of Gold Nanotechnology,College of Chemistry&Chemical Engineering,Yantai University,Yantai 264005,China)
出处
《分子催化》
CAS
CSCD
北大核心
2021年第6期538-548,I0003,共12页
Journal of Molecular Catalysis(China)
基金
国家自然科学基金(21773202,21802117)
烟台市重点研发计划(2019LJRC140,2021XDHZ068)。
关键词
钼铋系复合氧化物
纳米金
丙烯选择氧化
丙烯醛
molybdenum-bismuth composite oxide
nano-gold
selective oxidation of propylene
acrolein
